Propagate sort instrumentation from workers back to leader.

Up until now, when parallel query was used, no details about the
sort method or space used by the workers were available; details
were shown only for any sorting done by the leader.  Fix that.

Commit 1177ab1dabf72bafee8f19d904cee3a299f25892 forced the test case
added by commit 1f6d515a67ec98194c23a5db25660856c9aab944 to run
without parallelism; now that we have this infrastructure, allow
that again, with a little tweaking to make it pass with and without
force_parallel_mode.

Robert Haas and Tom Lane

Discussion: http://postgr.es/m/CA+Tgmoa2VBZW6S8AAXfhpHczb=Rf6RqQ2br+zJvEgwJ0uoD_tQ@mail.gmail.com

1 files changed, 43 insertions, 13 deletions

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 59cd28e595f..17e1b6860ba 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -3227,13 +3227,10 @@ tuplesort_restorepos(Tuplesortstate *state)
  *
  * This can be called after tuplesort_performsort() finishes to obtain
  * printable summary information about how the sort was performed.
- * spaceUsed is measured in kilobytes.
  */
 void
 tuplesort_get_stats(Tuplesortstate *state,
-					const char **sortMethod,
-					const char **spaceType,
-					long *spaceUsed)
+					TuplesortInstrumentation *stats)
 {
 	/*
 	 * Note: it might seem we should provide both memory and disk usage for a
@@ -3246,35 +3243,68 @@ tuplesort_get_stats(Tuplesortstate *state,
 	 */
 	if (state->tapeset)
 	{
-		*spaceType = "Disk";
-		*spaceUsed = LogicalTapeSetBlocks(state->tapeset) * (BLCKSZ / 1024);
+		stats->spaceType = SORT_SPACE_TYPE_DISK;
+		stats->spaceUsed = LogicalTapeSetBlocks(state->tapeset) * (BLCKSZ / 1024);
 	}
 	else
 	{
-		*spaceType = "Memory";
-		*spaceUsed = (state->allowedMem - state->availMem + 1023) / 1024;
+		stats->spaceType = SORT_SPACE_TYPE_MEMORY;
+		stats->spaceUsed = (state->allowedMem - state->availMem + 1023) / 1024;
 	}
 
 	switch (state->status)
 	{
 		case TSS_SORTEDINMEM:
 			if (state->boundUsed)
-				*sortMethod = "top-N heapsort";
+				stats->sortMethod = SORT_TYPE_TOP_N_HEAPSORT;
 			else
-				*sortMethod = "quicksort";
+				stats->sortMethod = SORT_TYPE_QUICKSORT;
 			break;
 		case TSS_SORTEDONTAPE:
-			*sortMethod = "external sort";
+			stats->sortMethod = SORT_TYPE_EXTERNAL_SORT;
 			break;
 		case TSS_FINALMERGE:
-			*sortMethod = "external merge";
+			stats->sortMethod = SORT_TYPE_EXTERNAL_MERGE;
 			break;
 		default:
-			*sortMethod = "still in progress";
+			stats->sortMethod = SORT_TYPE_STILL_IN_PROGRESS;
 			break;
 	}
 }
 
+/*
+ * Convert TuplesortMethod to a string.
+ */
+const char *
+tuplesort_method_name(TuplesortMethod m)
+{
+	switch (m)
+	{
+		case SORT_TYPE_STILL_IN_PROGRESS:
+			return "still in progress";
+		case SORT_TYPE_TOP_N_HEAPSORT:
+			return "top-N heapsort";
+		case SORT_TYPE_QUICKSORT:
+			return "quicksort";
+		case SORT_TYPE_EXTERNAL_SORT:
+			return "external sort";
+		case SORT_TYPE_EXTERNAL_MERGE:
+			return "external merge";
+	}
+
+	return "unknown";
+}
+
+/*
+ * Convert TuplesortSpaceType to a string.
+ */
+const char *
+tuplesort_space_type_name(TuplesortSpaceType t)
+{
+	Assert(t == SORT_SPACE_TYPE_DISK || t == SORT_SPACE_TYPE_MEMORY);
+	return t == SORT_SPACE_TYPE_DISK ? "Disk" : "Memory";
+}
+
 
 /*
  * Heap manipulation routines, per Knuth's Algorithm 5.2.3H.