From 43847dd5e93816ef6e37dfb6c8bb7f98f48ddc01 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 9 Mar 2025 13:11:20 -0400 Subject: [PATCH] Don't try to parallelize array_agg() on an anonymous record type. This doesn't work because record_recv requires the typmod that identifies the specific record type (in our session) and array_agg_deserialize has no convenient way to get that information. The result is an "input of anonymous composite types is not implemented" error. We could probably make this work if we had to, but it does not seem worth the trouble, given that it took this long to get a field report. Just shut off parallelization, as though record_recv didn't exist. Oversight in commit 16fd03e95. Back-patch to v16 where that came in. Reported-by: Kirill Zdornyy Diagnosed-by: Richard Guo Author: Tom Lane Reviewed-by: David Rowley Discussion: https://postgr.es/m/atLI5Kce2ie1zcYjU0w_kjtVaxiYbYGTihrkLDmGZQnRDD4pnXukIATaABbnIj9pUnelC4ESvCXMm4HAyHg-v61XABaKpERj0A2IXzJZM7g=@dineserve.com Backpatch-through: 16 --- src/backend/parser/parse_agg.c | 11 ++++++++++- src/test/regress/expected/aggregates.out | 20 +++++++++++++++++++- src/test/regress/sql/aggregates.sql | 9 +++++++-- 3 files changed, 36 insertions(+), 4 deletions(-) diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index b15d9b152ef..be88909da22 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -1961,7 +1961,7 @@ resolve_aggregate_transtype(Oid aggfuncid, /* * agg_args_support_sendreceive - * Returns true if all non-byval of aggref's arg types have send and + * Returns true if all non-byval types of aggref's args have send and * receive functions. */ bool @@ -1976,6 +1976,15 @@ agg_args_support_sendreceive(Aggref *aggref) TargetEntry *tle = (TargetEntry *) lfirst(lc); Oid type = exprType((Node *) tle->expr); + /* + * RECORD is a special case: it has typsend/typreceive functions, but + * record_recv only works if passed the correct typmod to identify the + * specific anonymous record type. array_agg_deserialize cannot do + * that, so we have to disclaim support for the case. + */ + if (type == RECORDOID) + return false; + typeTuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(type)); if (!HeapTupleIsValid(typeTuple)) elog(ERROR, "cache lookup failed for type %u", type); diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out index 1c1ca7573ad..30af83f23cc 100644 --- a/src/test/regress/expected/aggregates.out +++ b/src/test/regress/expected/aggregates.out @@ -2033,8 +2033,8 @@ explain (costs off) select * from v_pagg_test order by y; -> Parallel Seq Scan on pagg_test (13 rows) -set max_parallel_workers_per_gather = 0; -- Ensure results are the same without parallel aggregation. +set max_parallel_workers_per_gather = 0; select * from v_pagg_test order by y; y | tmin | tmax | tndistinct | bmin | bmax | bndistinct | amin | amax | andistinct | aamin | aamax | aandistinct ---+------+------+------------+------+------+------------+------+------+------------+-------+-------+------------- @@ -2050,6 +2050,24 @@ select * from v_pagg_test order by y; 9 | 19 | 4999 | 250 | 1019 | 999 | 250 | 19 | 4999 | 250 | 19 | 4999 | 250 (10 rows) +-- Check that we don't fail on anonymous record types. +set max_parallel_workers_per_gather = 2; +explain (costs off) +select array_dims(array_agg(s)) from (select * from pagg_test) s; + QUERY PLAN +-------------------------------------------- + Aggregate + -> Gather + Workers Planned: 2 + -> Parallel Seq Scan on pagg_test +(4 rows) + +select array_dims(array_agg(s)) from (select * from pagg_test) s; + array_dims +------------ + [1:5000] +(1 row) + -- Clean up reset max_parallel_workers_per_gather; reset bytea_output; diff --git a/src/test/regress/sql/aggregates.sql b/src/test/regress/sql/aggregates.sql index 1a18ca3d8fe..675b23add59 100644 --- a/src/test/regress/sql/aggregates.sql +++ b/src/test/regress/sql/aggregates.sql @@ -805,11 +805,16 @@ select * from v_pagg_test order by y; -- Ensure parallel aggregation is actually being used. explain (costs off) select * from v_pagg_test order by y; -set max_parallel_workers_per_gather = 0; - -- Ensure results are the same without parallel aggregation. +set max_parallel_workers_per_gather = 0; select * from v_pagg_test order by y; +-- Check that we don't fail on anonymous record types. +set max_parallel_workers_per_gather = 2; +explain (costs off) +select array_dims(array_agg(s)) from (select * from pagg_test) s; +select array_dims(array_agg(s)) from (select * from pagg_test) s; + -- Clean up reset max_parallel_workers_per_gather; reset bytea_output;