From 1ca6d596a776c850406f338052066b4e0e6a8493 Mon Sep 17 00:00:00 2001 From: Tomas Vondra Date: Wed, 1 Apr 2026 20:21:36 +0200 Subject: [PATCH v7 6/6] fixup: show prefetch stats for TidRangeScan --- src/backend/commands/explain.c | 3 - src/backend/executor/execParallel.c | 18 ++--- src/backend/executor/nodeTidrangescan.c | 94 ++++++++++++++++++------- 3 files changed, 77 insertions(+), 38 deletions(-) diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 99b64d87126..4491270b387 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -4120,9 +4120,6 @@ show_scan_io_usage(ScanState *planstate, ExplainState *es) SharedTidRangeScanInstrumentation *sinstrument = ((TidRangeScanState *) planstate)->trss_sinstrument; - /* collect prefetch statistics from the read stream */ - stats = planstate->ss_currentScanDesc->rs_instrument->io; - /* get the sum of the counters set within each and every process */ if (sinstrument) { diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c index 3bb5b0d1cd2..9edd27da2e6 100644 --- a/src/backend/executor/execParallel.c +++ b/src/backend/executor/execParallel.c @@ -275,9 +275,9 @@ ExecParallelEstimate(PlanState *planstate, ExecParallelEstimateContext *e) e->pcxt); break; case T_TidRangeScanState: - if (planstate->plan->parallel_aware) - ExecTidRangeScanEstimate((TidRangeScanState *) planstate, - e->pcxt); + /* even when not parallel-aware, for EXPLAIN ANALYZE */ + ExecTidRangeScanEstimate((TidRangeScanState *) planstate, + e->pcxt); break; case T_AppendState: if (planstate->plan->parallel_aware) @@ -507,9 +507,9 @@ ExecParallelInitializeDSM(PlanState *planstate, d->pcxt); break; case T_TidRangeScanState: - if (planstate->plan->parallel_aware) - ExecTidRangeScanInitializeDSM((TidRangeScanState *) planstate, - d->pcxt); + /* even when not parallel-aware, for EXPLAIN ANALYZE */ + ExecTidRangeScanInitializeDSM((TidRangeScanState *) planstate, + d->pcxt); break; case T_AppendState: if (planstate->plan->parallel_aware) @@ -1392,9 +1392,9 @@ ExecParallelInitializeWorker(PlanState *planstate, ParallelWorkerContext *pwcxt) pwcxt); break; case T_TidRangeScanState: - if (planstate->plan->parallel_aware) - ExecTidRangeScanInitializeWorker((TidRangeScanState *) planstate, - pwcxt); + /* even when not parallel-aware, for EXPLAIN ANALYZE */ + ExecTidRangeScanInitializeWorker((TidRangeScanState *) planstate, + pwcxt); break; case T_AppendState: if (planstate->plan->parallel_aware) diff --git a/src/backend/executor/nodeTidrangescan.c b/src/backend/executor/nodeTidrangescan.c index 9b6e2b91183..7126538addc 100644 --- a/src/backend/executor/nodeTidrangescan.c +++ b/src/backend/executor/nodeTidrangescan.c @@ -471,6 +471,14 @@ ExecTidRangeScanEstimate(TidRangeScanState *node, ParallelContext *pcxt) { EState *estate = node->ss.ps.state; Size size; + bool instrument = node->ss.ps.instrument != NULL; + bool parallel_aware = node->ss.ps.plan->parallel_aware; + + if (!instrument && !parallel_aware) + { + /* No DSM required by the scan */ + return; + } size = table_parallelscan_estimate(node->ss.ss_currentRelation, estate->es_snapshot); @@ -480,7 +488,7 @@ ExecTidRangeScanEstimate(TidRangeScanState *node, ParallelContext *pcxt) size = MAXALIGN(size); /* account for instrumentation, if required */ - if (node->ss.ps.instrument && pcxt->nworkers > 0) + if (instrument && pcxt->nworkers > 0) { size = add_size(size, offsetof(SharedTidRangeScanInstrumentation, sinstrument)); size = add_size(size, mul_size(pcxt->nworkers, sizeof(TidRangeScanInstrumentation))); @@ -502,15 +510,16 @@ ExecTidRangeScanInitializeDSM(TidRangeScanState *node, ParallelContext *pcxt) EState *estate = node->ss.ps.state; ParallelTableScanDesc pscan; SharedTidRangeScanInstrumentation *sinstrument = NULL; + bool instrument = node->ss.ps.instrument != NULL; + bool parallel_aware = node->ss.ps.plan->parallel_aware; Size size; - char *ptr; uint32 flags = SO_NONE; - if (ScanRelIsReadOnly(&node->ss)) - flags |= SO_HINT_REL_READ_ONLY; - - if (estate->es_instrument) - flags |= SO_SCAN_INSTRUMENT; + if (!instrument && !parallel_aware) + { + /* No DSM required by the scan */ + return; + } size = MAXALIGN(node->trss_pscanlen); if (node->ss.ps.instrument && pcxt->nworkers > 0) @@ -525,26 +534,41 @@ ExecTidRangeScanInitializeDSM(TidRangeScanState *node, ParallelContext *pcxt) pscan, estate->es_snapshot); shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, pscan); - node->ss.ss_currentScanDesc = - table_beginscan_parallel_tidrange(node->ss.ss_currentRelation, - pscan, flags); /* initialize the shared instrumentation (with correct alignment) */ - ptr = (char *) pscan; - ptr += MAXALIGN(node->trss_pscanlen); - if (node->ss.ps.instrument && pcxt->nworkers > 0) + if (instrument && pcxt->nworkers > 0) + { + /* initialize the shared instrumentation (with correct alignment) */ + char *ptr = (char *) pscan; + + ptr += MAXALIGN(node->trss_pscanlen); + sinstrument = (SharedTidRangeScanInstrumentation *) ptr; - if (sinstrument) - { sinstrument->num_workers = pcxt->nworkers; /* ensure any unfilled slots will contain zeroes */ memset(sinstrument->sinstrument, 0, pcxt->nworkers * sizeof(TidRangeScanInstrumentation)); + + node->trss_sinstrument = sinstrument; } - node->trss_sinstrument = sinstrument; + if (!parallel_aware) + { + /* Only here to set up worker node's shared instrumentation */ + return; + } + + if (ScanRelIsReadOnly(&node->ss)) + flags |= SO_HINT_REL_READ_ONLY; + + if (estate->es_instrument) + flags |= SO_SCAN_INSTRUMENT; + + node->ss.ss_currentScanDesc = + table_beginscan_parallel_tidrange(node->ss.ss_currentRelation, + pscan, flags); } /* ---------------------------------------------------------------- @@ -573,28 +597,46 @@ void ExecTidRangeScanInitializeWorker(TidRangeScanState *node, ParallelWorkerContext *pwcxt) { - EState *estate = node->ss.ps.state; ParallelTableScanDesc pscan; - char *ptr; + EState *estate = node->ss.ps.state; + bool instrument = node->ss.ps.instrument != NULL; + bool parallel_aware = node->ss.ps.plan->parallel_aware; uint32 flags = SO_NONE; + if (!instrument && !parallel_aware) + { + /* No DSM required by the scan */ + return; + } + + pscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); + + /* set pointer to the shared instrumentation */ + if (instrument) + { + /* set pointer to the shared instrumentation */ + char *ptr = (char *) pscan; + ptr += MAXALIGN(pscan->phs_len); + + node->trss_sinstrument = (SharedTidRangeScanInstrumentation *) ptr; + } + + if (!parallel_aware) + { + /* Only here to set up worker node's SharedInfo */ + return; + } + if (ScanRelIsReadOnly(&node->ss)) flags |= SO_HINT_REL_READ_ONLY; if (estate->es_instrument) flags |= SO_SCAN_INSTRUMENT; - pscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); + /* XXX only start the scan for parallel-aware ones */ node->ss.ss_currentScanDesc = table_beginscan_parallel_tidrange(node->ss.ss_currentRelation, pscan, flags); - - /* set pointer to the shared instrumentation */ - ptr = (char *) pscan; - ptr += MAXALIGN(pscan->phs_len); - - if (node->ss.ps.instrument) - node->trss_sinstrument = (SharedTidRangeScanInstrumentation *) ptr; } /* ---------------------------------------------------------------- -- 2.53.0