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, 31 insertions, 3 deletions

diff --git a/src/include/utils/tuplesort.h b/src/include/utils/tuplesort.h
index 28c168a801..b6b8c8ef8c 100644
--- a/src/include/utils/tuplesort.h
+++ b/src/include/utils/tuplesort.h
@@ -32,6 +32,34 @@
 typedef struct Tuplesortstate Tuplesortstate;
 
 /*
+ * Data structures for reporting sort statistics.  Note that
+ * TuplesortInstrumentation can't contain any pointers because we
+ * sometimes put it in shared memory.
+ */
+typedef enum
+{
+	SORT_TYPE_STILL_IN_PROGRESS = 0,
+	SORT_TYPE_TOP_N_HEAPSORT,
+	SORT_TYPE_QUICKSORT,
+	SORT_TYPE_EXTERNAL_SORT,
+	SORT_TYPE_EXTERNAL_MERGE
+} TuplesortMethod;
+
+typedef enum
+{
+	SORT_SPACE_TYPE_DISK,
+	SORT_SPACE_TYPE_MEMORY
+} TuplesortSpaceType;
+
+typedef struct TuplesortInstrumentation
+{
+	TuplesortMethod sortMethod; /* sort algorithm used */
+	TuplesortSpaceType spaceType;	/* type of space spaceUsed represents */
+	long		spaceUsed;		/* space consumption, in kB */
+} TuplesortInstrumentation;
+
+
+/*
  * We provide multiple interfaces to what is essentially the same code,
  * since different callers have different data to be sorted and want to
  * specify the sort key information differently.  There are two APIs for
@@ -107,9 +135,9 @@ extern bool tuplesort_skiptuples(Tuplesortstate *state, int64 ntuples,
 extern void tuplesort_end(Tuplesortstate *state);
 
 extern void tuplesort_get_stats(Tuplesortstate *state,
-					const char **sortMethod,
-					const char **spaceType,
-					long *spaceUsed);
+					TuplesortInstrumentation *stats);
+extern const char *tuplesort_method_name(TuplesortMethod m);
+extern const char *tuplesort_space_type_name(TuplesortSpaceType t);
 
 extern int	tuplesort_merge_order(int64 allowedMem);