Thread: pgsql: Fix EXPLAIN ANALYZE of hash join when the leader doesn'tpartici
Fix EXPLAIN ANALYZE of hash join when the leader doesn't participate. If a hash join appears in a parallel query, there may be no hash table available for explain.c to inspect even though a hash table may have been built in other processes. This could happen either because parallel_leader_participation was set to off or because the leader happened to hit the end of the outer relation immediately (even though the complete relation is not empty) and decided not to build the hash table. Commit bf11e7ee introduced a way for workers to exchange instrumentation via the DSM segment for Sort nodes even though they are not parallel-aware. This commit does the same for Hash nodes, so that explain.c has a way to find instrumentation data from an arbitrary participant that actually built the hash table. Author: Thomas Munro Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAEepm%3D3DUQC2-z252N55eOcZBer6DPdM%3DFzrxH9dZc5vYLsjaA%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/5bcf389ecfd40daf92238e1abbff4fc4d3f18b33 Modified Files -------------- src/backend/commands/explain.c | 60 +++++++++++++++------ src/backend/executor/execParallel.c | 43 +++++++++++---- src/backend/executor/execProcnode.c | 3 ++ src/backend/executor/nodeHash.c | 104 ++++++++++++++++++++++++++++++++++++ src/include/executor/nodeHash.h | 9 ++++ src/include/nodes/execnodes.h | 26 +++++++++ src/test/regress/expected/join.out | 15 ++++++ src/test/regress/sql/join.sql | 11 ++++ 8 files changed, 245 insertions(+), 26 deletions(-)