postgrespro.git / summary / log / commit / refs

commit    ea7dace2aa21e79a7a8eb23c493bcd2057d9bd7e
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Sat Mar 07 18:31:17 2020 +0000

    Simplify/speed up assertion cross-check in ginCompressPostingList().
    
    I noticed while testing some other stuff that the CHECK_ENCODING_ROUNDTRIP
    logic in ginCompressPostingList could account for over 50% of the runtime
    of an INSERT with a GIN index.  While that's not relevant to production
    performance, it's still kind of annoying in a debug build.  Replacing
    the loop around short memcmp's with one long memcmp works just as well
    and is significantly faster, at least on my machine.


 src/backend/access/gin/ginpostinglist.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/backend/access/gin/ginpostinglist.c b/src/backend/access/gin/ginpostinglist.c
index 7dff2071d8..461ec93fde 100644
--- a/src/backend/access/gin/ginpostinglist.c
+++ b/src/backend/access/gin/ginpostinglist.c
@@ -266,11 +266,9 @@ ginCompressPostingList(const ItemPointer ipd, int nipd, int maxsize,
 	{
 		int			ndecoded;
 		ItemPointer tmp = ginPostingListDecode(result, &ndecoded);
-		int			i;
 
 		Assert(ndecoded == totalpacked);
-		for (i = 0; i < ndecoded; i++)
-			Assert(memcmp(&tmp[i], &ipd[i], sizeof(ItemPointerData)) == 0);
+		Assert(memcmp(tmp, ipd, ndecoded * sizeof(ItemPointerData)) == 0);
 		pfree(tmp);
 	}
 #endif


[parent: 7e39b968f118]