diff --git a/src/backend/distributed/planner/multi_logical_optimizer.c b/src/backend/distributed/planner/multi_logical_optimizer.c index 76e38237ad6..371ba54e650 100644 --- a/src/backend/distributed/planner/multi_logical_optimizer.c +++ b/src/backend/distributed/planner/multi_logical_optimizer.c @@ -4753,22 +4753,35 @@ WorkerLimitCount(Node *limitCount, Node *limitOffset, OrderByLimitReference if (workerLimitNode != NULL && limitOffset != NULL) { Const *workerLimitConst = (Const *) workerLimitNode; - Const *workerOffsetConst = (Const *) limitOffset; - int64 workerLimitCount = DatumGetInt64(workerLimitConst->constvalue); - int64 workerOffsetCount = DatumGetInt64(workerOffsetConst->constvalue); - workerLimitCount = workerLimitCount + workerOffsetCount; - workerLimitNode = (Node *) MakeIntegerConstInt64(workerLimitCount); + /* Only update the worker limit if the const is not null.*/ + if (!workerLimitConst->constisnull) + { + Const *workerOffsetConst = (Const *) limitOffset; + int64 workerLimitCount = DatumGetInt64(workerLimitConst->constvalue); + + /* If the offset is null, it defaults to 0 when cast to int64. */ + int64 workerOffsetCount = DatumGetInt64(workerOffsetConst->constvalue); + workerLimitCount = workerLimitCount + workerOffsetCount; + workerLimitNode = (Node *) MakeIntegerConstInt64(workerLimitCount); + } } /* display debug message on limit push down */ if (workerLimitNode != NULL) { Const *workerLimitConst = (Const *) workerLimitNode; - int64 workerLimitCount = DatumGetInt64(workerLimitConst->constvalue); + if (!workerLimitConst->constisnull) + { + int64 workerLimitCount = DatumGetInt64(workerLimitConst->constvalue); - ereport(DEBUG1, (errmsg("push down of limit count: " INT64_FORMAT, - workerLimitCount))); + ereport(DEBUG1, (errmsg("push down of limit count: " INT64_FORMAT, + workerLimitCount))); + } + else + { + ereport(DEBUG1, (errmsg("push down of limit count: ALL"))); + } } return workerLimitNode; diff --git a/src/test/regress/expected/multi_limit_clause.out b/src/test/regress/expected/multi_limit_clause.out index 65304b777e8..83cd0583703 100644 --- a/src/test/regress/expected/multi_limit_clause.out +++ b/src/test/regress/expected/multi_limit_clause.out @@ -521,6 +521,86 @@ SELECT 1 | 1 (1 row) +-- check if we can correctly push the limit when it is null +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey LIMIT null; +DEBUG: push down of limit count: ALL + l_orderkey +--------------------------------------------------------------------- + 1 + 1 + 1 + 1 + 1 + 1 + 2 +(7 rows) + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET 1 LIMIT null; +DEBUG: push down of limit count: ALL + l_orderkey +--------------------------------------------------------------------- + 1 + 1 + 1 + 1 + 1 + 2 +(6 rows) + +SELECT count(*) FROM lineitem LIMIT null; +DEBUG: push down of limit count: ALL + count +--------------------------------------------------------------------- + 12000 +(1 row) + +SELECT count(*) FROM lineitem OFFSET 0 LIMIT null; +DEBUG: push down of limit count: ALL + count +--------------------------------------------------------------------- + 12000 +(1 row) + +-- check if we push the right limit when both offset and limit are given +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET 1 LIMIT 3; +DEBUG: push down of limit count: 4 + l_orderkey +--------------------------------------------------------------------- + 1 + 1 + 1 +(3 rows) + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET null LIMIT 1; +DEBUG: push down of limit count: 1 + l_orderkey +--------------------------------------------------------------------- + 1 +(1 row) + +-- check if we can correctly push the limit when it is all +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 LIMIT all; +DEBUG: push down of limit count: ALL + l_orderkey +--------------------------------------------------------------------- + 1 + 1 + 1 + 1 + 1 + 1 +(6 rows) + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 OFFSET 2 LIMIT all; +DEBUG: push down of limit count: ALL + l_orderkey +--------------------------------------------------------------------- + 1 + 1 + 1 + 1 +(4 rows) + SET client_min_messages TO NOTICE; -- non constants should not push down CREATE OR REPLACE FUNCTION my_limit() diff --git a/src/test/regress/sql/multi_limit_clause.sql b/src/test/regress/sql/multi_limit_clause.sql index 8d14bbbc8ed..5e3b3e3deb2 100644 --- a/src/test/regress/sql/multi_limit_clause.sql +++ b/src/test/regress/sql/multi_limit_clause.sql @@ -222,6 +222,25 @@ SELECT ORDER BY 2 DESC, 1 LIMIT 5; +-- check if we can correctly push the limit when it is null +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey LIMIT null; + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET 1 LIMIT null; + +SELECT count(*) FROM lineitem LIMIT null; + +SELECT count(*) FROM lineitem OFFSET 0 LIMIT null; + +-- check if we push the right limit when both offset and limit are given +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET 1 LIMIT 3; + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 3 ORDER BY l_orderkey OFFSET null LIMIT 1; + +-- check if we can correctly push the limit when it is all +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 LIMIT all; + +SELECT l_orderkey FROM lineitem WHERE l_orderkey < 2 OFFSET 2 LIMIT all; + SET client_min_messages TO NOTICE; -- non constants should not push down