Further minor improvement in generic_xlog.c: always say REGBUF_STANDARD.

tglsfdc · tglsfdc · commit 660d5fb856c6 · 2016-04-10T00:24:28.000-04:00
Since we're requiring pages handled by generic_xlog.c to be standard
format, specify REGBUF_STANDARD when doing a full-page image, so that
xloginsert.c can compress out the "hole" between pd_lower and pd_upper.
Given the current API in which this path will be taken only for a newly
initialized page, the hole is likely to be particularly large in such
cases, so that this oversight could easily be performance-significant.
I don't notice any particular change in the runtime of contrib/bloom's
regression test, though.
diff --git a/src/backend/access/transam/generic_xlog.c b/src/backend/access/transam/generic_xlog.c
@@ -349,7 +349,8 @@ GenericXLogFinish(GenericXLogState *state)
 			{
 				/* A full page image does not require anything special */
 				memcpy(page, pageData->image, BLCKSZ);
-				XLogRegisterBuffer(i, pageData->buffer, REGBUF_FORCE_IMAGE);
+				XLogRegisterBuffer(i, pageData->buffer,
+								   REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
 			}
 			else
 			{

Original file line number	Diff line number	Diff line change
`@@ -349,7 +349,8 @@ GenericXLogFinish(GenericXLogState *state)`
`349`	`349`	`{`
`350`	`350`	`/* A full page image does not require anything special */`
`351`	`351`	`memcpy(page, pageData->image, BLCKSZ);`
`352`		`- XLogRegisterBuffer(i, pageData->buffer, REGBUF_FORCE_IMAGE);`
	`352`	`+ XLogRegisterBuffer(i, pageData->buffer,`
	`353`	`+ REGBUF_FORCE_IMAGE \| REGBUF_STANDARD);`
`353`	`354`	`}`
`354`	`355`	`else`
`355`	`356`	`{`