/*
* redo delete on gist index page to remove tuples marked as DEAD during index
* tuple insertion
*/
static void
gistRedoDeleteRecord(XLogReaderState *record)
{
XLogRecPtr lsn = record->EndRecPtr;
gistxlogDelete *xldata = (gistxlogDelete *) XLogRecGetData(record);
Buffer buffer;
Page page;
/*
* If we have any conflict processing to do, it must happen before we
* update the page.
*
* GiST delete records can conflict with standby queries. You might think
* that vacuum records would conflict as well, but we've handled that
* already. XLOG_HEAP2_CLEANUP_INFO records provide the highest xid
* cleaned by the vacuum of the heap and so we can resolve any conflicts
* just once when that arrives. After that we know that no conflicts
* exist from individual gist vacuum records on that index.
*/
if (InHotStandby)
{
TransactionId latestRemovedXid = gistRedoDeleteRecordGetLatestRemovedXid(record);
RelFileNode rnode;
XLogRecGetBlockTag(record, 0, &rnode, NULL, NULL);
ResolveRecoveryConflictWithSnapshot(latestRemovedXid, rnode);
}
if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
{
page = (Page) BufferGetPage(buffer);
if (XLogRecGetDataLen(record) > SizeOfGistxlogDelete)
{
OffsetNumber *todelete;
todelete = (OffsetNumber *) ((char *) xldata + SizeOfGistxlogDelete);
PageIndexMultiDelete(page, todelete, xldata->ntodelete);
}
GistClearPageHasGarbage(page);
GistMarkTuplesDeleted(page);
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
}
if (BufferIsValid(buffer))
UnlockReleaseBuffer(buffer);
}
/*
* Mask a Gist page before running consistency checks on it.
*/
void
gist_mask(char *pagedata, BlockNumber blkno)
{
Page page = (Page) pagedata;
mask_page_lsn_and_checksum(page);
mask_page_hint_bits(page);
mask_unused_space(page);
/*
* NSN is nothing but a special purpose LSN. Hence, mask it for the same
* reason as mask_page_lsn_and_checksum.
*/
GistPageSetNSN(page, (uint64) MASK_MARKER);
/*
* We update F_FOLLOW_RIGHT flag on the left child after writing WAL
* record. Hence, mask this flag. See gistplacetopage() for details.
*/
GistMarkFollowRight(page);
if (GistPageIsLeaf(page))
{
/*
* In gist leaf pages, it is possible to modify the LP_FLAGS without
* emitting any WAL record. Hence, mask the line pointer flags. See
* gistkillitems() for details.
*/
mask_lp_flags(page);
}
/*
* During gist redo, we never mark a page as garbage. Hence, mask it to
* ignore any differences.
*/
GistClearPageHasGarbage(page);
}
