citus/src/test/regress/expected/multi_router_planner.out

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SET citus.next_shard_id TO 840000;
-- ===================================================================
-- test router planner functionality for single shard select queries
-- ===================================================================
-- all the tests in this file is intended for testing non-fast-path
-- router planner, so we're disabling it in this file. We've bunch of
-- other tests that triggers fast-path-router planner
SET citus.enable_fast_path_router_planner TO false;
CREATE SCHEMA multi_router_planner;
SET search_path TO multi_router_planner;
CREATE TABLE articles_hash (
id bigint NOT NULL,
author_id bigint NOT NULL,
title varchar(20) NOT NULL,
word_count integer
);
CREATE TABLE articles_range (
id bigint NOT NULL,
author_id bigint NOT NULL,
title varchar(20) NOT NULL,
word_count integer
);
CREATE TABLE articles_append (
id bigint NOT NULL,
author_id bigint NOT NULL,
title varchar(20) NOT NULL,
word_count integer
);
-- Check for the existence of line 'DEBUG: Creating router plan'
-- to determine if router planner is used.
-- this table is used in a CTE test
CREATE TABLE authors_hash ( name varchar(20), id bigint );
CREATE TABLE authors_range ( name varchar(20), id bigint );
CREATE TABLE authors_reference ( name varchar(20), id bigint );
-- this table is used in router executor tests
CREATE TABLE articles_single_shard_hash (LIKE articles_hash);
SET citus.shard_replication_factor TO 1;
SELECT create_distributed_table('articles_hash', 'author_id', 'hash', shard_count := 2);
create_distributed_table
---------------------------------------------------------------------
(1 row)
SELECT create_distributed_table('articles_single_shard_hash', 'author_id', 'hash', shard_count := 1);
create_distributed_table
---------------------------------------------------------------------
(1 row)
SELECT create_reference_table('authors_reference');
create_reference_table
---------------------------------------------------------------------
(1 row)
-- create a bunch of test data
INSERT INTO articles_hash VALUES ( 1, 1, 'arsenous', 9572);
INSERT INTO articles_hash VALUES ( 2, 2, 'abducing', 13642);
INSERT INTO articles_hash VALUES ( 3, 3, 'asternal', 10480);
INSERT INTO articles_hash VALUES ( 4, 4, 'altdorfer', 14551);
INSERT INTO articles_hash VALUES ( 5, 5, 'aruru', 11389);
INSERT INTO articles_hash VALUES ( 6, 6, 'atlases', 15459);
INSERT INTO articles_hash VALUES ( 7, 7, 'aseptic', 12298);
INSERT INTO articles_hash VALUES ( 8, 8, 'agatized', 16368);
INSERT INTO articles_hash VALUES ( 9, 9, 'alligate', 438);
INSERT INTO articles_hash VALUES (10, 10, 'aggrandize', 17277);
INSERT INTO articles_hash VALUES (11, 1, 'alamo', 1347);
INSERT INTO articles_hash VALUES (12, 2, 'archiblast', 18185);
INSERT INTO articles_hash VALUES (13, 3, 'aseyev', 2255);
INSERT INTO articles_hash VALUES (14, 4, 'andesite', 19094);
INSERT INTO articles_hash VALUES (15, 5, 'adversa', 3164);
INSERT INTO articles_hash VALUES (16, 6, 'allonym', 2);
INSERT INTO articles_hash VALUES (17, 7, 'auriga', 4073);
INSERT INTO articles_hash VALUES (18, 8, 'assembly', 911);
INSERT INTO articles_hash VALUES (19, 9, 'aubergiste', 4981);
INSERT INTO articles_hash VALUES (20, 10, 'absentness', 1820);
INSERT INTO articles_hash VALUES (21, 1, 'arcading', 5890);
INSERT INTO articles_hash VALUES (22, 2, 'antipope', 2728);
INSERT INTO articles_hash VALUES (23, 3, 'abhorring', 6799);
INSERT INTO articles_hash VALUES (24, 4, 'audacious', 3637);
INSERT INTO articles_hash VALUES (25, 5, 'antehall', 7707);
INSERT INTO articles_hash VALUES (26, 6, 'abington', 4545);
INSERT INTO articles_hash VALUES (27, 7, 'arsenous', 8616);
INSERT INTO articles_hash VALUES (28, 8, 'aerophyte', 5454);
INSERT INTO articles_hash VALUES (29, 9, 'amateur', 9524);
INSERT INTO articles_hash VALUES (30, 10, 'andelee', 6363);
INSERT INTO articles_hash VALUES (31, 1, 'athwartships', 7271);
INSERT INTO articles_hash VALUES (32, 2, 'amazon', 11342);
INSERT INTO articles_hash VALUES (33, 3, 'autochrome', 8180);
INSERT INTO articles_hash VALUES (34, 4, 'amnestied', 12250);
INSERT INTO articles_hash VALUES (35, 5, 'aminate', 9089);
INSERT INTO articles_hash VALUES (36, 6, 'ablation', 13159);
INSERT INTO articles_hash VALUES (37, 7, 'archduchies', 9997);
INSERT INTO articles_hash VALUES (38, 8, 'anatine', 14067);
INSERT INTO articles_hash VALUES (39, 9, 'anchises', 10906);
INSERT INTO articles_hash VALUES (40, 10, 'attemper', 14976);
INSERT INTO articles_hash VALUES (41, 1, 'aznavour', 11814);
INSERT INTO articles_hash VALUES (42, 2, 'ausable', 15885);
INSERT INTO articles_hash VALUES (43, 3, 'affixal', 12723);
INSERT INTO articles_hash VALUES (44, 4, 'anteport', 16793);
INSERT INTO articles_hash VALUES (45, 5, 'afrasia', 864);
INSERT INTO articles_hash VALUES (46, 6, 'atlanta', 17702);
INSERT INTO articles_hash VALUES (47, 7, 'abeyance', 1772);
INSERT INTO articles_hash VALUES (48, 8, 'alkylic', 18610);
INSERT INTO articles_hash VALUES (49, 9, 'anyone', 2681);
INSERT INTO articles_hash VALUES (50, 10, 'anjanette', 19519);
SET client_min_messages TO 'DEBUG2';
-- insert a single row for the test
INSERT INTO articles_single_shard_hash VALUES (50, 10, 'anjanette', 19519);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
-- single-shard tests
-- test simple select for a single row
SELECT * FROM articles_hash WHERE author_id = 10 AND id = 50;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
id | author_id | title | word_count
---------------------------------------------------------------------
50 | 10 | anjanette | 19519
(1 row)
-- get all titles by a single author
SELECT title FROM articles_hash WHERE author_id = 10;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
title
---------------------------------------------------------------------
aggrandize
absentness
andelee
attemper
anjanette
(5 rows)
-- try ordering them by word count
SELECT title, word_count FROM articles_hash
WHERE author_id = 10
ORDER BY word_count DESC NULLS LAST;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
title | word_count
---------------------------------------------------------------------
anjanette | 19519
aggrandize | 17277
attemper | 14976
andelee | 6363
absentness | 1820
(5 rows)
-- look at last two articles by an author
SELECT title, id FROM articles_hash
WHERE author_id = 5
ORDER BY id
LIMIT 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 5
title | id
---------------------------------------------------------------------
aruru | 5
adversa | 15
(2 rows)
-- find all articles by two authors in same shard
-- but plan is not router executable due to order by
SELECT title, author_id FROM articles_hash
WHERE author_id = 7 OR author_id = 8
ORDER BY author_id ASC, id;
DEBUG: Creating router plan
title | author_id
---------------------------------------------------------------------
aseptic | 7
auriga | 7
arsenous | 7
archduchies | 7
abeyance | 7
agatized | 8
assembly | 8
aerophyte | 8
anatine | 8
alkylic | 8
(10 rows)
-- same query is router executable with no order by
SELECT title, author_id FROM articles_hash
WHERE author_id = 7 OR author_id = 8;
DEBUG: Creating router plan
title | author_id
---------------------------------------------------------------------
aseptic | 7
agatized | 8
auriga | 7
assembly | 8
arsenous | 7
aerophyte | 8
archduchies | 7
anatine | 8
abeyance | 7
alkylic | 8
(10 rows)
-- add in some grouping expressions, still on same shard
-- having queries unsupported in Citus
SELECT author_id, sum(word_count) AS corpus_size FROM articles_hash
WHERE author_id = 1 OR author_id = 7 OR author_id = 8 OR author_id = 10
GROUP BY author_id
HAVING sum(word_count) > 1000
ORDER BY sum(word_count) DESC;
DEBUG: Creating router plan
author_id | corpus_size
---------------------------------------------------------------------
10 | 59955
8 | 55410
7 | 36756
1 | 35894
(4 rows)
-- however having clause is supported if it goes to a single shard
SELECT author_id, sum(word_count) AS corpus_size FROM articles_hash
WHERE author_id = 1
GROUP BY author_id
HAVING sum(word_count) > 1000
ORDER BY sum(word_count) DESC;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
author_id | corpus_size
---------------------------------------------------------------------
1 | 35894
(1 row)
-- query is a single shard query but can't do shard pruning,
-- not router-plannable due to <= and IN
SELECT * FROM articles_hash WHERE author_id <= 1 ORDER BY id;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
SELECT * FROM articles_hash WHERE author_id IN (1, 3) ORDER BY id;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
3 | 3 | asternal | 10480
11 | 1 | alamo | 1347
13 | 3 | aseyev | 2255
21 | 1 | arcading | 5890
23 | 3 | abhorring | 6799
31 | 1 | athwartships | 7271
33 | 3 | autochrome | 8180
41 | 1 | aznavour | 11814
43 | 3 | affixal | 12723
(10 rows)
SELECT * FROM articles_hash WHERE author_id IN (1, NULL) ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- queries with CTEs are supported
WITH first_author AS MATERIALIZED ( SELECT id FROM articles_hash WHERE author_id = 1)
SELECT * FROM first_author;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id
---------------------------------------------------------------------
1
11
21
31
41
(5 rows)
-- SELECT FOR UPDATE is supported if not involving reference table
BEGIN;
WITH first_author AS MATERIALIZED (
SELECT articles_hash.id, auref.name FROM articles_hash, authors_reference auref
WHERE author_id = 2 AND auref.id = author_id
FOR UPDATE
)
UPDATE articles_hash SET title = first_author.name
FROM first_author WHERE articles_hash.author_id = 2 AND articles_hash.id = first_author.id;
DEBUG: Router planner doesn't support SELECT FOR UPDATE in common table expressions involving reference tables.
DEBUG: generating subplan XXX_1 for CTE first_author: SELECT articles_hash.id, auref.name FROM multi_router_planner.articles_hash, multi_router_planner.authors_reference auref WHERE ((articles_hash.author_id OPERATOR(pg_catalog.=) 2) AND (auref.id OPERATOR(pg_catalog.=) articles_hash.author_id)) FOR UPDATE OF articles_hash FOR UPDATE OF auref
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
DEBUG: Plan XXX query after replacing subqueries and CTEs: UPDATE multi_router_planner.articles_hash SET title = first_author.name FROM (SELECT intermediate_result.id, intermediate_result.name FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, name character varying(20))) first_author WHERE ((articles_hash.author_id OPERATOR(pg_catalog.=) 2) AND (articles_hash.id OPERATOR(pg_catalog.=) first_author.id))
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
WITH first_author AS MATERIALIZED (
SELECT id, word_count FROM articles_hash WHERE author_id = 2
FOR UPDATE
)
UPDATE articles_hash SET title = first_author.word_count::text
FROM first_author WHERE articles_hash.author_id = 2 AND articles_hash.id = first_author.id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
-- Without FOR UPDATE this is router plannable
WITH first_author AS MATERIALIZED (
SELECT articles_hash.id, auref.name FROM articles_hash, authors_reference auref
WHERE author_id = 2 AND auref.id = author_id
)
UPDATE articles_hash SET title = first_author.name
FROM first_author WHERE articles_hash.author_id = 2 AND articles_hash.id = first_author.id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
ROLLBACK;
-- queries with CTEs are supported even if CTE is not referenced inside query
WITH first_author AS MATERIALIZED ( SELECT id FROM articles_hash WHERE author_id = 1)
SELECT title FROM articles_hash WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
title
---------------------------------------------------------------------
arsenous
alamo
arcading
athwartships
aznavour
(5 rows)
-- two CTE joins are supported if they go to the same worker
WITH id_author AS MATERIALIZED ( SELECT id, author_id FROM articles_hash WHERE author_id = 1),
id_title AS MATERIALIZED (SELECT id, title from articles_hash WHERE author_id = 1)
SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | id | title
---------------------------------------------------------------------
1 | 1 | 1 | arsenous
11 | 1 | 11 | alamo
21 | 1 | 21 | arcading
31 | 1 | 31 | athwartships
41 | 1 | 41 | aznavour
(5 rows)
WITH id_author AS MATERIALIZED ( SELECT id, author_id FROM articles_hash WHERE author_id = 1),
id_title AS MATERIALIZED (SELECT id, title from articles_hash WHERE author_id = 3)
SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id;
DEBUG: Creating router plan
id | author_id | id | title
---------------------------------------------------------------------
(0 rows)
-- CTE joins are supported because they are both planned recursively
WITH id_author AS MATERIALIZED ( SELECT id, author_id FROM articles_hash WHERE author_id = 1),
id_title AS MATERIALIZED (SELECT id, title from articles_hash WHERE author_id = 2)
SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id;
DEBUG: cannot run command which targets multiple shards
DEBUG: generating subplan XXX_1 for CTE id_author: SELECT id, author_id FROM multi_router_planner.articles_hash WHERE (author_id OPERATOR(pg_catalog.=) 1)
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
DEBUG: generating subplan XXX_2 for CTE id_title: SELECT id, title FROM multi_router_planner.articles_hash WHERE (author_id OPERATOR(pg_catalog.=) 2)
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT id_author.id, id_author.author_id, id_title.id, id_title.title FROM (SELECT intermediate_result.id, intermediate_result.author_id FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, author_id bigint)) id_author, (SELECT intermediate_result.id, intermediate_result.title FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, title character varying(20))) id_title WHERE (id_author.id OPERATOR(pg_catalog.=) id_title.id)
DEBUG: Creating router plan
id | author_id | id | title
---------------------------------------------------------------------
(0 rows)
-- recursive CTEs are supported when filtered on partition column
CREATE TABLE company_employees (company_id int, employee_id int, manager_id int);
SELECT create_distributed_table('company_employees', 'company_id', 'hash', shard_count := 4);
create_distributed_table
---------------------------------------------------------------------
(1 row)
INSERT INTO company_employees values(1, 1, 0);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
INSERT INTO company_employees values(1, 2, 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
INSERT INTO company_employees values(1, 3, 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
INSERT INTO company_employees values(1, 4, 2);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
INSERT INTO company_employees values(1, 5, 4);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
INSERT INTO company_employees values(3, 1, 0);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 3
INSERT INTO company_employees values(3, 15, 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 3
INSERT INTO company_employees values(3, 3, 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 3
-- find employees at top 2 level within company hierarchy
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 1 and manager_id = 0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id AND
ce.company_id = 1))
SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
company_id | employee_id | manager_id | level
---------------------------------------------------------------------
1 | 1 | 0 | 1
1 | 2 | 1 | 2
1 | 3 | 1 | 2
(3 rows)
-- query becomes not router plannble and gets rejected
-- if filter on company is dropped
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 1 and manager_id = 0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id))
SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: Router planner cannot handle multi-shard select queries
ERROR: recursive CTEs are not supported in distributed queries
-- logically wrong query, query involves different shards
-- from the same table
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 3 and manager_id = 0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id AND
ce.company_id = 2))
SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: cannot run command which targets multiple shards
ERROR: recursive CTEs are not supported in distributed queries
-- Test router modifying CTEs
WITH new_article AS MATERIALIZED(
INSERT INTO articles_hash VALUES (1, 1, 'arsenous', 9) RETURNING *
)
SELECT * FROM new_article;
DEBUG: only SELECT, UPDATE, or DELETE common table expressions may be router planned
DEBUG: generating subplan XXX_1 for CTE new_article: INSERT INTO multi_router_planner.articles_hash (id, author_id, title, word_count) VALUES (1, 1, 'arsenous'::character varying, 9) RETURNING id, author_id, title, word_count
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT id, author_id, title, word_count FROM (SELECT intermediate_result.id, intermediate_result.author_id, intermediate_result.title, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, author_id bigint, title character varying(20), word_count integer)) new_article
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9
(1 row)
WITH update_article AS MATERIALIZED(
UPDATE articles_hash SET word_count = 10 WHERE id = 1 AND word_count = 9 RETURNING *
)
SELECT * FROM update_article;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: generating subplan XXX_1 for CTE update_article: UPDATE multi_router_planner.articles_hash SET word_count = 10 WHERE ((id OPERATOR(pg_catalog.=) 1) AND (word_count OPERATOR(pg_catalog.=) 9)) RETURNING id, author_id, title, word_count
DEBUG: Creating router plan
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT id, author_id, title, word_count FROM (SELECT intermediate_result.id, intermediate_result.author_id, intermediate_result.title, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, author_id bigint, title character varying(20), word_count integer)) update_article
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 10
(1 row)
WITH update_article AS MATERIALIZED (
UPDATE articles_hash SET word_count = 11 WHERE id = 1 AND word_count = 10 RETURNING *
)
SELECT coalesce(1,random());
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: generating subplan XXX_1 for CTE update_article: UPDATE multi_router_planner.articles_hash SET word_count = 11 WHERE ((id OPERATOR(pg_catalog.=) 1) AND (word_count OPERATOR(pg_catalog.=) 10)) RETURNING id, author_id, title, word_count
DEBUG: Creating router plan
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT COALESCE((1)::double precision, random()) AS "coalesce"
DEBUG: Creating router plan
coalesce
---------------------------------------------------------------------
1
(1 row)
WITH update_article AS MATERIALIZED (
UPDATE articles_hash SET word_count = 10 WHERE author_id = 1 AND id = 1 AND word_count = 11 RETURNING *
)
SELECT coalesce(1,random());
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
coalesce
---------------------------------------------------------------------
1
(1 row)
WITH update_article AS MATERIALIZED (
UPDATE authors_reference SET name = '' WHERE id = 0 RETURNING *
)
SELECT coalesce(1,random());
DEBUG: cannot router plan modification of a non-distributed table
DEBUG: generating subplan XXX_1 for CTE update_article: UPDATE multi_router_planner.authors_reference SET name = ''::character varying WHERE (id OPERATOR(pg_catalog.=) 0) RETURNING name, id
DEBUG: Creating router plan
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT COALESCE((1)::double precision, random()) AS "coalesce"
DEBUG: Creating router plan
coalesce
---------------------------------------------------------------------
1
(1 row)
WITH delete_article AS MATERIALIZED (
DELETE FROM articles_hash WHERE id = 1 AND word_count = 10 RETURNING *
)
SELECT * FROM delete_article;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: generating subplan XXX_1 for CTE delete_article: DELETE FROM multi_router_planner.articles_hash WHERE ((id OPERATOR(pg_catalog.=) 1) AND (word_count OPERATOR(pg_catalog.=) 10)) RETURNING id, author_id, title, word_count
DEBUG: Creating router plan
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT id, author_id, title, word_count FROM (SELECT intermediate_result.id, intermediate_result.author_id, intermediate_result.title, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, author_id bigint, title character varying(20), word_count integer)) delete_article
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 10
(1 row)
-- Modifying statement in nested CTE case is covered by PostgreSQL itself
WITH new_article AS MATERIALIZED(
WITH nested_cte AS MATERIALIZED(
INSERT INTO articles_hash VALUES (1, 1, 'arsenous', 9572) RETURNING *
)
SELECT * FROM nested_cte
)
SELECT * FROM new_article;
ERROR: WITH clause containing a data-modifying statement must be at the top level
-- Modifying statement in a CTE in subquery is also covered by PostgreSQL
SELECT * FROM (
WITH new_article AS MATERIALIZED (
INSERT INTO articles_hash VALUES (1, 1, 'arsenous', 9572) RETURNING *
)
SELECT * FROM new_article
) AS subquery_cte;
ERROR: WITH clause containing a data-modifying statement must be at the top level
-- grouping sets are supported on single shard
SELECT
id, substring(title, 2, 1) AS subtitle, count(*)
FROM articles_hash
WHERE author_id = 1 or author_id = 3
GROUP BY GROUPING SETS ((id),(subtitle))
ORDER BY id, subtitle;
DEBUG: Creating router plan
id | subtitle | count
---------------------------------------------------------------------
1 | | 1
3 | | 1
11 | | 1
13 | | 1
21 | | 1
23 | | 1
31 | | 1
33 | | 1
41 | | 1
43 | | 1
| b | 1
| f | 1
| l | 1
| r | 2
| s | 2
| t | 1
| u | 1
| z | 1
(18 rows)
-- grouping sets are not supported on multiple shards
SELECT
id, substring(title, 2, 1) AS subtitle, count(*)
FROM articles_hash
WHERE author_id = 1 or author_id = 2
GROUP BY GROUPING SETS ((id),(subtitle))
ORDER BY id, subtitle;
DEBUG: Router planner cannot handle multi-shard select queries
ERROR: could not run distributed query with GROUPING SETS, CUBE, or ROLLUP
HINT: Consider using an equality filter on the distributed table's partition column.
-- queries which involve functions in FROM clause are supported if it goes to a single worker.
SELECT * FROM articles_hash, position('om' in 'Thomas') WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count | position
---------------------------------------------------------------------
1 | 1 | arsenous | 9572 | 3
11 | 1 | alamo | 1347 | 3
21 | 1 | arcading | 5890 | 3
31 | 1 | athwartships | 7271 | 3
41 | 1 | aznavour | 11814 | 3
(5 rows)
SELECT * FROM articles_hash, position('om' in 'Thomas') WHERE author_id = 1 or author_id = 3;
DEBUG: Creating router plan
id | author_id | title | word_count | position
---------------------------------------------------------------------
1 | 1 | arsenous | 9572 | 3
3 | 3 | asternal | 10480 | 3
11 | 1 | alamo | 1347 | 3
13 | 3 | aseyev | 2255 | 3
21 | 1 | arcading | 5890 | 3
23 | 3 | abhorring | 6799 | 3
31 | 1 | athwartships | 7271 | 3
33 | 3 | autochrome | 8180 | 3
41 | 1 | aznavour | 11814 | 3
43 | 3 | affixal | 12723 | 3
(10 rows)
-- they are supported via (sub)query pushdown if multiple workers are involved
SELECT * FROM articles_hash, position('om' in 'Thomas') WHERE author_id = 1 or author_id = 2 ORDER BY 4 DESC, 1 DESC, 2 DESC LIMIT 5;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: push down of limit count: 5
id | author_id | title | word_count | position
---------------------------------------------------------------------
12 | 2 | archiblast | 18185 | 3
42 | 2 | ausable | 15885 | 3
2 | 2 | abducing | 13642 | 3
41 | 1 | aznavour | 11814 | 3
32 | 2 | amazon | 11342 | 3
(5 rows)
-- unless the query can be transformed into a join
SELECT * FROM articles_hash
WHERE author_id IN (SELECT author_id FROM articles_hash WHERE author_id = 2)
ORDER BY articles_hash.id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
id | author_id | title | word_count
---------------------------------------------------------------------
2 | 2 | abducing | 13642
12 | 2 | archiblast | 18185
22 | 2 | antipope | 2728
32 | 2 | amazon | 11342
42 | 2 | ausable | 15885
(5 rows)
-- subqueries are supported in FROM clause but they are not router plannable
SELECT articles_hash.id,test.word_count
FROM articles_hash, (SELECT id, word_count FROM articles_hash) AS test WHERE test.id = articles_hash.id
ORDER BY test.word_count DESC, articles_hash.id LIMIT 5;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: generating subplan XXX_1 for subquery SELECT id, word_count FROM multi_router_planner.articles_hash
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT articles_hash.id, test.word_count FROM multi_router_planner.articles_hash, (SELECT intermediate_result.id, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, word_count integer)) test WHERE (test.id OPERATOR(pg_catalog.=) articles_hash.id) ORDER BY test.word_count DESC, articles_hash.id LIMIT 5
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: push down of limit count: 5
id | word_count
---------------------------------------------------------------------
50 | 19519
14 | 19094
48 | 18610
12 | 18185
46 | 17702
(5 rows)
SELECT articles_hash.id,test.word_count
FROM articles_hash, (SELECT id, word_count FROM articles_hash) AS test
WHERE test.id = articles_hash.id and articles_hash.author_id = 1
ORDER BY articles_hash.id;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: generating subplan XXX_1 for subquery SELECT id, word_count FROM multi_router_planner.articles_hash
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT articles_hash.id, test.word_count FROM multi_router_planner.articles_hash, (SELECT intermediate_result.id, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, word_count integer)) test WHERE ((test.id OPERATOR(pg_catalog.=) articles_hash.id) AND (articles_hash.author_id OPERATOR(pg_catalog.=) 1)) ORDER BY articles_hash.id
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | word_count
---------------------------------------------------------------------
1 | 9572
11 | 1347
21 | 5890
31 | 7271
41 | 11814
(5 rows)
-- subqueries are not supported in SELECT clause
SELECT a.title AS name, (SELECT a2.id FROM articles_single_shard_hash a2 WHERE a.id = a2.id LIMIT 1)
AS special_price FROM articles_hash a;
DEBUG: Router planner cannot handle multi-shard select queries
ERROR: complex joins are only supported when all distributed tables are co-located and joined on their distribution columns
-- simple lookup query
SELECT *
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- below query hits a single shard, router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1 OR author_id = 17;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- below query hits two shards, not router plannable + not router executable
-- handled by real-time executor
SELECT *
FROM articles_hash
WHERE author_id = 1 OR author_id = 18
ORDER BY 4 DESC, 3 DESC, 2 DESC, 1 DESC;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
41 | 1 | aznavour | 11814
1 | 1 | arsenous | 9572
31 | 1 | athwartships | 7271
21 | 1 | arcading | 5890
11 | 1 | alamo | 1347
(5 rows)
-- rename the output columns
SELECT id as article_id, word_count * id as random_value
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
article_id | random_value
---------------------------------------------------------------------
1 | 9572
11 | 14817
21 | 123690
31 | 225401
41 | 484374
(5 rows)
-- we can push down co-located joins to a single worker
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id
LIMIT 3;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
first_author | second_word_count
---------------------------------------------------------------------
10 | 17277
10 | 1820
10 | 6363
(3 rows)
-- following join is router plannable since the same worker
-- has both shards when citus.enable_non_colocated_router_query_pushdown
-- is enabled
SET citus.enable_non_colocated_router_query_pushdown TO ON;
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id
ORDER BY 1,2 LIMIT 3;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
first_author | second_word_count
---------------------------------------------------------------------
10 | 19519
10 | 19519
10 | 19519
(3 rows)
SET citus.enable_non_colocated_router_query_pushdown TO OFF;
-- but this is not the case otherwise
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id
ORDER BY 1,2 LIMIT 3;
DEBUG: router planner does not support queries that reference non-colocated distributed tables
DEBUG: push down of limit count: 3
DEBUG: join prunable for task partitionId 0 and 1
DEBUG: join prunable for task partitionId 0 and 2
DEBUG: join prunable for task partitionId 0 and 3
DEBUG: join prunable for task partitionId 1 and 0
DEBUG: join prunable for task partitionId 1 and 2
DEBUG: join prunable for task partitionId 1 and 3
DEBUG: join prunable for task partitionId 2 and 0
DEBUG: join prunable for task partitionId 2 and 1
DEBUG: join prunable for task partitionId 2 and 3
DEBUG: join prunable for task partitionId 3 and 0
DEBUG: join prunable for task partitionId 3 and 1
DEBUG: join prunable for task partitionId 3 and 2
DEBUG: pruning merge fetch taskId 1
DETAIL: Creating dependency on merge taskId 2
DEBUG: pruning merge fetch taskId 2
DETAIL: Creating dependency on merge taskId 2
DEBUG: pruning merge fetch taskId 4
DETAIL: Creating dependency on merge taskId 4
DEBUG: pruning merge fetch taskId 5
DETAIL: Creating dependency on merge taskId 4
DEBUG: pruning merge fetch taskId 7
DETAIL: Creating dependency on merge taskId 6
DEBUG: pruning merge fetch taskId 8
DETAIL: Creating dependency on merge taskId 6
DEBUG: pruning merge fetch taskId 10
DETAIL: Creating dependency on merge taskId 8
DEBUG: pruning merge fetch taskId 11
DETAIL: Creating dependency on merge taskId 8
ERROR: the query contains a join that requires repartitioning
HINT: Set citus.enable_repartition_joins to on to enable repartitioning
RESET citus.enable_non_colocated_router_query_pushdown;
-- following join is not router plannable since there are no
-- workers containing both shards, but will work through recursive
-- planning
WITH single_shard as MATERIALIZED(SELECT * FROM articles_single_shard_hash)
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, single_shard b
WHERE a.author_id = 2 and a.author_id = b.author_id
LIMIT 3;
DEBUG: found no worker with all shard placements
DEBUG: generating subplan XXX_1 for CTE single_shard: SELECT id, author_id, title, word_count FROM multi_router_planner.articles_single_shard_hash
DEBUG: Creating router plan
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT a.author_id AS first_author, b.word_count AS second_word_count FROM multi_router_planner.articles_hash a, (SELECT intermediate_result.id, intermediate_result.author_id, intermediate_result.title, intermediate_result.word_count FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(id bigint, author_id bigint, title character varying(20), word_count integer)) b WHERE ((a.author_id OPERATOR(pg_catalog.=) 2) AND (a.author_id OPERATOR(pg_catalog.=) b.author_id)) LIMIT 3
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
first_author | second_word_count
---------------------------------------------------------------------
(0 rows)
-- single shard select with limit is router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1
LIMIT 3;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
(3 rows)
-- single shard select with limit + offset is router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1
LIMIT 2
OFFSET 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
(2 rows)
-- single shard select with limit + offset + order by is router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id desc
LIMIT 2
OFFSET 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
31 | 1 | athwartships | 7271
21 | 1 | arcading | 5890
(2 rows)
-- single shard select with group by on non-partition column is router plannable
SELECT id
FROM articles_hash
WHERE author_id = 1
GROUP BY id
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id
---------------------------------------------------------------------
1
11
21
31
41
(5 rows)
-- single shard select with distinct is router plannable
SELECT DISTINCT id
FROM articles_hash
WHERE author_id = 1
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id
---------------------------------------------------------------------
1
11
21
31
41
(5 rows)
-- single shard aggregate is router plannable
SELECT avg(word_count)
FROM articles_hash
WHERE author_id = 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
avg
---------------------------------------------------------------------
12356.400000000000
(1 row)
-- max, min, sum, count are router plannable on single shard
SELECT max(word_count) as max, min(word_count) as min,
sum(word_count) as sum, count(word_count) as cnt
FROM articles_hash
WHERE author_id = 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
max | min | sum | cnt
---------------------------------------------------------------------
18185 | 2728 | 61782 | 5
(1 row)
-- queries with aggregates and group by supported on single shard
SELECT max(word_count)
FROM articles_hash
WHERE author_id = 1
GROUP BY author_id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
max
---------------------------------------------------------------------
11814
(1 row)
-- router plannable union queries are supported
SELECT * FROM (
SELECT * FROM articles_hash WHERE author_id = 1
UNION
SELECT * FROM articles_hash WHERE author_id = 3
) AS combination
ORDER BY id;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
3 | 3 | asternal | 10480
11 | 1 | alamo | 1347
13 | 3 | aseyev | 2255
21 | 1 | arcading | 5890
23 | 3 | abhorring | 6799
31 | 1 | athwartships | 7271
33 | 3 | autochrome | 8180
41 | 1 | aznavour | 11814
43 | 3 | affixal | 12723
(10 rows)
(SELECT LEFT(title, 1) FROM articles_hash WHERE author_id = 1)
UNION
(SELECT LEFT(title, 1) FROM articles_hash WHERE author_id = 3);
DEBUG: Creating router plan
left
---------------------------------------------------------------------
a
(1 row)
(SELECT LEFT(title, 1) FROM articles_hash WHERE author_id = 1)
INTERSECT
(SELECT LEFT(title, 1) FROM articles_hash WHERE author_id = 3);
DEBUG: Creating router plan
left
---------------------------------------------------------------------
a
(1 row)
SELECT * FROM (
SELECT LEFT(title, 2) FROM articles_hash WHERE author_id = 1
EXCEPT
SELECT LEFT(title, 2) FROM articles_hash WHERE author_id = 3
) AS combination
ORDER BY 1;
DEBUG: Creating router plan
left
---------------------------------------------------------------------
al
ar
at
az
(4 rows)
-- top-level union queries are supported through recursive planning
SET client_min_messages to 'NOTICE';
(
(SELECT * FROM articles_hash WHERE author_id = 1)
UNION
(SELECT * FROM articles_hash WHERE author_id = 3)
)
UNION
(SELECT * FROM articles_hash WHERE author_id = 2)
ORDER BY 1,2,3;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
2 | 2 | abducing | 13642
3 | 3 | asternal | 10480
11 | 1 | alamo | 1347
12 | 2 | archiblast | 18185
13 | 3 | aseyev | 2255
21 | 1 | arcading | 5890
22 | 2 | antipope | 2728
23 | 3 | abhorring | 6799
31 | 1 | athwartships | 7271
32 | 2 | amazon | 11342
33 | 3 | autochrome | 8180
41 | 1 | aznavour | 11814
42 | 2 | ausable | 15885
43 | 3 | affixal | 12723
(15 rows)
-- unions in subqueries are supported with subquery pushdown
SELECT * FROM (
(SELECT * FROM articles_hash WHERE author_id = 1)
UNION
(SELECT * FROM articles_hash WHERE author_id = 2)) uu
ORDER BY 1, 2
LIMIT 5;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
2 | 2 | abducing | 13642
11 | 1 | alamo | 1347
12 | 2 | archiblast | 18185
21 | 1 | arcading | 5890
(5 rows)
-- error out for queries with repartition jobs
SELECT *
FROM articles_hash a, articles_hash b
WHERE a.id = b.id AND a.author_id = 1;
ERROR: the query contains a join that requires repartitioning
HINT: Set citus.enable_repartition_joins to on to enable repartitioning
-- by setting enable_repartition_joins we can make this query run
SET citus.enable_repartition_joins TO ON;
SELECT *
FROM articles_hash a, articles_hash b
WHERE a.id = b.id AND a.author_id = 1
ORDER BY 1 DESC;
id | author_id | title | word_count | id | author_id | title | word_count
---------------------------------------------------------------------
41 | 1 | aznavour | 11814 | 41 | 1 | aznavour | 11814
31 | 1 | athwartships | 7271 | 31 | 1 | athwartships | 7271
21 | 1 | arcading | 5890 | 21 | 1 | arcading | 5890
11 | 1 | alamo | 1347 | 11 | 1 | alamo | 1347
1 | 1 | arsenous | 9572 | 1 | 1 | arsenous | 9572
(5 rows)
SET citus.enable_repartition_joins TO OFF;
-- queries which hit more than 1 shards are not router plannable or executable
-- handled by real-time executor
SELECT *
FROM articles_hash
WHERE author_id >= 1 AND author_id <= 3
ORDER BY 1,2,3,4;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
2 | 2 | abducing | 13642
3 | 3 | asternal | 10480
11 | 1 | alamo | 1347
12 | 2 | archiblast | 18185
13 | 3 | aseyev | 2255
21 | 1 | arcading | 5890
22 | 2 | antipope | 2728
23 | 3 | abhorring | 6799
31 | 1 | athwartships | 7271
32 | 2 | amazon | 11342
33 | 3 | autochrome | 8180
41 | 1 | aznavour | 11814
42 | 2 | ausable | 15885
43 | 3 | affixal | 12723
(15 rows)
-- Test various filtering options for router plannable check
SET client_min_messages to 'DEBUG2';
-- this is definitely single shard
-- and router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1 and author_id >= 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- not router plannable due to or
SELECT *
FROM articles_hash
WHERE author_id = 1 or id = 1;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1 and (id = 1 or id = 41);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
41 | 1 | aznavour | 11814
(2 rows)
-- router plannable
SELECT *
FROM articles_hash
WHERE author_id = 1 and (id = random()::int * 0);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- not router plannable due to function call on the right side
SELECT *
FROM articles_hash
WHERE author_id = (random()::int * 0 + 1);
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- not router plannable due to or
SELECT *
FROM articles_hash
WHERE author_id = 1 or id = 1;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable due to abs(-1) getting converted to 1 by postgresql
SELECT *
FROM articles_hash
WHERE author_id = abs(-1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- not router plannable due to abs() function
SELECT *
FROM articles_hash
WHERE 1 = abs(author_id);
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- not router plannable due to abs() function
SELECT *
FROM articles_hash
WHERE author_id = abs(author_id - 2);
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable, function on different field
SELECT *
FROM articles_hash
WHERE author_id = 1 and (id = abs(id - 2));
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
(1 row)
-- not router plannable due to is true
SELECT *
FROM articles_hash
WHERE (author_id = 1) is true;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable, (boolean expression) = true is collapsed to (boolean expression)
SELECT *
FROM articles_hash
WHERE (author_id = 1) = true;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable, between operator is on another column
SELECT *
FROM articles_hash
WHERE (author_id = 1) and id between 0 and 20;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
(2 rows)
-- router plannable, partition column expression is and'ed to rest
SELECT *
FROM articles_hash
WHERE (author_id = 1) and (id = 1 or id = 31) and title like '%s';
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
31 | 1 | athwartships | 7271
(2 rows)
-- router plannable, order is changed
SELECT *
FROM articles_hash
WHERE (id = 1 or id = 31) and title like '%s' and (author_id = 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
31 | 1 | athwartships | 7271
(2 rows)
-- router plannable
SELECT *
FROM articles_hash
WHERE (title like '%s' or title like 'a%') and (author_id = 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable
SELECT *
FROM articles_hash
WHERE (title like '%s' or title like 'a%') and (author_id = 1) and (word_count < 3000 or word_count > 8000);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
41 | 1 | aznavour | 11814
(3 rows)
SELECT LAG(title, 1) over (ORDER BY word_count) prev, title, word_count
FROM articles_hash
WHERE author_id = 5;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 5
prev | title | word_count
---------------------------------------------------------------------
| afrasia | 864
afrasia | adversa | 3164
adversa | antehall | 7707
antehall | aminate | 9089
aminate | aruru | 11389
(5 rows)
SELECT LAG(title, 1) over (ORDER BY word_count) prev, title, word_count
FROM articles_hash
WHERE author_id = 5
ORDER BY word_count DESC;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 5
prev | title | word_count
---------------------------------------------------------------------
aminate | aruru | 11389
antehall | aminate | 9089
adversa | antehall | 7707
afrasia | adversa | 3164
| afrasia | 864
(5 rows)
SELECT id, MIN(id) over (order by word_count)
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | min
---------------------------------------------------------------------
11 | 11
21 | 11
31 | 11
1 | 1
41 | 1
(5 rows)
SELECT id, word_count, AVG(word_count) over (order by word_count)
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | word_count | avg
---------------------------------------------------------------------
11 | 1347 | 1347.0000000000000000
21 | 5890 | 3618.5000000000000000
31 | 7271 | 4836.0000000000000000
1 | 9572 | 6020.0000000000000000
41 | 11814 | 7178.8000000000000000
(5 rows)
SELECT word_count, rank() OVER (PARTITION BY author_id ORDER BY word_count)
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
word_count | rank
---------------------------------------------------------------------
1347 | 1
5890 | 2
7271 | 3
9572 | 4
11814 | 5
(5 rows)
SELECT id, MIN(id) over (order by word_count)
FROM articles_hash
WHERE author_id = 1 or author_id = 2
ORDER BY 1;
DEBUG: Router planner cannot handle multi-shard select queries
id | min
---------------------------------------------------------------------
1 | 1
2 | 1
11 | 11
12 | 1
21 | 11
22 | 11
31 | 11
32 | 1
41 | 1
42 | 1
(10 rows)
SELECT LAG(title, 1) over (ORDER BY word_count) prev, title, word_count
FROM articles_hash
WHERE author_id = 5 or author_id = 2
ORDER BY 2;
DEBUG: Router planner cannot handle multi-shard select queries
prev | title | word_count
---------------------------------------------------------------------
aruru | abducing | 13642
antipope | adversa | 3164
| afrasia | 864
aminate | amazon | 11342
antehall | aminate | 9089
adversa | antehall | 7707
afrasia | antipope | 2728
ausable | archiblast | 18185
amazon | aruru | 11389
abducing | ausable | 15885
(10 rows)
-- where false queries are router plannable
SELECT *
FROM articles_hash
WHERE false;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT *
FROM articles_hash
WHERE author_id = 1 and false;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT *
FROM articles_hash
WHERE author_id = 1 and 1=0;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- Even if the where clause contains "false", the query is not router
-- plannable when citus.enable_non_colocated_router_query_pushdown
-- is disabled. This is because, the tables are not colocated.
SET citus.enable_non_colocated_router_query_pushdown TO ON;
-- the same query, router plannable
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id and false;
DEBUG: Creating router plan
first_author | second_word_count
---------------------------------------------------------------------
(0 rows)
SET citus.enable_non_colocated_router_query_pushdown TO OFF;
-- the same query, _not_ router plannable
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id and false;
DEBUG: router planner does not support queries that reference non-colocated distributed tables
first_author | second_word_count
---------------------------------------------------------------------
(0 rows)
RESET citus.enable_non_colocated_router_query_pushdown;
SELECT *
FROM articles_hash
WHERE null;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- where false with immutable function returning false
SELECT *
FROM articles_hash a
WHERE a.author_id = 10 and int4eq(1, 2);
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT *
FROM articles_hash a
WHERE int4eq(1, 2);
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id and int4eq(1, 1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 10
first_author | second_word_count
---------------------------------------------------------------------
10 | 19519
10 | 19519
10 | 19519
10 | 19519
10 | 19519
(5 rows)
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id and int4eq(1, 2);
DEBUG: Creating router plan
first_author | second_word_count
---------------------------------------------------------------------
(0 rows)
-- partition_column is null clause does not prune out any shards,
-- all shards remain after shard pruning, not router plannable
SELECT *
FROM articles_hash a
WHERE a.author_id is null;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- partition_column equals to null clause prunes out all shards
-- no shards after shard pruning, router plannable
SELECT *
FROM articles_hash a
WHERE a.author_id = null;
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- stable function returning bool
SELECT *
FROM articles_hash a
WHERE date_ne_timestamp('1954-04-11', '1954-04-11'::timestamp);
DEBUG: Creating router plan
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT a.author_id as first_author, b.word_count as second_word_count
FROM articles_hash a, articles_single_shard_hash b
WHERE a.author_id = 10 and a.author_id = b.author_id and
date_ne_timestamp('1954-04-11', '1954-04-11'::timestamp);
DEBUG: Creating router plan
first_author | second_word_count
---------------------------------------------------------------------
(0 rows)
-- union/difference /intersection with where false
-- this query was not originally router plannable, addition of 1=0
-- makes it router plannable
SELECT * FROM (
SELECT * FROM articles_hash WHERE author_id = 1
UNION
SELECT * FROM articles_hash WHERE author_id = 2 and 1=0
) AS combination
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
SELECT * FROM (
SELECT * FROM articles_hash WHERE author_id = 1
EXCEPT
SELECT * FROM articles_hash WHERE author_id = 2 and 1=0
) AS combination
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
(SELECT * FROM articles_hash WHERE author_id = 1)
INTERSECT
(SELECT * FROM articles_hash WHERE author_id = 2 and 1=0);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- if these queries get routed, they would fail since number1() does not exist
-- on workers. This tests an exceptional case in which some local tables bypass
-- checks.
CREATE OR REPLACE FUNCTION number1(OUT datid int)
RETURNS SETOF int
AS $$
DECLARE
BEGIN
RETURN QUERY SELECT 1;
END;
$$ LANGUAGE plpgsql;
DEBUG: switching to sequential query execution mode
DETAIL: A command for a distributed function is run. To make sure subsequent commands see the function correctly we need to make sure to use only one connection for all future commands
SELECT 1 FROM authors_reference r JOIN (
SELECT s.datid FROM number1() s LEFT JOIN pg_database d ON s.datid = d.oid
) num_db ON (r.id = num_db.datid) LIMIT 1;
DEBUG: found no worker with all shard placements
DEBUG: function does not have co-located tables
DEBUG: generating subplan XXX_1 for subquery SELECT datid FROM multi_router_planner.number1() s(datid)
DEBUG: Creating router plan
DEBUG: generating subplan XXX_2 for subquery SELECT s.datid FROM ((SELECT intermediate_result.datid FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(datid integer)) s LEFT JOIN pg_database d ON (((s.datid)::oid OPERATOR(pg_catalog.=) d.oid)))
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT 1 FROM (multi_router_planner.authors_reference r JOIN (SELECT intermediate_result.datid FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(datid integer)) num_db ON ((r.id OPERATOR(pg_catalog.=) num_db.datid))) LIMIT 1
DEBUG: Creating router plan
?column?
---------------------------------------------------------------------
(0 rows)
-- same scenario with a view
CREATE VIEW num_db AS
SELECT s.datid FROM number1() s LEFT JOIN pg_database d ON s.datid = d.oid;
SELECT 1 FROM authors_reference r JOIN num_db ON (r.id = num_db.datid) LIMIT 1;
DEBUG: found no worker with all shard placements
DEBUG: function does not have co-located tables
DEBUG: generating subplan XXX_1 for subquery SELECT datid FROM multi_router_planner.number1() s(datid)
DEBUG: Creating router plan
DEBUG: generating subplan XXX_2 for subquery SELECT s.datid FROM ((SELECT intermediate_result.datid FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(datid integer)) s LEFT JOIN pg_database d ON (((s.datid)::oid OPERATOR(pg_catalog.=) d.oid)))
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT 1 FROM (multi_router_planner.authors_reference r JOIN (SELECT intermediate_result.datid FROM read_intermediate_result('XXX_2'::text, 'binary'::citus_copy_format) intermediate_result(datid integer)) num_db ON ((r.id OPERATOR(pg_catalog.=) num_db.datid))) LIMIT 1
DEBUG: Creating router plan
?column?
---------------------------------------------------------------------
(0 rows)
-- with a CTE in a view
WITH cte AS MATERIALIZED (SELECT * FROM num_db)
SELECT 1 FROM authors_reference r JOIN cte ON (r.id = cte.datid) LIMIT 1;
DEBUG: found no worker with all shard placements
DEBUG: generating subplan XXX_1 for CTE cte: SELECT datid FROM (SELECT s.datid FROM (multi_router_planner.number1() s(datid) LEFT JOIN pg_database d ON (((s.datid)::oid OPERATOR(pg_catalog.=) d.oid)))) num_db
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT 1 FROM (multi_router_planner.authors_reference r JOIN (SELECT intermediate_result.datid FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(datid integer)) cte ON ((r.id OPERATOR(pg_catalog.=) cte.datid))) LIMIT 1
DEBUG: Creating router plan
?column?
---------------------------------------------------------------------
(0 rows)
-- hide changes between major versions
RESET client_min_messages;
-- with pg_stat_activity view
WITH pg_stat_activity AS MATERIALIZED(
SELECT
pg_stat_activity.datid,
pg_stat_activity.application_name,
pg_stat_activity.query
FROM pg_catalog.pg_stat_activity
)
SELECT 1 FROM authors_reference r LEFT JOIN pg_stat_activity ON (r.id = pg_stat_activity.datid) LIMIT 1;
?column?
---------------------------------------------------------------------
(0 rows)
SET client_min_messages TO DEBUG2;
-- CTEs with where false
-- terse because distribution column inference varies between pg11 & pg12
\set VERBOSITY terse
RESET client_min_messages;
WITH id_author AS MATERIALIZED ( SELECT id, author_id FROM articles_hash WHERE author_id = 1),
id_title AS MATERIALIZED (SELECT id, title from articles_hash WHERE author_id = 1 and 1=0)
SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id;
id | author_id | id | title
---------------------------------------------------------------------
(0 rows)
WITH id_author AS MATERIALIZED ( SELECT id, author_id FROM articles_hash WHERE author_id = 1),
id_title AS MATERIALIZED (SELECT id, title from articles_hash WHERE author_id = 1)
SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id and 1=0;
id | author_id | id | title
---------------------------------------------------------------------
(0 rows)
SET client_min_messages TO DEBUG2;
\set VERBOSITY DEFAULT
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 1 and manager_id = 0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id AND
ce.company_id = 1))
SELECT * FROM hierarchy WHERE LEVEL <= 2 and 1=0;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
company_id | employee_id | manager_id | level
---------------------------------------------------------------------
(0 rows)
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 1 and manager_id = 0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id AND
ce.company_id = 1 AND 1=0))
SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
company_id | employee_id | manager_id | level
---------------------------------------------------------------------
1 | 1 | 0 | 1
(1 row)
WITH RECURSIVE hierarchy as MATERIALIZED (
SELECT *, 1 AS level
FROM company_employees
WHERE company_id = 1 and manager_id = 0 AND 1=0
UNION
SELECT ce.*, (h.level+1)
FROM hierarchy h JOIN company_employees ce
ON (h.employee_id = ce.manager_id AND
h.company_id = ce.company_id AND
ce.company_id = 1))
SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
company_id | employee_id | manager_id | level
---------------------------------------------------------------------
(0 rows)
-- window functions with where false
SELECT word_count, rank() OVER (PARTITION BY author_id ORDER BY word_count)
FROM articles_hash
WHERE author_id = 1 and 1=0;
DEBUG: Creating router plan
word_count | rank
---------------------------------------------------------------------
(0 rows)
-- function calls in WHERE clause with non-relational arguments
SELECT author_id FROM articles_hash
WHERE
substring('hello world', 1, 5) = 'hello'
ORDER BY
author_id
LIMIT 1;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: push down of limit count: 1
author_id
---------------------------------------------------------------------
1
(1 row)
-- when expression evaluates to false
SELECT author_id FROM articles_hash
WHERE
substring('hello world', 1, 4) = 'hello'
ORDER BY
author_id
LIMIT 1;
DEBUG: Creating router plan
author_id
---------------------------------------------------------------------
(0 rows)
-- verify range partitioned tables can be used in router plannable queries
-- just 4 shards to be created for each table to make sure
-- they are 'co-located' pairwise
SET citus.shard_replication_factor TO 1;
SELECT create_distributed_table('authors_range', 'id', 'range');
create_distributed_table
---------------------------------------------------------------------
(1 row)
SELECT create_distributed_table('articles_range', 'author_id', 'range');
create_distributed_table
---------------------------------------------------------------------
(1 row)
SELECT master_create_empty_shard('authors_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 1, shardmaxvalue=10 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('authors_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 11, shardmaxvalue=20 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('authors_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 21, shardmaxvalue=30 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('authors_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 31, shardmaxvalue=40 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('articles_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 1, shardmaxvalue=10 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('articles_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 11, shardmaxvalue=20 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('articles_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 21, shardmaxvalue=30 WHERE shardid = :shard_id;
SELECT master_create_empty_shard('articles_range') as shard_id \gset
UPDATE pg_dist_shard SET shardminvalue = 31, shardmaxvalue=40 WHERE shardid = :shard_id;
SET citus.log_remote_commands TO on;
-- single shard select queries are router plannable
SELECT * FROM articles_range where author_id = 1;
DEBUG: Creating router plan
NOTICE: issuing SELECT id, author_id, title, word_count FROM multi_router_planner.articles_range_840012 articles_range WHERE (author_id OPERATOR(pg_catalog.=) 1)
DETAIL: on server postgres@localhost:xxxxx connectionId: xxxxxxx
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
SELECT * FROM articles_range where author_id = 1 or author_id = 5;
DEBUG: Creating router plan
NOTICE: issuing SELECT id, author_id, title, word_count FROM multi_router_planner.articles_range_840012 articles_range WHERE ((author_id OPERATOR(pg_catalog.=) 1) OR (author_id OPERATOR(pg_catalog.=) 5))
DETAIL: on server postgres@localhost:xxxxx connectionId: xxxxxxx
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- zero shard select query is router plannable
SELECT * FROM articles_range where author_id = 1 and author_id = 2;
DEBUG: Creating router plan
NOTICE: executing the command locally: SELECT id, author_id, title, word_count FROM (SELECT NULL::bigint AS id, NULL::bigint AS author_id, NULL::character varying(20) AS title, NULL::integer AS word_count WHERE false) articles_range(id, author_id, title, word_count) WHERE ((author_id OPERATOR(pg_catalog.=) 1) AND (author_id OPERATOR(pg_catalog.=) 2))
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
-- single shard joins on range partitioned table are router plannable
SELECT * FROM articles_range ar join authors_range au on (ar.author_id = au.id)
WHERE ar.author_id = 1;
DEBUG: Creating router plan
NOTICE: issuing SELECT ar.id, ar.author_id, ar.title, ar.word_count, au.name, au.id FROM (multi_router_planner.articles_range_840012 ar JOIN multi_router_planner.authors_range_840008 au ON ((ar.author_id OPERATOR(pg_catalog.=) au.id))) WHERE (ar.author_id OPERATOR(pg_catalog.=) 1)
DETAIL: on server postgres@localhost:xxxxx connectionId: xxxxxxx
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- zero shard join is router plannable
SELECT * FROM articles_range ar join authors_range au on (ar.author_id = au.id)
WHERE ar.author_id = 1 and au.id = 2;
DEBUG: Creating router plan
NOTICE: executing the command locally: SELECT ar.id, ar.author_id, ar.title, ar.word_count, au.name, au.id FROM ((SELECT NULL::bigint AS id, NULL::bigint AS author_id, NULL::character varying(20) AS title, NULL::integer AS word_count WHERE false) ar(id, author_id, title, word_count) JOIN (SELECT NULL::character varying(20) AS name, NULL::bigint AS id WHERE false) au(name, id) ON ((ar.author_id OPERATOR(pg_catalog.=) au.id))) WHERE ((ar.author_id OPERATOR(pg_catalog.=) 1) AND (au.id OPERATOR(pg_catalog.=) 2))
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
RESET citus.log_remote_commands;
-- This query was intended to test "multi-shard join is not router plannable"
-- To run it using repartition join logic we change the join columns
SET citus.enable_repartition_joins to ON;
SELECT * FROM articles_range ar join authors_range au on (ar.title = au.name)
WHERE ar.author_id = 35;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: join prunable for task partitionId 0 and 1
DEBUG: join prunable for task partitionId 0 and 2
DEBUG: join prunable for task partitionId 0 and 3
DEBUG: join prunable for task partitionId 1 and 0
DEBUG: join prunable for task partitionId 1 and 2
DEBUG: join prunable for task partitionId 1 and 3
DEBUG: join prunable for task partitionId 2 and 0
DEBUG: join prunable for task partitionId 2 and 1
DEBUG: join prunable for task partitionId 2 and 3
DEBUG: join prunable for task partitionId 3 and 0
DEBUG: join prunable for task partitionId 3 and 1
DEBUG: join prunable for task partitionId 3 and 2
DEBUG: pruning merge fetch taskId 1
DETAIL: Creating dependency on merge taskId 2
DEBUG: pruning merge fetch taskId 2
DETAIL: Creating dependency on merge taskId 5
DEBUG: pruning merge fetch taskId 4
DETAIL: Creating dependency on merge taskId 4
DEBUG: pruning merge fetch taskId 5
DETAIL: Creating dependency on merge taskId 10
DEBUG: pruning merge fetch taskId 7
DETAIL: Creating dependency on merge taskId 6
DEBUG: pruning merge fetch taskId 8
DETAIL: Creating dependency on merge taskId 15
DEBUG: pruning merge fetch taskId 10
DETAIL: Creating dependency on merge taskId 8
DEBUG: pruning merge fetch taskId 11
DETAIL: Creating dependency on merge taskId 20
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- This query was intended to test "this is a bug, it is a single shard join
-- query but not router plannable". To run it using repartition join logic we
-- change the join columns.
SELECT * FROM articles_range ar join authors_range au on (ar.title = au.name)
WHERE ar.author_id = 1 or au.id = 5;
DEBUG: Router planner cannot handle multi-shard select queries
DEBUG: join prunable for task partitionId 0 and 1
DEBUG: join prunable for task partitionId 0 and 2
DEBUG: join prunable for task partitionId 0 and 3
DEBUG: join prunable for task partitionId 1 and 0
DEBUG: join prunable for task partitionId 1 and 2
DEBUG: join prunable for task partitionId 1 and 3
DEBUG: join prunable for task partitionId 2 and 0
DEBUG: join prunable for task partitionId 2 and 1
DEBUG: join prunable for task partitionId 2 and 3
DEBUG: join prunable for task partitionId 3 and 0
DEBUG: join prunable for task partitionId 3 and 1
DEBUG: join prunable for task partitionId 3 and 2
DEBUG: pruning merge fetch taskId 1
DETAIL: Creating dependency on merge taskId 5
DEBUG: pruning merge fetch taskId 2
DETAIL: Creating dependency on merge taskId 5
DEBUG: pruning merge fetch taskId 4
DETAIL: Creating dependency on merge taskId 10
DEBUG: pruning merge fetch taskId 5
DETAIL: Creating dependency on merge taskId 10
DEBUG: pruning merge fetch taskId 7
DETAIL: Creating dependency on merge taskId 15
DEBUG: pruning merge fetch taskId 8
DETAIL: Creating dependency on merge taskId 15
DEBUG: pruning merge fetch taskId 10
DETAIL: Creating dependency on merge taskId 20
DEBUG: pruning merge fetch taskId 11
DETAIL: Creating dependency on merge taskId 20
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- bogus query, join on non-partition column, but router plannable due to filters
SELECT * FROM articles_range ar join authors_range au on (ar.id = au.id)
WHERE ar.author_id = 1 and au.id < 10;
DEBUG: Creating router plan
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- join between hash and range partition tables are router plannable
-- only if both tables pruned down to single shard and co-located on the same
-- node.
SET citus.enable_non_colocated_router_query_pushdown TO ON;
-- router plannable when citus.enable_non_colocated_router_query_pushdown is on
SELECT * FROM articles_hash ar join authors_range au on (ar.author_id = au.id)
WHERE ar.author_id = 2 ORDER BY 1,2,3,4,5,6;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 2
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
SET citus.enable_non_colocated_router_query_pushdown TO OFF;
-- not router plannable otherwise
SELECT * FROM articles_hash ar join authors_range au on (ar.author_id = au.id)
WHERE ar.author_id = 2 ORDER BY 1,2,3,4,5,6;
DEBUG: router planner does not support queries that reference non-colocated distributed tables
DEBUG: join prunable for task partitionId 0 and 1
DEBUG: join prunable for task partitionId 0 and 2
DEBUG: join prunable for task partitionId 0 and 3
DEBUG: join prunable for task partitionId 1 and 0
DEBUG: join prunable for task partitionId 1 and 2
DEBUG: join prunable for task partitionId 1 and 3
DEBUG: join prunable for task partitionId 2 and 0
DEBUG: join prunable for task partitionId 2 and 1
DEBUG: join prunable for task partitionId 2 and 3
DEBUG: join prunable for task partitionId 3 and 0
DEBUG: join prunable for task partitionId 3 and 1
DEBUG: join prunable for task partitionId 3 and 2
DEBUG: pruning merge fetch taskId 1
DETAIL: Creating dependency on merge taskId 2
DEBUG: pruning merge fetch taskId 2
DETAIL: Creating dependency on merge taskId 5
DEBUG: pruning merge fetch taskId 4
DETAIL: Creating dependency on merge taskId 4
DEBUG: pruning merge fetch taskId 5
DETAIL: Creating dependency on merge taskId 10
DEBUG: pruning merge fetch taskId 7
DETAIL: Creating dependency on merge taskId 6
DEBUG: pruning merge fetch taskId 8
DETAIL: Creating dependency on merge taskId 15
DEBUG: pruning merge fetch taskId 10
DETAIL: Creating dependency on merge taskId 8
DEBUG: pruning merge fetch taskId 11
DETAIL: Creating dependency on merge taskId 20
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
RESET citus.enable_non_colocated_router_query_pushdown;
-- not router plannable
SELECT * FROM articles_hash ar join authors_range au on (ar.author_id = au.id)
WHERE ar.author_id = 3;
DEBUG: found no worker with all shard placements
DEBUG: join prunable for task partitionId 0 and 1
DEBUG: join prunable for task partitionId 0 and 2
DEBUG: join prunable for task partitionId 0 and 3
DEBUG: join prunable for task partitionId 1 and 0
DEBUG: join prunable for task partitionId 1 and 2
DEBUG: join prunable for task partitionId 1 and 3
DEBUG: join prunable for task partitionId 2 and 0
DEBUG: join prunable for task partitionId 2 and 1
DEBUG: join prunable for task partitionId 2 and 3
DEBUG: join prunable for task partitionId 3 and 0
DEBUG: join prunable for task partitionId 3 and 1
DEBUG: join prunable for task partitionId 3 and 2
DEBUG: pruning merge fetch taskId 1
DETAIL: Creating dependency on merge taskId 2
DEBUG: pruning merge fetch taskId 2
DETAIL: Creating dependency on merge taskId 5
DEBUG: pruning merge fetch taskId 4
DETAIL: Creating dependency on merge taskId 4
DEBUG: pruning merge fetch taskId 5
DETAIL: Creating dependency on merge taskId 10
DEBUG: pruning merge fetch taskId 7
DETAIL: Creating dependency on merge taskId 6
DEBUG: pruning merge fetch taskId 8
DETAIL: Creating dependency on merge taskId 15
DEBUG: pruning merge fetch taskId 10
DETAIL: Creating dependency on merge taskId 8
DEBUG: pruning merge fetch taskId 11
DETAIL: Creating dependency on merge taskId 20
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- join between a range partitioned table and reference table is router plannable
SELECT * FROM articles_range ar join authors_reference au on (ar.author_id = au.id)
WHERE ar.author_id = 1;
DEBUG: Creating router plan
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- still hits a single shard and router plannable
SELECT * FROM articles_range ar join authors_reference au on (ar.author_id = au.id)
WHERE ar.author_id = 1 or ar.author_id = 5;
DEBUG: Creating router plan
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- it is not router plannable if hit multiple shards
SELECT * FROM articles_range ar join authors_reference au on (ar.author_id = au.id)
WHERE ar.author_id = 1 or ar.author_id = 15;
DEBUG: Router planner cannot handle multi-shard select queries
id | author_id | title | word_count | name | id
---------------------------------------------------------------------
(0 rows)
-- following is a bug, function should have been
-- evaluated at master before going to worker
-- need to use a append distributed table here
SELECT create_distributed_table('articles_append', 'author_id', 'append');
create_distributed_table
---------------------------------------------------------------------
(1 row)
SET citus.shard_replication_factor TO 1;
SELECT master_create_empty_shard('articles_append') AS shard_id \gset
UPDATE pg_dist_shard SET shardmaxvalue = 100, shardminvalue=1 WHERE shardid = :shard_id;
-- we execute the query within a function to consolidate the error messages
-- between different executors
CREATE FUNCTION raise_failed_execution_router(query text) RETURNS void AS $$
BEGIN
EXECUTE query;
EXCEPTION WHEN OTHERS THEN
IF SQLERRM LIKE '%failed to execute task%' THEN
RAISE 'Task failed to execute';
ELSIF SQLERRM LIKE '%does not exist%' THEN
RAISE 'Task failed to execute';
ELSIF SQLERRM LIKE '%could not receive query results%' THEN
RAISE 'Task failed to execute';
END IF;
END;
$$LANGUAGE plpgsql;
DEBUG: switching to sequential query execution mode
DETAIL: A command for a distributed function is run. To make sure subsequent commands see the function correctly we need to make sure to use only one connection for all future commands
SET client_min_messages TO ERROR;
\set VERBOSITY terse
SELECT raise_failed_execution_router($$
SELECT author_id FROM articles_append
WHERE
substring('articles_append'::regclass::text, 1, 5) = 'hello'
ORDER BY
author_id
LIMIT 1;
$$);
ERROR: Task failed to execute
-- same query with where false but evaluation left to worker
SELECT raise_failed_execution_router($$
SELECT author_id FROM articles_append
WHERE
substring('articles_append'::regclass::text, 1, 4) = 'hello'
ORDER BY
author_id
LIMIT 1;
$$);
ERROR: Task failed to execute
-- hash-distributed tables can be evaluated on workers since they are synced
SELECT raise_failed_execution_router($$
SELECT author_id FROM articles_single_shard_hash
WHERE
substring('articles_single_shard_hash'::regclass::text, 1, 4) = 'hello'
ORDER BY
author_id
LIMIT 1;
$$);
raise_failed_execution_router
---------------------------------------------------------------------
(1 row)
SELECT raise_failed_execution_router($$
SELECT author_id FROM articles_hash
WHERE
author_id = 1
AND substring('articles_hash'::regclass::text, 1, 5) = 'hello'
ORDER BY
author_id
LIMIT 1;
$$);
raise_failed_execution_router
---------------------------------------------------------------------
(1 row)
-- create a dummy function to be used in filtering
CREATE OR REPLACE FUNCTION someDummyFunction(regclass)
RETURNS text AS
$$
BEGIN
RETURN md5($1::text);
END;
$$ LANGUAGE 'plpgsql' IMMUTABLE;
-- not router plannable, returns all rows
SELECT * FROM articles_hash
WHERE
someDummyFunction('articles_hash') = md5('articles_hash')
ORDER BY
author_id, id
LIMIT 5;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- router plannable, errors
SELECT raise_failed_execution_router($$
SELECT * FROM articles_hash
WHERE
someDummyFunction('articles_hash') = md5('articles_hash') AND author_id = 1
ORDER BY
author_id, id
LIMIT 5;
$$);
raise_failed_execution_router
---------------------------------------------------------------------
(1 row)
\set VERBOSITY DEFAULT
-- temporarily turn off debug messages before dropping the function
SET client_min_messages TO 'NOTICE';
DROP FUNCTION someDummyFunction(regclass);
SET client_min_messages TO 'DEBUG2';
-- complex query hitting a single shard
SELECT
count(DISTINCT CASE
WHEN
word_count > 100
THEN
id
ELSE
NULL
END) as c
FROM
articles_hash
WHERE
author_id = 5;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 5
c
---------------------------------------------------------------------
5
(1 row)
-- same query is not router plannable if hits multiple shards
SELECT
count(DISTINCT CASE
WHEN
word_count > 100
THEN
id
ELSE
NULL
END) as c
FROM
articles_hash
GROUP BY
author_id
ORDER BY c;
DEBUG: Router planner cannot handle multi-shard select queries
c
---------------------------------------------------------------------
4
5
5
5
5
5
5
5
5
5
(10 rows)
-- queries inside transactions can be router plannable
BEGIN;
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
END;
-- queries inside read-only transactions can be router plannable
BEGIN;
SET TRANSACTION READ ONLY;
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
END;
-- cursor queries are router plannable
BEGIN;
DECLARE test_cursor CURSOR FOR
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
FETCH test_cursor;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
(1 row)
FETCH ALL test_cursor;
id | author_id | title | word_count
---------------------------------------------------------------------
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(4 rows)
FETCH test_cursor; -- fetch one row after the last
id | author_id | title | word_count
---------------------------------------------------------------------
(0 rows)
FETCH BACKWARD test_cursor;
id | author_id | title | word_count
---------------------------------------------------------------------
41 | 1 | aznavour | 11814
(1 row)
END;
-- queries inside copy can be router plannable
COPY (
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id) TO STDOUT;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
1 1 arsenous 9572
11 1 alamo 1347
21 1 arcading 5890
31 1 athwartships 7271
41 1 aznavour 11814
-- table creation queries inside can be router plannable
CREATE TEMP TABLE temp_articles_hash as
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY id;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
-- router plannable queries may include filter for aggregates
SELECT count(*), count(*) FILTER (WHERE id < 3)
FROM articles_hash
WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
count | count
---------------------------------------------------------------------
5 | 1
(1 row)
-- non-router plannable queries also support filters
SELECT count(*), count(*) FILTER (WHERE id < 3)
FROM articles_hash
WHERE author_id = 1 or author_id = 2;
DEBUG: Router planner cannot handle multi-shard select queries
count | count
---------------------------------------------------------------------
10 | 2
(1 row)
-- prepare queries can be router plannable
PREPARE author_1_articles as
SELECT *
FROM articles_hash
WHERE author_id = 1
ORDER BY 1;
EXECUTE author_1_articles;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- parametric prepare queries can be router plannable
PREPARE author_articles(int) as
SELECT *
FROM articles_hash
WHERE author_id = $1
ORDER BY 1;
EXECUTE author_articles(1);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
-- queries inside plpgsql functions could be router plannable
CREATE OR REPLACE FUNCTION author_articles_max_id() RETURNS int AS $$
DECLARE
max_id integer;
BEGIN
SELECT MAX(id) FROM articles_hash ah
WHERE author_id = 1
into max_id;
return max_id;
END;
$$ LANGUAGE plpgsql;
DEBUG: switching to sequential query execution mode
DETAIL: A command for a distributed function is run. To make sure subsequent commands see the function correctly we need to make sure to use only one connection for all future commands
SELECT author_articles_max_id();
DEBUG: function does not have co-located tables
DEBUG: Creating router plan
CONTEXT: SQL statement "SELECT MAX(id) FROM articles_hash ah
WHERE author_id = 1"
PL/pgSQL function author_articles_max_id() line XX at SQL statement
DEBUG: query has a single distribution column value: 1
CONTEXT: SQL statement "SELECT MAX(id) FROM articles_hash ah
WHERE author_id = 1"
PL/pgSQL function author_articles_max_id() line XX at SQL statement
author_articles_max_id
---------------------------------------------------------------------
41
(1 row)
-- check that function returning setof query are router plannable
CREATE OR REPLACE FUNCTION author_articles_id_word_count() RETURNS TABLE(id bigint, word_count int) AS $$
DECLARE
BEGIN
RETURN QUERY
SELECT ah.id, ah.word_count
FROM articles_hash ah
WHERE author_id = 1;
END;
$$ LANGUAGE plpgsql;
DEBUG: switching to sequential query execution mode
DETAIL: A command for a distributed function is run. To make sure subsequent commands see the function correctly we need to make sure to use only one connection for all future commands
SELECT * FROM author_articles_id_word_count() ORDER BY 1;
DEBUG: function does not have co-located tables
DEBUG: Creating router plan
CONTEXT: SQL statement "SELECT ah.id, ah.word_count
FROM articles_hash ah
WHERE author_id = 1"
PL/pgSQL function author_articles_id_word_count() line XX at RETURN QUERY
DEBUG: query has a single distribution column value: 1
CONTEXT: SQL statement "SELECT ah.id, ah.word_count
FROM articles_hash ah
WHERE author_id = 1"
PL/pgSQL function author_articles_id_word_count() line XX at RETURN QUERY
id | word_count
---------------------------------------------------------------------
1 | 9572
11 | 1347
21 | 5890
31 | 7271
41 | 11814
(5 rows)
-- materialized views can be created for router plannable queries
CREATE MATERIALIZED VIEW mv_articles_hash_empty AS
SELECT * FROM articles_hash WHERE author_id = 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
SELECT * FROM mv_articles_hash_empty;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
11 | 1 | alamo | 1347
21 | 1 | arcading | 5890
31 | 1 | athwartships | 7271
41 | 1 | aznavour | 11814
(5 rows)
CREATE MATERIALIZED VIEW mv_articles_hash_data AS
SELECT * FROM articles_hash WHERE author_id in (1,2);
DEBUG: Router planner cannot handle multi-shard select queries
SELECT * FROM mv_articles_hash_data ORDER BY 1, 2, 3, 4;
id | author_id | title | word_count
---------------------------------------------------------------------
1 | 1 | arsenous | 9572
2 | 2 | abducing | 13642
11 | 1 | alamo | 1347
12 | 2 | archiblast | 18185
21 | 1 | arcading | 5890
22 | 2 | antipope | 2728
31 | 1 | athwartships | 7271
32 | 2 | amazon | 11342
41 | 1 | aznavour | 11814
42 | 2 | ausable | 15885
(10 rows)
SELECT id
FROM articles_hash
WHERE author_id = 1
ORDER BY 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id
---------------------------------------------------------------------
1
11
21
31
41
(5 rows)
INSERT INTO articles_hash VALUES (51, 1, 'amateus', 1814), (52, 1, 'second amateus', 2824);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
-- verify insert is successful (not router plannable and executable)
SELECT id
FROM articles_hash
WHERE author_id = 1
ORDER BY 1;
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
id
---------------------------------------------------------------------
1
11
21
31
41
51
52
(7 rows)
SET client_min_messages to 'NOTICE';
-- test that a connection failure marks placements invalid
SET citus.shard_replication_factor TO 2;
CREATE TABLE failure_test (a int, b int);
SELECT create_distributed_table('failure_test', 'a', 'hash');
create_distributed_table
---------------------------------------------------------------------
(1 row)
SET citus.enable_ddl_propagation TO off;
CREATE USER router_user;
GRANT USAGE ON SCHEMA multi_router_planner TO router_user;
GRANT INSERT ON ALL TABLES IN SCHEMA multi_router_planner TO router_user;
\c - - - :worker_1_port
SET citus.enable_ddl_propagation TO off;
CREATE USER router_user;
GRANT USAGE ON SCHEMA multi_router_planner TO router_user;
GRANT INSERT ON ALL TABLES IN SCHEMA multi_router_planner TO router_user;
\c - router_user - :master_port
SET search_path TO multi_router_planner;
-- we will fail to connect to worker 2, since the user does not exist
-- still, we never mark placements inactive. Instead, fail the transaction
BEGIN;
INSERT INTO failure_test VALUES (1, 1);
ERROR: connection to the remote node localhost:xxxxx failed with the following error: FATAL: role "router_user" does not exist
ROLLBACK;
INSERT INTO failure_test VALUES (2, 1);
ERROR: connection to the remote node localhost:xxxxx failed with the following error: FATAL: role "router_user" does not exist
SELECT shardid, shardstate, nodename, nodeport FROM pg_dist_shard_placement
WHERE shardid IN (
SELECT shardid FROM pg_dist_shard
WHERE logicalrelid = 'failure_test'::regclass
)
ORDER BY shardid, nodeport;
shardid | shardstate | nodename | nodeport
---------------------------------------------------------------------
840017 | 1 | localhost | 57637
840017 | 1 | localhost | 57638
840018 | 1 | localhost | 57637
840018 | 1 | localhost | 57638
840019 | 1 | localhost | 57637
840019 | 1 | localhost | 57638
840020 | 1 | localhost | 57637
840020 | 1 | localhost | 57638
(8 rows)
\c - postgres - :worker_1_port
DROP OWNED BY router_user;
DROP USER router_user;
\c - - - :master_port
DROP OWNED BY router_user;
DROP USER router_user;
SET search_path TO multi_router_planner;
SET citus.next_shard_id TO 850000;
SET citus.shard_replication_factor TO 1;
CREATE TABLE single_shard_dist(a int, b int);
SELECT create_distributed_table('single_shard_dist', 'a', shard_count=>1);
create_distributed_table
---------------------------------------------------------------------
(1 row)
SET citus.shard_replication_factor TO 2;
CREATE TABLE table_with_four_shards(a int, b int);
SELECT create_distributed_table('table_with_four_shards', 'a', shard_count=>4);
create_distributed_table
---------------------------------------------------------------------
(1 row)
SET client_min_messages TO DEBUG2;
-- Make sure that router rejects planning this query because
-- the target shards are not placed on the same node when
-- citus.enable_non_colocated_router_query_pushdown is disabled.
-- Otherwise, it throws a somewhat meaningless error but we assume
-- that the user is aware of the setting.
SET citus.enable_non_colocated_router_query_pushdown TO ON;
WITH cte AS (
DELETE FROM table_with_four_shards WHERE a = 1 RETURNING *
)
SELECT * FROM single_shard_dist WHERE b IN (SELECT b FROM cte);
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
ERROR: relation "multi_router_planner.single_shard_dist_850000" does not exist
CONTEXT: while executing command on localhost:xxxxx
SET citus.enable_non_colocated_router_query_pushdown TO OFF;
WITH cte AS (
DELETE FROM table_with_four_shards WHERE a = 1 RETURNING *
)
SELECT * FROM single_shard_dist WHERE b IN (SELECT b FROM cte);
DEBUG: router planner does not support queries that reference non-colocated distributed tables
DEBUG: generating subplan XXX_1 for CTE cte: DELETE FROM multi_router_planner.table_with_four_shards WHERE (a OPERATOR(pg_catalog.=) 1) RETURNING a, b
DEBUG: Distributed planning for a fast-path router query
DEBUG: Creating router plan
DEBUG: query has a single distribution column value: 1
DEBUG: Plan XXX query after replacing subqueries and CTEs: SELECT a, b FROM multi_router_planner.single_shard_dist WHERE (b OPERATOR(pg_catalog.=) ANY (SELECT cte.b FROM (SELECT intermediate_result.a, intermediate_result.b FROM read_intermediate_result('XXX_1'::text, 'binary'::citus_copy_format) intermediate_result(a integer, b integer)) cte))
DEBUG: Creating router plan
a | b
---------------------------------------------------------------------
(0 rows)
RESET citus.enable_non_colocated_router_query_pushdown;
SET client_min_messages TO WARNING;
DROP SCHEMA multi_router_planner CASCADE;