Force zero_damaged_pages to be effectively ON during recovery from WAL,

since there is no need to worry about damaged pages when we are going to
overwrite them anyway from the WAL.  Per recent discussion.

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index f155619fa91edaf6d7837824d050df3d7dc41f18..85d62914e86ded3dda9698a1840e004c0e040d28 100644 (file)
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -227,7 +227,13 @@ ReadBufferInternal(Relation reln, BlockNumber blockNum,
                if (status == SM_SUCCESS &&
                        !PageHeaderIsValid((PageHeader) MAKE_PTR(bufHdr->data)))
                {
-                       if (zero_damaged_pages)
+                       /*
+                        * During WAL recovery, the first access to any data page should
+                        * overwrite the whole page from the WAL; so a clobbered page
+                        * header is not reason to fail.  Hence, when InRecovery we may
+                        * always act as though zero_damaged_pages is ON.
+                        */
+                       if (zero_damaged_pages || InRecovery)
                        {
                                ereport(WARNING,
                                                (errcode(ERRCODE_DATA_CORRUPTED),