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, 4 insertions, 0 deletions

diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index 653ddc976ba..09a7404267c 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -108,6 +108,9 @@ typedef bool (*amproperty_function) (Oid index_oid, int attno,
 									 IndexAMProperty prop, const char *propname,
 									 bool *res, bool *isnull);
 
+/* name of phase as used in progress reporting */
+typedef char *(*ambuildphasename_function) (int64 phasenum);
+
 /* validate definition of an opclass for this AM */
 typedef bool (*amvalidate_function) (Oid opclassoid);
 
@@ -213,6 +216,7 @@ typedef struct IndexAmRoutine
 	amcostestimate_function amcostestimate;
 	amoptions_function amoptions;
 	amproperty_function amproperty; /* can be NULL */
+	ambuildphasename_function ambuildphasename;	/* can be NULL */
 	amvalidate_function amvalidate;
 	ambeginscan_function ambeginscan;
 	amrescan_function amrescan;