3 files changed, 42 insertions, 3 deletions
diff --git a/src/include/access/gist.h b/src/include/access/gist.h
index 3234f241560..ce8bfd83ea4 100644
--- a/src/include/access/gist.h
+++ b/src/include/access/gist.h
@@ -151,6 +151,10 @@ typedef struct GISTENTRY
 #define GistPageGetNSN(page) ( PageXLogRecPtrGet(GistPageGetOpaque(page)->nsn))
 #define GistPageSetNSN(page, val) ( PageXLogRecPtrSet(GistPageGetOpaque(page)->nsn, val))
 
+/* For deleted pages we store last xid which could see the page in scan */
+#define GistPageGetDeleteXid(page) ( ((PageHeader) (page))->pd_prune_xid )
+#define GistPageSetDeleteXid(page, val) ( ((PageHeader) (page))->pd_prune_xid = val)
+
 /*
  * Vector of GISTENTRY structs; user-defined methods union and picksplit
  * take it as one of their arguments
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index 463d2bfc7b9..02dc285a78a 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -414,12 +414,20 @@ extern bool gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
 extern SplitedPageLayout *gistSplit(Relation r, Page page, IndexTuple *itup,
 		  int len, GISTSTATE *giststate);
 
+/* gistxlog.c */
+extern XLogRecPtr gistXLogPageDelete(Buffer buffer,
+				   TransactionId xid, Buffer parentBuffer,
+				   OffsetNumber downlinkOffset);
+
+extern void gistXLogPageReuse(Relation rel, BlockNumber blkno,
+				  TransactionId latestRemovedXid);
+
 extern XLogRecPtr gistXLogUpdate(Buffer buffer,
 			   OffsetNumber *todelete, int ntodelete,
 			   IndexTuple *itup, int ntup,
 			   Buffer leftchild);
 
-XLogRecPtr gistXLogDelete(Buffer buffer, OffsetNumber *todelete,
+extern XLogRecPtr gistXLogDelete(Buffer buffer, OffsetNumber *todelete,
 			   int ntodelete, RelFileNode hnode);
 
 extern XLogRecPtr gistXLogSplit(bool page_is_leaf,
@@ -451,6 +459,7 @@ extern bool gistfitpage(IndexTuple *itvec, int len);
 extern bool gistnospace(Page page, IndexTuple *itvec, int len, OffsetNumber todelete, Size freespace);
 extern void gistcheckpage(Relation rel, Buffer buf);
 extern Buffer gistNewBuffer(Relation r);
+extern bool gistPageRecyclable(Page page);
 extern void gistfillbuffer(Page page, IndexTuple *itup, int len,
 			   OffsetNumber off);
 extern IndexTuple *gistextractpage(Page page, int *len /* out */ );
diff --git a/src/include/access/gistxlog.h b/src/include/access/gistxlog.h
index 5117aabf1af..2f87b67a53a 100644
--- a/src/include/access/gistxlog.h
+++ b/src/include/access/gistxlog.h
@@ -19,11 +19,12 @@
 
 #define XLOG_GIST_PAGE_UPDATE		0x00
 #define XLOG_GIST_DELETE			0x10 /* delete leaf index tuples for a page */
- /* #define XLOG_GIST_NEW_ROOT			 0x20 */	/* not used anymore */
+#define XLOG_GIST_PAGE_REUSE		0x20 /* old page is about to be reused from
+										  * FSM */
 #define XLOG_GIST_PAGE_SPLIT		0x30
  /* #define XLOG_GIST_INSERT_COMPLETE	 0x40 */	/* not used anymore */
 #define XLOG_GIST_CREATE_INDEX		0x50
- /* #define XLOG_GIST_PAGE_DELETE		 0x60 */	/* not used anymore */
+#define XLOG_GIST_PAGE_DELETE		0x60
 
 /*
  * Backup Blk 0: updated page.
@@ -76,6 +77,31 @@ typedef struct gistxlogPageSplit
 	 */
 } gistxlogPageSplit;
 
+/*
+ * Backup Blk 0: page that was deleted.
+ * Backup Blk 1: parent page, containing the downlink to the deleted page.
+ */
+typedef struct gistxlogPageDelete
+{
+	TransactionId deleteXid;	/* last Xid which could see page in scan */
+	OffsetNumber downlinkOffset; /* Offset of downlink referencing this page */
+} gistxlogPageDelete;
+
+#define SizeOfGistxlogPageDelete	(offsetof(gistxlogPageDelete, downlinkOffset) + sizeof(OffsetNumber))
+
+
+/*
+ * This is what we need to know about page reuse, for hot standby.
+ */
+typedef struct gistxlogPageReuse
+{
+	RelFileNode node;
+	BlockNumber block;
+	TransactionId latestRemovedXid;
+} gistxlogPageReuse;
+
+#define SizeOfGistxlogPageReuse	(offsetof(gistxlogPageReuse, latestRemovedXid) + sizeof(TransactionId))
+
 extern void gist_redo(XLogReaderState *record);
 extern void gist_desc(StringInfo buf, XLogReaderState *record);
 extern const char *gist_identify(uint8 info);