SET search_path TO arbitrary_configs_router; SET client_min_messages TO WARNING; -- test simple select for a single row SELECT * FROM articles_hash WHERE author_id = 10 AND id = 50; -- get all titles by a single author SELECT title FROM articles_hash WHERE author_id = 10; -- try ordering them by word count SELECT title, word_count FROM articles_hash WHERE author_id = 10 ORDER BY word_count DESC NULLS LAST; -- look at last two articles by an author SELECT title, id FROM articles_hash WHERE author_id = 5 ORDER BY id LIMIT 2; -- find all articles by two authors in same shard -- but plan is not fast path router plannable due to -- two distribution columns in the query SELECT title, author_id FROM articles_hash WHERE author_id = 7 OR author_id = 8 ORDER BY author_id ASC, id; -- having clause is supported if it goes to a single shard -- and single dist. key on the query 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; -- fast path planner only support = operator SELECT * FROM articles_hash WHERE author_id <= 1; SELECT * FROM articles_hash WHERE author_id IN (1, 3) ORDER BY 1,2,3,4; -- queries with CTEs cannot go through fast-path planning WITH first_author AS ( SELECT id FROM articles_hash WHERE author_id = 1) SELECT * FROM first_author; -- two CTE joins also cannot go through fast-path planning WITH id_author AS ( SELECT id, author_id FROM articles_hash WHERE author_id = 1), id_title AS (SELECT id, title from articles_hash WHERE author_id = 1) SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id; -- this is a different case where each CTE is recursively planned and those goes -- through the fast-path router planner, but the top level join is not WITH id_author AS ( SELECT id, author_id FROM articles_hash WHERE author_id = 1), id_title AS (SELECT id, title from articles_hash WHERE author_id = 2) SELECT * FROM id_author, id_title WHERE id_author.id = id_title.id; -- recursive CTEs are also cannot go through fast -- path planning WITH RECURSIVE hierarchy as ( 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; WITH update_article AS ( UPDATE articles_hash SET word_count = 10 WHERE id = 1 AND word_count = 9 RETURNING * ) SELECT * FROM update_article; WITH delete_article AS ( DELETE FROM articles_hash WHERE id = 1 AND word_count = 10 RETURNING * ) SELECT * FROM delete_article; -- grouping sets are supported via fast-path SELECT id, substring(title, 2, 1) AS subtitle, count(*) FROM articles_hash WHERE author_id = 1 GROUP BY GROUPING SETS ((id),(subtitle)) ORDER BY id, subtitle; -- queries which involve functions in FROM clause are not supported via fast path planning SELECT * FROM articles_hash, position('om' in 'Thomas') WHERE author_id = 1; -- sublinks are not supported via fast path planning SELECT * FROM articles_hash WHERE author_id IN (SELECT author_id FROM articles_hash WHERE author_id = 2) ORDER BY articles_hash.id; -- subqueries are not supported via fast path planning 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; 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; -- simple lookup query just works SELECT * FROM articles_hash WHERE author_id = 1; -- below query hits a single shard but with multiple filters -- so cannot go via fast-path SELECT * FROM articles_hash WHERE author_id = 1 OR author_id = 17; -- rename the output columns SELECT id as article_id, word_count * id as random_value FROM articles_hash WHERE author_id = 1; -- joins do not go through fast-path planning 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; -- single shard select with limit goes through fast-path planning SELECT * FROM articles_hash WHERE author_id = 1 LIMIT 3; -- single shard select with limit + offset goes through fast-path planning SELECT * FROM articles_hash WHERE author_id = 1 LIMIT 2 OFFSET 1; -- single shard select with limit + offset + order by goes through fast-path planning SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id desc LIMIT 2 OFFSET 1; -- single shard select with group by on non-partition column goes through fast-path planning SELECT id FROM articles_hash WHERE author_id = 1 GROUP BY id ORDER BY id; -- single shard select with distinct goes through fast-path planning SELECT DISTINCT id FROM articles_hash WHERE author_id = 1 ORDER BY id; -- single shard aggregate goes through fast-path planning SELECT avg(word_count) FROM articles_hash WHERE author_id = 2; -- max, min, sum, count goes through fast-path planning 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; -- queries with aggregates and group by goes through fast-path planning SELECT max(word_count) FROM articles_hash WHERE author_id = 1 GROUP BY author_id; -- set operations are not supported via fast-path planning SELECT * FROM ( SELECT * FROM articles_hash WHERE author_id = 1 UNION SELECT * FROM articles_hash WHERE author_id = 3 ) AS combination ORDER BY id; -- function calls in the target list is supported via fast path SELECT LEFT(title, 1) FROM articles_hash WHERE author_id = 1; -- top-level union queries are supported through recursive planning -- unions in subqueries are not supported via fast-path planning SELECT * FROM ( (SELECT * FROM articles_hash WHERE author_id = 1) UNION (SELECT * FROM articles_hash WHERE author_id = 1)) uu ORDER BY 1, 2 LIMIT 5; -- Test various filtering options for router plannable check -- cannot go through fast-path if there is -- explicit coercion SELECT * FROM articles_hash WHERE author_id = 1::bigint; -- can go through fast-path if there is -- implicit coercion -- This doesn't work see the related issue -- reported https://github.com/citusdata/citus/issues/2605 -- SELECT * -- FROM articles_hash -- WHERE author_id = 1.0; SELECT * FROM articles_hash WHERE author_id = 68719476736; -- this is bigint -- cannot go through fast-path due to -- multiple filters on the dist. key SELECT * FROM articles_hash WHERE author_id = 1 and author_id >= 1; -- cannot go through fast-path due to -- multiple filters on the dist. key SELECT * FROM articles_hash WHERE author_id = 1 or id = 1; -- goes through fast-path planning because -- the dist. key is ANDed with the rest of the -- filters SELECT * FROM articles_hash WHERE author_id = 1 and (id = 1 or id = 41); -- this time there is an OR clause which prevents -- router planning at all SELECT * FROM articles_hash WHERE author_id = 1 and id = 1 or id = 41; -- goes through fast-path planning because -- the dist. key is ANDed with the rest of the -- filters SELECT * FROM articles_hash WHERE author_id = 1 and (id = random()::int * 0); -- not router plannable due to function call on the right side SELECT * FROM articles_hash WHERE author_id = (random()::int * 0 + 1); -- Citus does not qualify this as a fast-path because -- dist_key = func() SELECT * FROM articles_hash WHERE author_id = abs(-1); -- Citus does not qualify this as a fast-path because -- dist_key = func() SELECT * FROM articles_hash WHERE 1 = abs(author_id); -- Citus does not qualify this as a fast-path because -- dist_key = func() SELECT * FROM articles_hash WHERE author_id = abs(author_id - 2); -- the function is not on the dist. key, so qualify as -- fast-path SELECT * FROM articles_hash WHERE author_id = 1 and (id = abs(id - 2)); -- not router plannable due to is true SELECT * FROM articles_hash WHERE (author_id = 1) is true; -- router plannable, (boolean expression) = true is collapsed to (boolean expression) SELECT * FROM articles_hash WHERE (author_id = 1) = true; -- some more complex quals SELECT count(*) FROM articles_hash WHERE (author_id = 15) AND (id = 1 OR word_count > 5); SELECT count(*) FROM articles_hash WHERE (author_id = 15) OR (id = 1 AND word_count > 5); SELECT count(*) FROM articles_hash WHERE (id = 15) OR (author_id = 1 AND word_count > 5); SELECT count(*) FROM articles_hash WHERE (id = 15) AND (author_id = 1 OR word_count > 5); SELECT count(*) FROM articles_hash WHERE (id = 15) AND (author_id = 1 AND (word_count > 5 OR id = 2)); SELECT count(*) FROM articles_hash WHERE (id = 15) AND (title ilike 'a%' AND (word_count > 5 OR author_id = 2)); SELECT count(*) FROM articles_hash WHERE (id = 15) AND (title ilike 'a%' AND (word_count > 5 AND author_id = 2)); SELECT count(*) FROM articles_hash WHERE (id = 15) AND (title ilike 'a%' AND ((word_count > 5 OR title ilike 'b%' ) AND (author_id = 2 AND word_count > 50))); -- fast-path router plannable, between operator is on another column SELECT * FROM articles_hash WHERE (author_id = 1) and id between 0 and 20; -- fast-path 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'; -- fast-path router plannable, order is changed SELECT * FROM articles_hash WHERE (id = 1 or id = 31) and title like '%s' and (author_id = 1); -- fast-path router plannable SELECT * FROM articles_hash WHERE (title like '%s' or title like 'a%') and (author_id = 1); -- fast-path 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); -- window functions are supported with fast-path router plannable SELECT LAG(title, 1) over (ORDER BY word_count) prev, title, word_count FROM articles_hash WHERE author_id = 5; 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; SELECT id, MIN(id) over (order by word_count) FROM articles_hash WHERE author_id = 1; SELECT id, word_count, AVG(word_count) over (order by word_count) FROM articles_hash WHERE author_id = 1; SELECT word_count, rank() OVER (PARTITION BY author_id ORDER BY word_count) FROM articles_hash WHERE author_id = 1; -- some more tests on complex target lists SELECT DISTINCT ON (author_id, id) author_id, id, MIN(id) over (order by avg(word_count)) * AVG(id * 5.2 + (1.0/max(word_count))) over (order by max(word_count)) as t1, count(*) FILTER (WHERE title LIKE 'al%') as cnt_with_filter, count(*) FILTER (WHERE '0300030' LIKE '%3%') as cnt_with_filter_2, avg(case when id > 2 then char_length(word_count::text) * (id * strpos(word_count::text, '1')) end) as case_cnt, COALESCE(strpos(avg(word_count)::text, '1'), 20) FROM articles_hash as aliased_table WHERE author_id = 1 GROUP BY author_id, id HAVING count(DISTINCT title) > 0 ORDER BY author_id, id, sum(word_count) - avg(char_length(title)) DESC, COALESCE(array_upper(ARRAY[max(id)],1) * 5,0) DESC; -- where false queries are router plannable but not fast-path SELECT * FROM articles_hash WHERE false; -- fast-path with false SELECT * FROM articles_hash WHERE author_id = 1 and false; -- fast-path with false SELECT * FROM articles_hash WHERE author_id = 1 and 1=0; SELECT * FROM articles_hash WHERE null and author_id = 1; -- we cannot qualify dist_key = X operator Y via -- fast-path planning SELECT * FROM articles_hash WHERE author_id = 1 + 1; -- where false with immutable function returning false -- goes through fast-path SELECT * FROM articles_hash a WHERE a.author_id = 10 and int4eq(1, 2); -- partition_column is null clause does not prune out any shards, -- all shards remain after shard pruning, not router plannable -- not fast-path router either SELECT * FROM articles_hash a WHERE a.author_id is null; -- partition_column equals to null clause prunes out all shards -- no shards after shard pruning, router plannable -- not fast-path router either SELECT * FROM articles_hash a WHERE a.author_id = null; -- union/difference /intersection with where false -- this query was not originally router plannable, addition of 1=0 -- makes it router plannable but not fast-path 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; -- same with the above, but with WHERE false SELECT * FROM ( SELECT * FROM articles_hash WHERE author_id = 1 UNION SELECT * FROM articles_hash WHERE author_id = 2 and 1=0 ) AS combination WHERE false ORDER BY id; -- 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; -- complex query hitting a single shard and a fast-path SELECT count(DISTINCT CASE WHEN word_count > 100 THEN id ELSE NULL END) as c FROM articles_hash WHERE author_id = 5; -- queries inside transactions can be fast-path router plannable BEGIN; SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id; END; -- queries inside read-only transactions can be fast-path router plannable SET TRANSACTION READ ONLY; SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id; END; -- cursor queries are fast-path router plannable BEGIN; DECLARE test_cursor CURSOR FOR SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id; FETCH test_cursor; FETCH ALL test_cursor; FETCH test_cursor; -- fetch one row after the last FETCH BACKWARD test_cursor; END; -- queries inside copy can be router plannable COPY ( SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id) TO STDOUT; -- table creation queries inside can be fast-path router plannable CREATE TEMP TABLE temp_articles_hash as SELECT * FROM articles_hash WHERE author_id = 1 ORDER BY id; -- fast-path router plannable queries may include filter for aggregates SELECT count(*), count(*) FILTER (WHERE id < 3) FROM articles_hash WHERE author_id = 1; -- prepare queries can be router plannable PREPARE author_1_articles as SELECT * FROM articles_hash WHERE author_id = 1; EXECUTE author_1_articles; EXECUTE author_1_articles; EXECUTE author_1_articles; EXECUTE author_1_articles; EXECUTE author_1_articles; EXECUTE author_1_articles; -- parametric prepare queries can be router plannable PREPARE author_articles(int) as SELECT * FROM articles_hash WHERE author_id = $1; EXECUTE author_articles(1); EXECUTE author_articles(1); EXECUTE author_articles(1); EXECUTE author_articles(1); EXECUTE author_articles(1); EXECUTE author_articles(1); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); EXECUTE author_articles(NULL); PREPARE author_articles_update(int) AS UPDATE articles_hash SET title = 'test' WHERE author_id = $1; EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); EXECUTE author_articles_update(NULL); -- we don't want too many details. though we're omitting -- "DETAIL: distribution column value:", we see it acceptable -- since the query results verifies the correctness \set VERBOSITY terse SELECT author_articles_max_id(); SELECT author_articles_max_id(); SELECT author_articles_max_id(); SELECT author_articles_max_id(); SELECT author_articles_max_id(); SELECT author_articles_max_id(); SELECT author_articles_max_id(1); SELECT author_articles_max_id(1); SELECT author_articles_max_id(1); SELECT author_articles_max_id(1); SELECT author_articles_max_id(1); SELECT author_articles_max_id(1); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(); SELECT * FROM author_articles_id_word_count(1); SELECT * FROM author_articles_id_word_count(1); SELECT * FROM author_articles_id_word_count(1); SELECT * FROM author_articles_id_word_count(1); SELECT * FROM author_articles_id_word_count(1); SELECT * FROM author_articles_id_word_count(1); \set VERBOSITY default -- insert .. select via coordinator could also -- use fast-path queries PREPARE insert_sel(int, int) AS INSERT INTO articles_hash SELECT * FROM articles_hash WHERE author_id = $2 AND word_count = $1 OFFSET 0; EXECUTE insert_sel(1,1); EXECUTE insert_sel(1,1); EXECUTE insert_sel(1,1); EXECUTE insert_sel(1,1); EXECUTE insert_sel(1,1); EXECUTE insert_sel(1,1); -- one final interesting preperad statement -- where one of the filters is on the target list PREPARE fast_path_agg_filter(int, int) AS SELECT count(*) FILTER (WHERE word_count=$1) FROM articles_hash WHERE author_id = $2; EXECUTE fast_path_agg_filter(1,1); EXECUTE fast_path_agg_filter(2,2); EXECUTE fast_path_agg_filter(3,3); EXECUTE fast_path_agg_filter(4,4); EXECUTE fast_path_agg_filter(5,5); EXECUTE fast_path_agg_filter(6,6); -- views internally become subqueries, so not fast-path router query SELECT * FROM test_view; -- materialized views can be created for fast-path router plannable queries CREATE MATERIALIZED VIEW mv_articles_hash_empty AS SELECT * FROM articles_hash WHERE author_id = 1; SELECT * FROM mv_articles_hash_empty; SELECT id FROM articles_hash WHERE author_id = 1; INSERT INTO articles_hash VALUES (51, 1, 'amateus', 1814), (52, 1, 'second amateus', 2824); -- verify insert is successfull (not router plannable and executable) SELECT id FROM articles_hash WHERE author_id = 1; SELECT count(*) FROM collections_list WHERE key = 4; SELECT count(*) FROM collections_list_1 WHERE key = 4; SELECT count(*) FROM collections_list_2 WHERE key = 4; UPDATE collections_list SET value = 15 WHERE key = 4; SELECT count(*) FILTER (where value = 15) FROM collections_list WHERE key = 4; SELECT count(*) FILTER (where value = 15) FROM collections_list_1 WHERE key = 4; SELECT count(*) FILTER (where value = 15) FROM collections_list_2 WHERE key = 4; -- test INSERT using values from generate_series() and repeat() functions INSERT INTO authors_reference (id, name) VALUES (generate_series(1, 10), repeat('Migjeni', 3)); SELECT * FROM authors_reference ORDER BY 1, 2;