From 868e7ca8f660a75949e095cbaa56386e0c4655f2 Mon Sep 17 00:00:00 2001 From: amitlan Date: Sat, 23 Jan 2021 16:35:21 +0900 Subject: [PATCH] Prevent FDW insert batching during cross-partition updates A cross-partition update of a partitioned table is internally implemented as delete+insert. As things stand now, even those inserts inadvertently end up using batching, because ExecInitRoutingInfo() that is in the charge of initialing ri_BatchSize for partitions doesn't check the original operation, which would be CMD_UPDATE. That may pose a problem if the target of such an insert is a foreign partition, because its FDW may not be able to handle both the original update and the batched insert being performed at the same time. For now, prevent batching in such cases. --- contrib/postgres_fdw/postgres_fdw.c | 13 +++++++++++-- src/backend/executor/execPartition.c | 3 ++- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 8648be0b81..a9eeeb87f4 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -1934,17 +1934,26 @@ static int postgresGetForeignModifyBatchSize(ResultRelInfo *resultRelInfo) { int batch_size; + PgFdwModifyState *fmstate = resultRelInfo->ri_FdwState ? + (PgFdwModifyState *) resultRelInfo->ri_FdwState : + NULL; /* should be called only once */ Assert(resultRelInfo->ri_BatchSize == 0); + /* + * Should never get called when the insert is being performed as part of + * a row movement operation. + */ + Assert(fmstate == NULL || fmstate->aux_fmstate == NULL); + /* * In EXPLAIN without ANALYZE, ri_fdwstate is NULL, so we have to lookup * the option directly in server/table options. Otherwise just use the * value we determined earlier. */ - if (resultRelInfo->ri_FdwState) - batch_size = ((PgFdwModifyState *) resultRelInfo->ri_FdwState)->batch_size; + if (fmstate) + batch_size = fmstate->batch_size; else batch_size = get_batch_size_option(resultRelInfo->ri_RelationDesc); diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c index 1746cb8793..882397bc30 100644 --- a/src/backend/executor/execPartition.c +++ b/src/backend/executor/execPartition.c @@ -1000,7 +1000,8 @@ ExecInitRoutingInfo(ModifyTableState *mtstate, * * If the FDW does not support batching, we set the batch size to 1. */ - if (partRelInfo->ri_FdwRoutine != NULL && + if (mtstate->operation == CMD_INSERT && + partRelInfo->ri_FdwRoutine != NULL && partRelInfo->ri_FdwRoutine->GetForeignModifyBatchSize && partRelInfo->ri_FdwRoutine->ExecForeignBatchInsert) partRelInfo->ri_BatchSize = -- 2.24.1