Revert "Fix accumulation of parallel worker instrumentation."

This reverts commit 2c09a5c12a66087218c7f8cba269cd3de51b9b82.  Per
further discussion, that doesn't seem to be the best possible fix.

Discussion: http://postgr.es/m/CAA4eK1LW2aFKzY3=vwvc=t-juzPPVWP2uT1bpx_MeyEqnM+p8g@mail.gmail.com

1 files changed, 13 insertions, 38 deletions

diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 558cb08b07e..d57cdbd4e15 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -819,19 +819,6 @@ ExecParallelReinitialize(PlanState *planstate,
 	/* Old workers must already be shut down */
 	Assert(pei->finished);
 
-	/* Clear the instrumentation space from the last round. */
-	if (pei->instrumentation)
-	{
-		Instrumentation *instrument;
-		SharedExecutorInstrumentation *sh_instr;
-		int			i;
-
-		sh_instr = pei->instrumentation;
-		instrument = GetInstrumentationArray(sh_instr);
-		for (i = 0; i < sh_instr->num_workers * sh_instr->num_plan_nodes; ++i)
-			InstrInit(&instrument[i], pei->planstate->state->es_instrument);
-	}
-
 	/* Force parameters we're going to pass to workers to be evaluated. */
 	ExecEvalParamExecParams(sendParams, estate);
 
@@ -953,33 +940,21 @@ ExecParallelRetrieveInstrumentation(PlanState *planstate,
 	for (n = 0; n < instrumentation->num_workers; ++n)
 		InstrAggNode(planstate->instrument, &instrument[n]);
 
-	if (!planstate->worker_instrument)
-	{
-		/*
-		 * Allocate space for the per-worker detail.
-		 *
-		 * Worker instrumentation should be allocated in the same context as
-		 * the regular instrumentation information, which is the per-query
-		 * context. Switch into per-query memory context.
-		 */
-		oldcontext = MemoryContextSwitchTo(planstate->state->es_query_cxt);
-		ibytes =
-			mul_size(instrumentation->num_workers, sizeof(Instrumentation));
-		planstate->worker_instrument =
-			palloc(ibytes + offsetof(WorkerInstrumentation, instrument));
-		MemoryContextSwitchTo(oldcontext);
-
-		for (n = 0; n < instrumentation->num_workers; ++n)
-			InstrInit(&planstate->worker_instrument->instrument[n],
-					  planstate->state->es_instrument);
-	}
+	/*
+	 * Also store the per-worker detail.
+	 *
+	 * Worker instrumentation should be allocated in the same context as the
+	 * regular instrumentation information, which is the per-query context.
+	 * Switch into per-query memory context.
+	 */
+	oldcontext = MemoryContextSwitchTo(planstate->state->es_query_cxt);
+	ibytes = mul_size(instrumentation->num_workers, sizeof(Instrumentation));
+	planstate->worker_instrument =
+		palloc(ibytes + offsetof(WorkerInstrumentation, instrument));
+	MemoryContextSwitchTo(oldcontext);
 
 	planstate->worker_instrument->num_workers = instrumentation->num_workers;
-
-	/* Accumulate the per-worker detail. */
-	for (n = 0; n < instrumentation->num_workers; ++n)
-		InstrAggNode(&planstate->worker_instrument->instrument[n],
-					 &instrument[n]);
+	memcpy(&planstate->worker_instrument->instrument, instrument, ibytes);
 
 	/* Perform any node-type-specific work that needs to be done. */
 	switch (nodeTag(planstate))