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Merge pull request #1074 from citusdata/router_query_hint 

Add hint to errored real time queries
pull/1122/head
Murat Tuncer 2017-01-12 10:56:28 +02:00 committed by GitHub
parent eeee0a7898 cb1dfd0a17
commit dbaf7f0e7e
8 changed files with 139 additions and 75 deletions
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105
src/backend/distributed/planner/multi_logical_planner.c
View File

@ -17,6 +17,7 @@
#include "access/nbtree.h"
#include "catalog/pg_am.h"
#include "commands/defrem.h"
#include "distributed/colocation_utils.h"
#include "distributed/metadata_cache.h"
#include "distributed/multi_logical_optimizer.h"
#include "distributed/multi_logical_planner.h"
@ -57,6 +58,7 @@ static RuleApplyFunction RuleApplyFunctionArray[JOIN_RULE_LAST] = { 0 }; /* join
static MultiNode * MultiPlanTree(Query *queryTree);
static void ErrorIfQueryNotSupported(Query *queryTree);
static bool HasUnsupportedJoinWalker(Node *node, void *context);
static bool ErrorHintRequired(const char *errorHint, Query *queryTree);
static void ErrorIfSubqueryNotSupported(Query *subqueryTree);
static bool HasTablesample(Query *queryTree);
static bool HasOuterJoin(Query *queryTree);
@ -362,95 +364,118 @@ MultiPlanTree(Query *queryTree)
static void
ErrorIfQueryNotSupported(Query *queryTree)
{
char *errorDetail = NULL;
char *errorMessage = NULL;
bool hasTablesample = false;
bool hasUnsupportedJoin = false;
bool hasComplexJoinOrder = false;
bool hasComplexRangeTableType = false;
bool preconditionsSatisfied = true;
const char *errorHint = NULL;
const char *joinHint = "Consider joining tables on partition column and have "
"equal filter on joining columns.";
const char *filterHint = "Consider using an equality filter on the distributed "
"table's partition column.";
if (queryTree->hasSubLinks)
{
preconditionsSatisfied = false;
errorDetail = "Subqueries other than in from-clause are currently unsupported";
errorMessage = "could not run distributed query with subquery outside the "
"FROM clause";
errorHint = filterHint;
}
if (queryTree->hasWindowFuncs)
{
preconditionsSatisfied = false;
errorDetail = "Window functions are currently unsupported";
errorMessage = "could not run distributed query with window functions";
errorHint = filterHint;
}
if (queryTree->setOperations)
{
preconditionsSatisfied = false;
errorDetail = "Union, Intersect, or Except are currently unsupported";
errorMessage = "could not run distributed query with UNION, INTERSECT, or "
"EXCEPT";
errorHint = filterHint;
}
if (queryTree->hasRecursive)
{
preconditionsSatisfied = false;
errorDetail = "Recursive queries are currently unsupported";
errorMessage = "could not run distributed query with RECURSIVE";
errorHint = filterHint;
}
if (queryTree->cteList)
{
preconditionsSatisfied = false;
errorDetail = "Common Table Expressions are currently unsupported";
errorMessage = "could not run distributed query with common table expressions";
errorHint = filterHint;
}
if (queryTree->hasForUpdate)
{
preconditionsSatisfied = false;
errorDetail = "For Update/Share commands are currently unsupported";
errorMessage = "could not run distributed query with FOR UPDATE/SHARE commands";
errorHint = filterHint;
}
if (queryTree->distinctClause)
{
preconditionsSatisfied = false;
errorDetail = "Distinct clause is currently unsupported";
errorMessage = "could not run distributed query with DISTINCT clause";
errorHint = filterHint;
}
if (queryTree->groupingSets)
{
preconditionsSatisfied = false;
errorDetail = "Grouping sets, cube, and rollup is currently unsupported";
errorMessage = "could not run distributed query with GROUPING SETS, CUBE, "
"or ROLLUP";
errorHint = filterHint;
}
hasTablesample = HasTablesample(queryTree);
if (hasTablesample)
{
preconditionsSatisfied = false;
errorDetail = "Tablesample is currently unsupported";
errorMessage = "could not run distributed query which use TABLESAMPLE";
errorHint = filterHint;
}
hasUnsupportedJoin = HasUnsupportedJoinWalker((Node *) queryTree->jointree, NULL);
if (hasUnsupportedJoin)
{
preconditionsSatisfied = false;
errorDetail = "Join types other than inner/outer joins are currently unsupported";
errorMessage = "could not run distributed query with join types other than "
"INNER or OUTER JOINS";
errorHint = joinHint;
}
hasComplexJoinOrder = HasComplexJoinOrder(queryTree);
if (hasComplexJoinOrder)
{
preconditionsSatisfied = false;
errorDetail = "Complex join orders are currently unsupported";
errorMessage = "could not run distributed query with complex join orders";
errorHint = joinHint;
}
hasComplexRangeTableType = HasComplexRangeTableType(queryTree);
if (hasComplexRangeTableType)
{
preconditionsSatisfied = false;
errorDetail = "Complex table expressions are currently unsupported";
errorMessage = "could not run distributed query with complex table expressions";
errorHint = filterHint;
}
/* finally check and error out if not satisfied */
if (!preconditionsSatisfied)
{
bool showHint = ErrorHintRequired(errorHint, queryTree);
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform distributed planning on this query"),
errdetail("%s", errorDetail)));
errmsg("%s", errorMessage),
showHint ? errhint("%s", errorHint) : 0));
}
}
@ -514,6 +539,56 @@ HasUnsupportedJoinWalker(Node *node, void *context)
}
/*
* ErrorHintRequired returns true if error hint shold be displayed with the
* query error message. Error hint is valid only for queries involving reference
* and hash partitioned tables. If more than one hash distributed table is
* present we display the hint only if the tables are colocated. If the query
* only has reference table(s), then it is handled by router planner.
*/
static bool
ErrorHintRequired(const char *errorHint, Query *queryTree)
{
List *rangeTableList = NIL;
ListCell *rangeTableCell = NULL;
List *colocationIdList = NIL;
if (errorHint == NULL)
{
return false;
}
ExtractRangeTableRelationWalker((Node *) queryTree, &rangeTableList);
foreach(rangeTableCell, rangeTableList)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rangeTableCell);
Oid relationId = rte->relid;
char partitionMethod = PartitionMethod(relationId);
if (partitionMethod == DISTRIBUTE_BY_NONE)
{
continue;
}
else if (partitionMethod == DISTRIBUTE_BY_HASH)
{
int colocationId = TableColocationId(relationId);
colocationIdList = list_append_unique_int(colocationIdList, colocationId);
}
else
{
return false;
}
}
/* do not display the hint if there are more than one colocation group */
if (list_length(colocationIdList) > 1)
{
return false;
}
return true;
}
/*
* ErrorIfSubqueryNotSupported checks that we can perform distributed planning for
* the given subquery.

48
src/test/regress/expected/multi_router_planner.out
View File

@ -334,8 +334,8 @@ 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;
DEBUG: predicate pruning for shardId 840001
DEBUG: predicate pruning for shardId 840000
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- recursive CTEs are supported when filtered on partition column
CREATE TABLE company_employees (company_id int, employee_id int, manager_id int);
SELECT master_create_distributed_table('company_employees', 'company_id', 'hash');
@ -416,8 +416,8 @@ SELECT * FROM hierarchy WHERE LEVEL <= 2;
DEBUG: predicate pruning for shardId 840004
DEBUG: predicate pruning for shardId 840005
DEBUG: predicate pruning for shardId 840006
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- logically wrong query, query involves different shards
-- from the same table
WITH RECURSIVE hierarchy as (
@ -437,8 +437,8 @@ DEBUG: predicate pruning for shardId 840006
DEBUG: predicate pruning for shardId 840003
DEBUG: predicate pruning for shardId 840004
DEBUG: predicate pruning for shardId 840005
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- CTE with queries other than SELECT is not supported
WITH new_article AS (
INSERT INTO articles_hash VALUES (1, 1, 'arsenous', 9572) RETURNING *
@ -504,8 +504,8 @@ SELECT
FROM articles_hash
WHERE author_id = 1 or author_id = 2
GROUP BY GROUPING SETS ((id),(subtitle));
ERROR: cannot perform distributed planning on this query
DETAIL: Grouping sets, cube, and rollup is currently unsupported
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: predicate pruning for shardId 840001
@ -540,17 +540,17 @@ DEBUG: Plan is router executable
-- they are not supported if multiple workers are involved
SELECT * FROM articles_hash, position('om' in 'Thomas') WHERE author_id = 1 or author_id = 2;
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- subqueries are not supported in WHERE clause in Citus
SELECT * FROM articles_hash WHERE author_id IN (SELECT id FROM authors_hash WHERE name LIKE '%a');
ERROR: cannot plan queries that include both regular and partitioned relations
SELECT * FROM articles_hash WHERE author_id IN (SELECT author_id FROM articles_hash WHERE author_id = 1 or author_id = 3);
ERROR: cannot perform distributed planning on this query
DETAIL: Join types other than inner/outer joins are currently unsupported
ERROR: could not run distributed query with join types other than INNER or OUTER JOINS
HINT: Consider joining tables on partition column and have equal filter on joining columns.
SELECT * FROM articles_hash WHERE author_id = (SELECT 1);
ERROR: cannot perform distributed planning on this query
DETAIL: Subqueries other than in from-clause are currently unsupported
ERROR: could not run distributed query with subquery outside the FROM clause
HINT: Consider using an equality filter on the distributed table's partition column.
-- 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)
@ -641,8 +641,8 @@ HINT: Set citus.task_executor_type to "task-tracker".
-- 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;
ERROR: cannot perform distributed planning on this query
DETAIL: Subqueries other than in from-clause are currently unsupported
ERROR: could not run distributed query with subquery outside the FROM clause
HINT: Consider using an equality filter on the distributed table's partition column.
-- simple lookup query
SELECT *
FROM articles_hash
@ -748,8 +748,8 @@ SELECT a.author_id as first_author, b.word_count as second_word_count
LIMIT 3;
DEBUG: predicate pruning for shardId 840000
DEBUG: Found no worker with all shard placements
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- single shard select with limit is router plannable
SELECT *
FROM articles_hash
@ -961,8 +961,8 @@ SET client_min_messages to 'NOTICE';
(SELECT * FROM articles_hash WHERE author_id = 1)
UNION
(SELECT * FROM articles_hash WHERE author_id = 2);
ERROR: cannot perform distributed planning on this query
DETAIL: Union, Intersect, or Except are currently unsupported
ERROR: could not run distributed query with UNION, INTERSECT, or EXCEPT
HINT: Consider using an equality filter on the distributed table's partition column.
SELECT * FROM (
(SELECT * FROM articles_hash WHERE author_id = 1)
UNION
@ -1317,13 +1317,13 @@ DEBUG: Plan is router executable
SELECT id, MIN(id) over (order by word_count)
FROM articles_hash
WHERE author_id = 1 or author_id = 2;
ERROR: cannot perform distributed planning on this query
DETAIL: Window functions are currently unsupported
ERROR: could not run distributed query with window functions
HINT: Consider using an equality filter on the distributed table's partition column.
SELECT LAG(title, 1) over (ORDER BY word_count) prev, title, word_count
FROM articles_hash
WHERE author_id = 5 or author_id = 2;
ERROR: cannot perform distributed planning on this query
DETAIL: Window functions are currently unsupported
ERROR: could not run distributed query with window functions
HINT: Consider using an equality filter on the distributed table's partition column.
-- where false queries are router plannable
SELECT *
FROM articles_hash

12
src/test/regress/expected/multi_simple_queries.out
View File

@ -176,16 +176,16 @@ SELECT author_id, sum(word_count) AS corpus_size FROM articles
-- UNION/INTERSECT queries are unsupported if on multiple shards
SELECT * FROM articles WHERE author_id = 10 UNION
SELECT * FROM articles WHERE author_id = 2;
ERROR: cannot perform distributed planning on this query
DETAIL: Union, Intersect, or Except are currently unsupported
ERROR: could not run distributed query with UNION, INTERSECT, or EXCEPT
HINT: Consider using an equality filter on the distributed table's partition column.
-- queries using CTEs are unsupported
WITH long_names AS ( SELECT id FROM authors WHERE char_length(name) > 15 )
SELECT title FROM articles;
ERROR: cannot plan queries that include both regular and partitioned relations
-- queries which involve functions in FROM clause are unsupported.
SELECT * FROM articles, position('om' in 'Thomas');
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
HINT: Consider using an equality filter on the distributed table's partition column.
-- subqueries are not supported in WHERE clause in Citus
SELECT * FROM articles WHERE author_id IN (SELECT id FROM authors WHERE name LIKE '%a');
ERROR: cannot plan queries that include both regular and partitioned relations
@ -250,8 +250,8 @@ ORDER BY articles.id;
-- subqueries are not supported in SELECT clause
SELECT a.title AS name, (SELECT a2.id FROM articles_single_shard a2 WHERE a.id = a2.id LIMIT 1)
AS special_price FROM articles a;
ERROR: cannot perform distributed planning on this query
DETAIL: Subqueries other than in from-clause are currently unsupported
ERROR: could not run distributed query with subquery outside the FROM clause
HINT: Consider using an equality filter on the distributed table's partition column.
-- joins are not supported between local and distributed tables
SELECT title, authors.name FROM authors, articles WHERE authors.id = articles.author_id;
ERROR: cannot plan queries that include both regular and partitioned relations

15
src/test/regress/expected/multi_verify_no_subquery.out
View File

@ -6,18 +6,13 @@
ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 1030000;
SELECT * FROM lineitem WHERE l_orderkey IN
(SELECT l_orderkey FROM lineitem WHERE l_quantity > 0);
ERROR: cannot perform distributed planning on this query
DETAIL: Join types other than inner/outer joins are currently unsupported
ERROR: could not run distributed query with join types other than INNER or OUTER JOINS
SELECT l_quantity FROM lineitem WHERE EXISTS
(SELECT 1 FROM orders WHERE o_orderkey = l_orderkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Join types other than inner/outer joins are currently unsupported
ERROR: could not run distributed query with join types other than INNER or OUTER JOINS
SELECT l_quantity FROM lineitem WHERE l_orderkey IN (SELECT o_orderkey FROM orders);
ERROR: cannot perform distributed planning on this query
DETAIL: Join types other than inner/outer joins are currently unsupported
ERROR: could not run distributed query with join types other than INNER or OUTER JOINS
SELECT l_orderkey FROM lineitem WHERE l_quantity > ALL(SELECT o_orderkey FROM orders);
ERROR: cannot perform distributed planning on this query
DETAIL: Subqueries other than in from-clause are currently unsupported
ERROR: could not run distributed query with subquery outside the FROM clause
SELECT l_quantity FROM lineitem WHERE l_orderkey = (SELECT min(o_orderkey) FROM orders);
ERROR: cannot perform distributed planning on this query
DETAIL: Subqueries other than in from-clause are currently unsupported
ERROR: could not run distributed query with subquery outside the FROM clause

12
src/test/regress/output/multi_outer_join.source
View File

@ -329,8 +329,7 @@ FROM
LEFT JOIN multi_outer_join_right r1 ON (l1.l_custkey = r1.r_custkey)
LEFT JOIN multi_outer_join_right r2 ON (l1.l_custkey = r2.r_custkey)
RIGHT JOIN multi_outer_join_left l2 ON (r2.r_custkey = l2.l_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
-- add an anti-join, this should also error out
SELECT
*
@ -341,8 +340,7 @@ FROM
RIGHT JOIN multi_outer_join_left l2 ON (r2.r_custkey = l2.l_custkey)
WHERE
r1.r_custkey is NULL;
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
-- Three way join 2-2-1 (local + broadcast join) should work
SELECT
l_custkey, r_custkey, t_custkey
@ -387,8 +385,7 @@ FROM
multi_outer_join_left l1
LEFT JOIN multi_outer_join_right r1 ON (l1.l_custkey = r1.r_custkey)
RIGHT JOIN multi_outer_join_third t1 ON (r1.r_custkey = t1.t_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
-- Right join with single shard left most table should work
SELECT
t_custkey, r_custkey, l_custkey
@ -447,8 +444,7 @@ FROM
multi_outer_join_third t1
RIGHT JOIN multi_outer_join_right r1 ON (t1.t_custkey = r1.r_custkey)
RIGHT JOIN multi_outer_join_left l1 ON (r1.r_custkey = l1.l_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
-- full outer join should work with 1-1 matched shards
SELECT
l_custkey, r_custkey

16
src/test/regress/output/multi_outer_join_reference.source
View File

@ -358,8 +358,8 @@ FROM
LEFT JOIN multi_outer_join_right_reference r1 ON (l1.l_custkey = r1.r_custkey)
LEFT JOIN multi_outer_join_right_reference r2 ON (l1.l_custkey = r2.r_custkey)
RIGHT JOIN multi_outer_join_left_hash l2 ON (r2.r_custkey = l2.l_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
HINT: Consider joining tables on partition column and have equal filter on joining columns.
-- add an anti-join, this should also error out
SELECT
*
@ -370,8 +370,8 @@ FROM
RIGHT JOIN multi_outer_join_left_hash l2 ON (r2.r_custkey = l2.l_custkey)
WHERE
r1.r_custkey is NULL;
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
HINT: Consider joining tables on partition column and have equal filter on joining columns.
-- Three way join 2-1-1 (broadcast + broadcast join) should work
SELECT
l_custkey, r_custkey, t_custkey
@ -417,8 +417,8 @@ FROM
multi_outer_join_left_hash l1
LEFT JOIN multi_outer_join_right_hash r1 ON (l1.l_custkey = r1.r_custkey)
RIGHT JOIN multi_outer_join_third_reference t1 ON (r1.r_custkey = t1.t_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
HINT: Consider joining tables on partition column and have equal filter on joining columns.
-- Right join with single shard left most table should work
SELECT
t_custkey, r_custkey, l_custkey
@ -479,8 +479,8 @@ FROM
multi_outer_join_third_reference t1
RIGHT JOIN multi_outer_join_right_hash r1 ON (t1.t_custkey = r1.r_custkey)
RIGHT JOIN multi_outer_join_left_hash l1 ON (r1.r_custkey = l1.l_custkey);
ERROR: cannot perform distributed planning on this query
DETAIL: Complex join orders are currently unsupported
ERROR: could not run distributed query with complex join orders
HINT: Consider joining tables on partition column and have equal filter on joining columns.
-- full outer join should work with 1-1 matched shards
SELECT
l_custkey, r_custkey

3
src/test/regress/output/multi_subquery.source
View File

@ -178,8 +178,7 @@ SELECT count(*) FROM
(SELECT l_orderkey FROM lineitem_subquery) UNION ALL
(SELECT 1::bigint)
) b;
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
-- Check that we error out if queries in union do not include partition columns.
SELECT count(*) FROM
(

3
src/test/regress/output/multi_subquery_0.source
View File

@ -178,8 +178,7 @@ SELECT count(*) FROM
(SELECT l_orderkey FROM lineitem_subquery) UNION ALL
(SELECT 1::bigint)
) b;
ERROR: cannot perform distributed planning on this query
DETAIL: Complex table expressions are currently unsupported
ERROR: could not run distributed query with complex table expressions
-- Check that we error out if queries in union do not include partition columns.
SELECT count(*) FROM
(