Report progress of CREATE INDEX operations

This uses the progress reporting infrastructure added by c16dc1aca5e0,
adding support for CREATE INDEX and CREATE INDEX CONCURRENTLY.

There are two pieces to this: one is index-AM-agnostic, and the other is
AM-specific.  The latter is fairly elaborate for btrees, including
reportage for parallel index builds and the separate phases that btree
index creation uses; other index AMs, which are much simpler in their
building procedures, have simplistic reporting only, but that seems
sufficient, at least for non-concurrent builds.

The index-AM-agnostic part is fairly complete, providing insight into
the CONCURRENTLY wait phases as well as block-based progress during the
index validation table scan.  (The index validation index scan requires
patching each AM, which has not been included here.)

Reviewers: Rahila Syed, Pavan Deolasee, Tatsuro Yamada
Discussion: https://postgr.es/m/20181220220022.mg63bhk26zdpvmcj@alvherre.pgsql

1 files changed, 23 insertions, 0 deletions

diff --git a/src/backend/utils/adt/amutils.c b/src/backend/utils/adt/amutils.c
index 060ffe501ec..e81d6cc0562 100644
--- a/src/backend/utils/adt/amutils.c
+++ b/src/backend/utils/adt/amutils.c
@@ -445,3 +445,26 @@ pg_index_column_has_property(PG_FUNCTION_ARGS)
 
 	return indexam_property(fcinfo, propname, InvalidOid, relid, attno);
 }
+
+/*
+ * Return the name of the given phase, as used for progress reporting by the
+ * given AM.
+ */
+Datum
+pg_indexam_progress_phasename(PG_FUNCTION_ARGS)
+{
+	Oid			amoid = PG_GETARG_OID(0);
+	int32		phasenum = PG_GETARG_INT32(1);
+	IndexAmRoutine *routine;
+	char	   *name;
+
+	routine = GetIndexAmRoutineByAmId(amoid, true);
+	if (routine == NULL || !routine->ambuildphasename)
+		PG_RETURN_NULL();
+
+	name = routine->ambuildphasename(phasenum);
+	if (!name)
+		PG_RETURN_NULL();
+
+	PG_RETURN_TEXT_P(CStringGetTextDatum(name));
+}