From: Andres Freund <andres@anarazel.de>
Date: Wed, 19 Dec 2018 20:52:18 +0000 (-0800)
Subject: tableam: Add function to determine newest xid among tuples.
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=415cc80ca6e22144fd5ba4b936071b27e06a3830;p=users%2Fandresfreund%2Fpostgres.git

tableam: Add function to determine newest xid among tuples.

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:
---

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index d6de803396..fec649b842 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -2316,6 +2316,7 @@ static const TableAmRoutine heapam_methods = {
 	.begin_index_fetch = heapam_begin_index_fetch,
 	.reset_index_fetch = heapam_reset_index_fetch,
 	.end_index_fetch = heapam_end_index_fetch,
+	.compute_xid_horizon_for_tuples = heap_compute_xid_horizon_for_tuples,
 
 	.tuple_insert = heapam_heap_insert,
 	.tuple_insert_speculative = heapam_heap_insert_speculative,
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 0b263aaf77..f4a527b126 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -302,7 +302,7 @@ index_compute_xid_horizon_for_tuples(Relation irel,
 
 	/* determine the actual xid horizon */
 	latestRemovedXid =
-		heap_compute_xid_horizon_for_tuples(hrel, htids, nitems);
+		table_compute_xid_horizon_for_tuples(hrel, htids, nitems);
 
 	pfree(htids);
 
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index b7db9fa473..d0240d46f7 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -113,6 +113,15 @@ typedef struct TableAmRoutine
 	void		(*reset_index_fetch) (struct IndexFetchTableData *data);
 	void		(*end_index_fetch) (struct IndexFetchTableData *data);
 
+	/*
+	 * Compute the newest xid among the tuples pointed to by items. This is
+	 * used to compute what snapshots to conflict with when replaying WAL
+	 * records for page-level index vacuums.
+	 */
+	TransactionId (*compute_xid_horizon_for_tuples) (Relation rel,
+													 ItemPointerData *items,
+													 int nitems);
+
 
 	/* ------------------------------------------------------------------------
 	 * Manipulations of physical tuples.
@@ -443,6 +452,14 @@ table_end_index_fetch_table(struct IndexFetchTableData *scan)
  * ----------------------------------------------------------------------------
  */
 
+static inline TransactionId
+table_compute_xid_horizon_for_tuples(Relation rel,
+									 ItemPointerData *items,
+									 int nitems)
+{
+	return rel->rd_tableam->compute_xid_horizon_for_tuples(rel, items, nitems);
+}
+
 /*
  * Insert a tuple from a slot into table AM routine
  */