/*
* Build an empty SPGiST index in the initialization fork
*/
Datum
spgbuildempty(PG_FUNCTION_ARGS)
{
Relation index = (Relation) PG_GETARG_POINTER(0);
Page page;
/* Construct metapage. */
page = (Page) palloc(BLCKSZ);
SpGistInitMetapage(page);
/* Write the page. If archiving/streaming, XLOG it. */
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_METAPAGE_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_METAPAGE_BLKNO, page);
/* Likewise for the root page. */
SpGistInitPage(page, SPGIST_LEAF);
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_HEAD_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_HEAD_BLKNO, page);
/*
* An immediate sync is required even if we xlog'd the pages, because the
* writes did not go through shared buffers and therefore a concurrent
* checkpoint may have moved the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
PG_RETURN_VOID();
}
/*
* btbuildempty() -- build an empty btree index in the initialization fork
*/
void
btbuildempty(Relation index)
{
Page metapage;
/* Construct metapage. */
metapage = (Page) palloc(BLCKSZ);
_bt_initmetapage(metapage, P_NONE, 0);
/*
* Write the page and log it. It might seem that an immediate sync would
* be sufficient to guarantee that the file exists on disk, but recovery
* itself might remove it while replaying, for example, an
* XLOG_DBASE_CREATE or XLOG_TBLSPC_CREATE record. Therefore, we need
* this even when wal_level=minimal.
*/
PageSetChecksumInplace(metapage, BTREE_METAPAGE);
smgrwrite(index->rd_smgr, INIT_FORKNUM, BTREE_METAPAGE,
(char *) metapage, true);
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
BTREE_METAPAGE, metapage, true);
/*
* An immediate sync is required even if we xlog'd the page, because the
* write did not go through shared_buffers and therefore a concurrent
* checkpoint may have moved the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
}
/*
* btbuildempty() -- build an empty btree index in the initialization fork
*/
Datum
btbuildempty(PG_FUNCTION_ARGS)
{
Relation index = (Relation) PG_GETARG_POINTER(0);
Page metapage;
/* Construct metapage. */
metapage = (Page) palloc(BLCKSZ);
_bt_initmetapage(metapage, P_NONE, 0);
/* Write the page. If archiving/streaming, XLOG it. */
smgrwrite(index->rd_smgr, INIT_FORKNUM, BTREE_METAPAGE,
(char *) metapage, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
BTREE_METAPAGE, metapage);
/*
* An immediate sync is require even if we xlog'd the page, because the
* write did not go through shared_buffers and therefore a concurrent
* checkpoint may have move the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
PG_RETURN_VOID();
}
/*
* SetMatViewToPopulated
* Indicate that the materialized view has been populated by its query.
*
* NOTE: The heap starts out in a state that doesn't look scannable, and can
* only transition from there to scannable at the time a new heap is created.
*
* NOTE: caller must be holding an appropriate lock on the relation.
*/
void
SetMatViewToPopulated(Relation relation)
{
Page page;
Assert(relation->rd_rel->relkind == RELKIND_MATVIEW);
Assert(relation->rd_ispopulated == false);
page = (Page) palloc(BLCKSZ);
PageInit(page, BLCKSZ, 0);
if (RelationNeedsWAL(relation))
log_newpage(&(relation->rd_node), MAIN_FORKNUM, 0, page);
RelationOpenSmgr(relation);
PageSetChecksumInplace(page, 0);
smgrextend(relation->rd_smgr, MAIN_FORKNUM, 0, (char *) page, true);
pfree(page);
smgrimmedsync(relation->rd_smgr, MAIN_FORKNUM);
RelationCacheInvalidateEntry(relation->rd_id);
}
/*
* Build an empty SPGiST index in the initialization fork
*/
void
spgbuildempty(Relation index)
{
Page page;
/* Construct metapage. */
page = (Page) palloc(BLCKSZ);
SpGistInitMetapage(page);
/* Write the page. If archiving/streaming, XLOG it. */
PageSetChecksumInplace(page, SPGIST_METAPAGE_BLKNO);
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_METAPAGE_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_METAPAGE_BLKNO, page, false);
/* Likewise for the root page. */
SpGistInitPage(page, SPGIST_LEAF);
PageSetChecksumInplace(page, SPGIST_ROOT_BLKNO);
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_ROOT_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_ROOT_BLKNO, page, true);
/* Likewise for the null-tuples root page. */
SpGistInitPage(page, SPGIST_LEAF | SPGIST_NULLS);
PageSetChecksumInplace(page, SPGIST_NULL_BLKNO);
smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_NULL_BLKNO,
(char *) page, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
SPGIST_NULL_BLKNO, page, true);
/*
* An immediate sync is required even if we xlog'd the pages, because the
* writes did not go through shared buffers and therefore a concurrent
* checkpoint may have moved the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
}
/*
* emit a completed btree page, and release the working storage.
*/
static void
_bt_blwritepage(BTWriteState *wstate, Page page, BlockNumber blkno)
{
/* Ensure rd_smgr is open (could have been closed by relcache flush!) */
RelationOpenSmgr(wstate->index);
/* XLOG stuff */
if (wstate->btws_use_wal)
{
/* We use the heap NEWPAGE record type for this */
log_newpage(&wstate->index->rd_node, MAIN_FORKNUM, blkno, page);
}
else
{
/* Leave the page LSN zero if not WAL-logged, but set TLI anyway */
PageSetTLI(page, ThisTimeLineID);
}
/*
* If we have to write pages nonsequentially, fill in the space with
* zeroes until we come back and overwrite. This is not logically
* necessary on standard Unix filesystems (unwritten space will read as
* zeroes anyway), but it should help to avoid fragmentation. The dummy
* pages aren't WAL-logged though.
*/
while (blkno > wstate->btws_pages_written)
{
if (!wstate->btws_zeropage)
wstate->btws_zeropage = (Page) palloc0(BLCKSZ);
smgrextend(wstate->index->rd_smgr, MAIN_FORKNUM,
wstate->btws_pages_written++,
(char *) wstate->btws_zeropage,
true);
}
/*
* Now write the page. We say isTemp = true even if it's not a temp
* index, because there's no need for smgr to schedule an fsync for this
* write; we'll do it ourselves before ending the build.
*/
if (blkno == wstate->btws_pages_written)
{
/* extending the file... */
smgrextend(wstate->index->rd_smgr, MAIN_FORKNUM, blkno,
(char *) page, true);
wstate->btws_pages_written++;
}
else
{
/* overwriting a block we zero-filled before */
smgrwrite(wstate->index->rd_smgr, MAIN_FORKNUM, blkno,
(char *) page, true);
}
pfree(page);
}
/*
* End a rewrite.
*
* state and any other resources are freed.
*/
void
end_heap_rewrite(RewriteState state)
{
HASH_SEQ_STATUS seq_status;
UnresolvedTup unresolved;
/*
* Write any remaining tuples in the UnresolvedTups table. If we have any
* left, they should in fact be dead, but let's err on the safe side.
*/
hash_seq_init(&seq_status, state->rs_unresolved_tups);
while ((unresolved = hash_seq_search(&seq_status)) != NULL)
{
ItemPointerSetInvalid(&unresolved->tuple->t_data->t_ctid);
raw_heap_insert(state, unresolved->tuple);
}
/* Write the last page, if any */
if (state->rs_buffer_valid)
{
if (state->rs_use_wal)
log_newpage(&state->rs_new_rel->rd_node,
MAIN_FORKNUM,
state->rs_blockno,
state->rs_buffer,
true);
RelationOpenSmgr(state->rs_new_rel);
PageSetChecksumInplace(state->rs_buffer, state->rs_blockno);
smgrextend(state->rs_new_rel->rd_smgr, MAIN_FORKNUM, state->rs_blockno,
(char *) state->rs_buffer, true);
}
/*
* If the rel is WAL-logged, must fsync before commit. We use heap_sync
* to ensure that the toast table gets fsync'd too.
*
* It's obvious that we must do this when not WAL-logging. It's less
* obvious that we have to do it even if we did WAL-log the pages. The
* reason is the same as in tablecmds.c's copy_relation_data(): we're
* writing data that's not in shared buffers, and so a CHECKPOINT
* occurring during the rewriteheap operation won't have fsync'd data we
* wrote before the checkpoint.
*/
if (RelationNeedsWAL(state->rs_new_rel))
heap_sync(state->rs_new_rel);
/* Deleting the context frees everything */
MemoryContextDelete(state->rs_cxt);
}
/*
* ginbuildempty() -- build an empty gin index in the initialization fork
*/
Datum
ginbuildempty(PG_FUNCTION_ARGS)
{
Relation index = (Relation) PG_GETARG_POINTER(0);
Buffer RootBuffer,
MetaBuffer;
/* An empty GIN index has two pages. */
MetaBuffer =
ReadBufferExtended(index, INIT_FORKNUM, P_NEW, RBM_NORMAL, NULL);
LockBuffer(MetaBuffer, BUFFER_LOCK_EXCLUSIVE);
RootBuffer =
ReadBufferExtended(index, INIT_FORKNUM, P_NEW, RBM_NORMAL, NULL);
LockBuffer(RootBuffer, BUFFER_LOCK_EXCLUSIVE);
/* Initialize both pages, mark them dirty, unlock and release buffer. */
START_CRIT_SECTION();
GinInitMetabuffer(MetaBuffer);
MarkBufferDirty(MetaBuffer);
GinInitBuffer(RootBuffer, GIN_LEAF);
MarkBufferDirty(RootBuffer);
/* XLOG the new pages */
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
BufferGetBlockNumber(MetaBuffer),
BufferGetPage(MetaBuffer));
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
BufferGetBlockNumber(RootBuffer),
BufferGetPage(RootBuffer));
END_CRIT_SECTION();
/* Unlock and release the buffers. */
UnlockReleaseBuffer(MetaBuffer);
UnlockReleaseBuffer(RootBuffer);
PG_RETURN_VOID();
}
/*
* Write a WAL record containing a full image of a page.
*
* Caller should initialize the buffer and mark it dirty before calling this
* function. This function will set the page LSN.
*
* If the page follows the standard page layout, with a PageHeader and unused
* space between pd_lower and pd_upper, set 'page_std' to TRUE. That allows
* the unused space to be left out from the WAL record, making it smaller.
*/
XLogRecPtr
log_newpage_buffer(Buffer buffer, bool page_std)
{
Page page = BufferGetPage(buffer);
RelFileNode rnode;
ForkNumber forkNum;
BlockNumber blkno;
/* Shared buffers should be modified in a critical section. */
Assert(CritSectionCount > 0);
BufferGetTag(buffer, &rnode, &forkNum, &blkno);
return log_newpage(&rnode, forkNum, blkno, page, page_std);
}
/*
* _hash_alloc_buckets -- allocate a new splitpoint's worth of bucket pages
*
* This does not need to initialize the new bucket pages; we'll do that as
* each one is used by _hash_expandtable(). But we have to extend the logical
* EOF to the end of the splitpoint; this keeps smgr's idea of the EOF in
* sync with ours, so that we don't get complaints from smgr.
*
* We do this by writing a page of zeroes at the end of the splitpoint range.
* We expect that the filesystem will ensure that the intervening pages read
* as zeroes too. On many filesystems this "hole" will not be allocated
* immediately, which means that the index file may end up more fragmented
* than if we forced it all to be allocated now; but since we don't scan
* hash indexes sequentially anyway, that probably doesn't matter.
*
* XXX It's annoying that this code is executed with the metapage lock held.
* We need to interlock against _hash_addovflpage() adding a new overflow page
* concurrently, but it'd likely be better to use LockRelationForExtension
* for the purpose. OTOH, adding a splitpoint is a very infrequent operation,
* so it may not be worth worrying about.
*
* Returns TRUE if successful, or FALSE if allocation failed due to
* BlockNumber overflow.
*/
static bool
_hash_alloc_buckets(Relation rel, BlockNumber firstblock, uint32 nblocks)
{
BlockNumber lastblock;
char zerobuf[BLCKSZ];
Page page;
HashPageOpaque ovflopaque;
lastblock = firstblock + nblocks - 1;
/*
* Check for overflow in block number calculation; if so, we cannot extend
* the index anymore.
*/
if (lastblock < firstblock || lastblock == InvalidBlockNumber)
return false;
page = (Page) zerobuf;
/*
* Initialize the page. Just zeroing the page won't work; see
* _hash_freeovflpage for similar usage. We take care to make the special
* space valid for the benefit of tools such as pageinspect.
*/
_hash_pageinit(page, BLCKSZ);
ovflopaque = (HashPageOpaque) PageGetSpecialPointer(page);
ovflopaque->hasho_prevblkno = InvalidBlockNumber;
ovflopaque->hasho_nextblkno = InvalidBlockNumber;
ovflopaque->hasho_bucket = -1;
ovflopaque->hasho_flag = LH_UNUSED_PAGE;
ovflopaque->hasho_page_id = HASHO_PAGE_ID;
if (RelationNeedsWAL(rel))
log_newpage(&rel->rd_node,
MAIN_FORKNUM,
lastblock,
zerobuf,
true);
RelationOpenSmgr(rel);
smgrextend(rel->rd_smgr, MAIN_FORKNUM, lastblock, zerobuf, false);
return true;
}
/*
* btbuildempty() -- build an empty btree index in the initialization fork
*/
void
btbuildempty(Relation index)
{
Page metapage;
/* Construct metapage. */
metapage = (Page) palloc(BLCKSZ);
_bt_initmetapage(metapage, P_NONE, 0);
/* Write the page. If archiving/streaming, XLOG it. */
PageSetChecksumInplace(metapage, BTREE_METAPAGE);
smgrwrite(index->rd_smgr, INIT_FORKNUM, BTREE_METAPAGE,
(char *) metapage, true);
if (XLogIsNeeded())
log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM,
BTREE_METAPAGE, metapage, false);
/*
* An immediate sync is required even if we xlog'd the page, because the
* write did not go through shared_buffers and therefore a concurrent
* checkpoint may have moved the redo pointer past our xlog record.
*/
smgrimmedsync(index->rd_smgr, INIT_FORKNUM);
}
/*
* Insert a tuple to the new relation. This has to track heap_insert
* and its subsidiary functions!
*
* t_self of the tuple is set to the new TID of the tuple. If t_ctid of the
* tuple is invalid on entry, it's replaced with the new TID as well (in
* the inserted data only, not in the caller's copy).
*/
static void
raw_heap_insert(RewriteState state, HeapTuple tup)
{
Page page = state->rs_buffer;
Size pageFreeSpace,
saveFreeSpace;
Size len;
OffsetNumber newoff;
HeapTuple heaptup;
/*
* If the new tuple is too big for storage or contains already toasted
* out-of-line attributes from some other relation, invoke the toaster.
*
* Note: below this point, heaptup is the data we actually intend to store
* into the relation; tup is the caller's original untoasted data.
*/
if (state->rs_new_rel->rd_rel->relkind == RELKIND_TOASTVALUE)
{
/* toast table entries should never be recursively toasted */
Assert(!HeapTupleHasExternal(tup));
heaptup = tup;
}
else if (HeapTupleHasExternal(tup) || tup->t_len > TOAST_TUPLE_THRESHOLD)
heaptup = toast_insert_or_update(state->rs_new_rel, tup, NULL,
HEAP_INSERT_SKIP_FSM |
(state->rs_use_wal ?
0 : HEAP_INSERT_SKIP_WAL));
else
heaptup = tup;
len = MAXALIGN(heaptup->t_len); /* be conservative */
/*
* If we're gonna fail for oversize tuple, do it right away
*/
if (len > MaxHeapTupleSize)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("row is too big: size %zu, maximum size %zu",
len, MaxHeapTupleSize)));
/* Compute desired extra freespace due to fillfactor option */
saveFreeSpace = RelationGetTargetPageFreeSpace(state->rs_new_rel,
HEAP_DEFAULT_FILLFACTOR);
/* Now we can check to see if there's enough free space already. */
if (state->rs_buffer_valid)
{
pageFreeSpace = PageGetHeapFreeSpace(page);
if (len + saveFreeSpace > pageFreeSpace)
{
/* Doesn't fit, so write out the existing page */
/* XLOG stuff */
if (state->rs_use_wal)
log_newpage(&state->rs_new_rel->rd_node,
MAIN_FORKNUM,
state->rs_blockno,
page,
true);
/*
* Now write the page. We say isTemp = true even if it's not a
* temp table, because there's no need for smgr to schedule an
* fsync for this write; we'll do it ourselves in
* end_heap_rewrite.
*/
RelationOpenSmgr(state->rs_new_rel);
PageSetChecksumInplace(page, state->rs_blockno);
smgrextend(state->rs_new_rel->rd_smgr, MAIN_FORKNUM,
state->rs_blockno, (char *) page, true);
state->rs_blockno++;
state->rs_buffer_valid = false;
}
}
if (!state->rs_buffer_valid)
{
/* Initialize a new empty page */
PageInit(page, BLCKSZ, 0);
state->rs_buffer_valid = true;
}
/* And now we can insert the tuple into the page */
newoff = PageAddItem(page, (Item) heaptup->t_data, heaptup->t_len,
InvalidOffsetNumber, false, true);
if (newoff == InvalidOffsetNumber)
elog(ERROR, "failed to add tuple");
/* Update caller's t_self to the actual position where it was stored */
ItemPointerSet(&(tup->t_self), state->rs_blockno, newoff);
/*
* Insert the correct position into CTID of the stored tuple, too, if the
* caller didn't supply a valid CTID.
*/
if (!ItemPointerIsValid(&tup->t_data->t_ctid))
{
ItemId newitemid;
HeapTupleHeader onpage_tup;
newitemid = PageGetItemId(page, newoff);
onpage_tup = (HeapTupleHeader) PageGetItem(page, newitemid);
onpage_tup->t_ctid = tup->t_self;
}
/* If heaptup is a private copy, release it. */
if (heaptup != tup)
heap_freetuple(heaptup);
}
/*
* _hash_init() -- Initialize the metadata page of a hash index,
* the initial buckets, and the initial bitmap page.
*
* The initial number of buckets is dependent on num_tuples, an estimate
* of the number of tuples to be loaded into the index initially. The
* chosen number of buckets is returned.
*
* We are fairly cavalier about locking here, since we know that no one else
* could be accessing this index. In particular the rule about not holding
* multiple buffer locks is ignored.
*/
uint32
_hash_init(Relation rel, double num_tuples, ForkNumber forkNum)
{
Buffer metabuf;
Buffer buf;
Buffer bitmapbuf;
Page pg;
HashMetaPage metap;
RegProcedure procid;
int32 data_width;
int32 item_width;
int32 ffactor;
uint32 num_buckets;
uint32 i;
bool use_wal;
/* safety check */
if (RelationGetNumberOfBlocksInFork(rel, forkNum) != 0)
elog(ERROR, "cannot initialize non-empty hash index \"%s\"",
RelationGetRelationName(rel));
/*
* WAL log creation of pages if the relation is persistent, or this is the
* init fork. Init forks for unlogged relations always need to be WAL
* logged.
*/
use_wal = RelationNeedsWAL(rel) || forkNum == INIT_FORKNUM;
/*
* Determine the target fill factor (in tuples per bucket) for this index.
* The idea is to make the fill factor correspond to pages about as full
* as the user-settable fillfactor parameter says. We can compute it
* exactly since the index datatype (i.e. uint32 hash key) is fixed-width.
*/
data_width = sizeof(uint32);
item_width = MAXALIGN(sizeof(IndexTupleData)) + MAXALIGN(data_width) +
sizeof(ItemIdData); /* include the line pointer */
ffactor = RelationGetTargetPageUsage(rel, HASH_DEFAULT_FILLFACTOR) / item_width;
/* keep to a sane range */
if (ffactor < 10)
ffactor = 10;
procid = index_getprocid(rel, 1, HASHSTANDARD_PROC);
/*
* We initialize the metapage, the first N bucket pages, and the first
* bitmap page in sequence, using _hash_getnewbuf to cause smgrextend()
* calls to occur. This ensures that the smgr level has the right idea of
* the physical index length.
*
* Critical section not required, because on error the creation of the
* whole relation will be rolled back.
*/
metabuf = _hash_getnewbuf(rel, HASH_METAPAGE, forkNum);
_hash_init_metabuffer(metabuf, num_tuples, procid, ffactor, false);
MarkBufferDirty(metabuf);
pg = BufferGetPage(metabuf);
metap = HashPageGetMeta(pg);
/* XLOG stuff */
if (use_wal)
{
xl_hash_init_meta_page xlrec;
XLogRecPtr recptr;
xlrec.num_tuples = num_tuples;
xlrec.procid = metap->hashm_procid;
xlrec.ffactor = metap->hashm_ffactor;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, SizeOfHashInitMetaPage);
XLogRegisterBuffer(0, metabuf, REGBUF_WILL_INIT);
recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INIT_META_PAGE);
PageSetLSN(BufferGetPage(metabuf), recptr);
}
num_buckets = metap->hashm_maxbucket + 1;
/*
* Release buffer lock on the metapage while we initialize buckets.
* Otherwise, we'll be in interrupt holdoff and the CHECK_FOR_INTERRUPTS
* won't accomplish anything. It's a bad idea to hold buffer locks for
* long intervals in any case, since that can block the bgwriter.
*/
LockBuffer(metabuf, BUFFER_LOCK_UNLOCK);
/*
* Initialize and WAL Log the first N buckets
*/
for (i = 0; i < num_buckets; i++)
{
BlockNumber blkno;
/* Allow interrupts, in case N is huge */
CHECK_FOR_INTERRUPTS();
blkno = BUCKET_TO_BLKNO(metap, i);
buf = _hash_getnewbuf(rel, blkno, forkNum);
_hash_initbuf(buf, metap->hashm_maxbucket, i, LH_BUCKET_PAGE, false);
MarkBufferDirty(buf);
if (use_wal)
log_newpage(&rel->rd_node,
forkNum,
blkno,
BufferGetPage(buf),
true);
_hash_relbuf(rel, buf);
}
/* Now reacquire buffer lock on metapage */
LockBuffer(metabuf, BUFFER_LOCK_EXCLUSIVE);
/*
* Initialize bitmap page
*/
bitmapbuf = _hash_getnewbuf(rel, num_buckets + 1, forkNum);
_hash_initbitmapbuffer(bitmapbuf, metap->hashm_bmsize, false);
MarkBufferDirty(bitmapbuf);
/* add the new bitmap page to the metapage's list of bitmaps */
/* metapage already has a write lock */
if (metap->hashm_nmaps >= HASH_MAX_BITMAPS)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("out of overflow pages in hash index \"%s\"",
RelationGetRelationName(rel))));
metap->hashm_mapp[metap->hashm_nmaps] = num_buckets + 1;
metap->hashm_nmaps++;
MarkBufferDirty(metabuf);
/* XLOG stuff */
if (use_wal)
{
xl_hash_init_bitmap_page xlrec;
XLogRecPtr recptr;
xlrec.bmsize = metap->hashm_bmsize;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, SizeOfHashInitBitmapPage);
XLogRegisterBuffer(0, bitmapbuf, REGBUF_WILL_INIT);
/*
* This is safe only because nobody else can be modifying the index at
* this stage; it's only visible to the transaction that is creating
* it.
*/
XLogRegisterBuffer(1, metabuf, REGBUF_STANDARD);
recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INIT_BITMAP_PAGE);
PageSetLSN(BufferGetPage(bitmapbuf), recptr);
PageSetLSN(BufferGetPage(metabuf), recptr);
}
/* all done */
_hash_relbuf(rel, bitmapbuf);
_hash_relbuf(rel, metabuf);
return num_buckets;
}
/**
* @brief Write block buffer contents. Number of block buffer to be
* written is specified by num argument.
*
* Flow:
* <ol>
* <li>If no more space is available in the data file, switch to a new one.</li>
* <li>Compute block number which can be written to the current file.</li>
* <li>Save the last block number in the load status file.</li>
* <li>Write to the current file.</li>
* <li>If there are other data, write them too.</li>
* </ol>
*
* @param loader [in] Direct Writer.
* @return File descriptor for the current data file.
*/
static void
flush_pages(DirectWriter *loader)
{
int i;
int num;
LoadStatus *ls = &loader->ls;
num = loader->curblk;
if (!PageIsEmpty(GetCurrentPage(loader)))
num += 1;
if (num <= 0)
return; /* no work */
/*
* Add WAL entry (only the first page) to ensure the current xid will
* be recorded in xlog. We must flush some xlog records with XLogFlush()
* before write any data blocks to follow the WAL protocol.
*
* If postgres process, such as loader and COPY, is killed by "kill -9",
* database will be rewound to the last checkpoint and recovery will
* be performed using WAL.
*
* After the recovery, if there are xid's which have not been recorded
* to WAL, such xid's will be reused.
*
* However, in the loader and COPY, data file is actually updated and
* xid must not be reused.
*
* WAL entry with such xid can be added using XLogInsert(). However,
* such entries are not really written to the disk immediately.
* WAL entries are flushed to the disk by XLogFlush(), typically
* when a transaction is commited. COPY prevents xid reuse by
* this method.
*/
#if PG_VERSION_NUM >= 90100
if (ls->ls.create_cnt == 0 && !RELATION_IS_LOCAL(loader->base.rel)
&& !(loader->base.rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED) )
{
XLogRecPtr recptr;
recptr = log_newpage(&ls->ls.rnode, MAIN_FORKNUM,
ls->ls.exist_cnt, loader->blocks);
XLogFlush(recptr);
}
#else
if (ls->ls.create_cnt == 0 && !RELATION_IS_LOCAL(loader->base.rel) )
{
XLogRecPtr recptr;
recptr = log_newpage(&ls->ls.rnode, MAIN_FORKNUM,
ls->ls.exist_cnt, loader->blocks);
XLogFlush(recptr);
}
#endif
/*
* Write blocks. We might need to write multiple files on boundary of
* relation segments.
*/
for (i = 0; i < num;)
{
char *buffer;
int total;
int written;
int flush_num;
BlockNumber relblks = LS_TOTAL_CNT(ls);
/* Switch to the next file if the current file has been filled up. */
if (relblks % RELSEG_SIZE == 0)
close_data_file(loader);
if (loader->datafd == -1)
loader->datafd = open_data_file(ls->ls.rnode,
RELATION_IS_LOCAL(loader->base.rel),
relblks);
/* Number of blocks to be added to the current file. */
flush_num = Min(num - i, RELSEG_SIZE - relblks % RELSEG_SIZE);
Assert(flush_num > 0);
/* Write the last block number to the load status file. */
UpdateLSF(loader, flush_num);
#if PG_VERSION_NUM >= 90300
/* If we need a checksum, add it */
if (DataChecksumsEnabled()){
int j = 0;
Page contained_page;
for ( j=0; j<flush_num; j++ ) {
contained_page = GetTargetPage(loader,j);
((PageHeader) contained_page)->pd_checksum =
pg_checksum_page((char *) contained_page, LS_TOTAL_CNT(ls) - 1 - j);
}
}
#endif
/*
* Flush flush_num data block to the current file.
* Then the current file size becomes RELSEG_SIZE self->blocks.
*/
buffer = loader->blocks + BLCKSZ * i;
total = BLCKSZ * flush_num;
written = 0;
while (total > 0)
{
int len = write(loader->datafd, buffer + written, total);
if (len == -1)
{
/* fatal error, do not want to write blocks anymore */
ereport(ERROR, (errcode_for_file_access(),
errmsg("could not write to data file: %m")));
}
written += len;
total -= len;
}
i += flush_num;
}
/*
* NOTICE: Be sure reset curblk to 0 and reinitialize recycled page
* if you will continue to use blocks.
*/
}
