index 12be87efed4fef5938afd05bb20f39f0e25c2006..560f1c81a2c0a58e1e5ac6e4e9534fbef102eb38 100644 (file)
* full-page writes. This exposes us to torn page hazards, but since
* we're not inspecting the existing page contents in any way, we
* don't care.
- *
- * However, all operations that clear the visibility map bit *do* bump
- * the LSN, and those operations will only be replayed if the XLOG LSN
- * follows the page LSN. Thus, if the page LSN has advanced past our
- * XLOG record's LSN, we mustn't mark the page all-visible, because
- * the subsequent update won't be replayed to clear the flag.
*/
page = BufferGetPage(buffer);
reln = CreateFakeRelcacheEntry(rlocator);
visibilitymap_pin(reln, blkno, &vmbuffer);
- /*
- * Don't set the bit if replay has already passed this point.
- *
- * It might be safe to do this unconditionally; if replay has passed
- * this point, we'll replay at least as far this time as we did
- * before, and if this bit needs to be cleared, the record responsible
- * for doing so should be again replayed, and clear it. For right
- * now, out of an abundance of conservatism, we use the same test here
- * we did for the heap page. If this results in a dropped bit, no
- * real harm is done; and the next VACUUM will fix it.
- */
- if (lsn > PageGetLSN(vmpage))
- visibilitymap_set(reln, blkno, InvalidBuffer, lsn, vmbuffer,
- xlrec->cutoff_xid, xlrec->flags);
+ visibilitymap_set(reln, blkno, InvalidBuffer, lsn, vmbuffer,
+ xlrec->cutoff_xid, xlrec->flags);
ReleaseBuffer(vmbuffer);
FreeFakeRelcacheEntry(reln);