/*
* transientrel_startup --- executor startup
*/
static void
transientrel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
{
DR_transientrel *myState = (DR_transientrel *) self;
Relation transientrel;
transientrel = heap_open(myState->transientoid, NoLock);
/*
* Fill private fields of myState for use by later routines
*/
myState->transientrel = transientrel;
myState->output_cid = GetCurrentCommandId(true);
/*
* We can skip WAL-logging the insertions, unless PITR or streaming
* replication is in use. We can skip the FSM in any case.
*/
myState->hi_options = HEAP_INSERT_SKIP_FSM | HEAP_INSERT_FROZEN;
if (!XLogIsNeeded())
myState->hi_options |= HEAP_INSERT_SKIP_WAL;
myState->bistate = GetBulkInsertState();
/* Not using WAL requires smgr_targblock be initially invalid */
Assert(RelationGetTargetBlock(transientrel) == InvalidBlockNumber);
}
/*
* Initialize or update the local map of blocks to try, for when there is
* no FSM.
*
* When we initialize the map, the whole heap is potentially available to
* try. Testing revealed that trying every block can cause a small
* performance dip compared to when we use a FSM, so we try every other
* block instead.
*/
static void
fsm_local_set(Relation rel, BlockNumber cur_nblocks)
{
BlockNumber blkno,
cached_target_block;
/* The local map must not be set already. */
Assert(!FSM_LOCAL_MAP_EXISTS);
/*
* Starting at the current last block in the relation and working
* backwards, mark alternating blocks as available.
*/
blkno = cur_nblocks - 1;
while (true)
{
fsm_local_map.map[blkno] = FSM_LOCAL_AVAIL;
if (blkno >= 2)
blkno -= 2;
else
break;
}
/* Cache the number of blocks. */
fsm_local_map.nblocks = cur_nblocks;
/* Set the status of the cached target block to 'unavailable'. */
cached_target_block = RelationGetTargetBlock(rel);
if (cached_target_block != InvalidBlockNumber &&
cached_target_block < cur_nblocks)
fsm_local_map.map[cached_target_block] = FSM_LOCAL_NOT_AVAIL;
}
/*
* intorel_startup --- executor startup
*/
static void
intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
{
DR_intorel *myState = (DR_intorel *) self;
IntoClause *into = myState->into;
bool is_matview;
char relkind;
CreateStmt *create;
Oid intoRelationId;
Relation intoRelationDesc;
RangeTblEntry *rte;
Datum toast_options;
ListCell *lc;
int attnum;
static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
Assert(into != NULL); /* else somebody forgot to set it */
/* This code supports both CREATE TABLE AS and CREATE MATERIALIZED VIEW */
is_matview = (into->viewQuery != NULL);
relkind = is_matview ? RELKIND_MATVIEW : RELKIND_RELATION;
/*
* Create the target relation by faking up a CREATE TABLE parsetree and
* passing it to DefineRelation.
*/
create = makeNode(CreateStmt);
create->relation = into->rel;
create->tableElts = NIL; /* will fill below */
create->inhRelations = NIL;
create->ofTypename = NULL;
create->constraints = NIL;
create->options = into->options;
create->oncommit = into->onCommit;
create->tablespacename = into->tableSpaceName;
create->if_not_exists = false;
/*
* Build column definitions using "pre-cooked" type and collation info. If
* a column name list was specified in CREATE TABLE AS, override the
* column names derived from the query. (Too few column names are OK, too
* many are not.)
*/
lc = list_head(into->colNames);
for (attnum = 0; attnum < typeinfo->natts; attnum++)
{
Form_pg_attribute attribute = typeinfo->attrs[attnum];
ColumnDef *col = makeNode(ColumnDef);
TypeName *coltype = makeNode(TypeName);
if (lc)
{
col->colname = strVal(lfirst(lc));
lc = lnext(lc);
}
else
col->colname = NameStr(attribute->attname);
col->typeName = coltype;
col->inhcount = 0;
col->is_local = true;
col->is_not_null = false;
col->is_from_type = false;
col->storage = 0;
col->raw_default = NULL;
col->cooked_default = NULL;
col->collClause = NULL;
col->collOid = attribute->attcollation;
col->constraints = NIL;
col->fdwoptions = NIL;
coltype->names = NIL;
coltype->typeOid = attribute->atttypid;
coltype->setof = false;
coltype->pct_type = false;
coltype->typmods = NIL;
coltype->typemod = attribute->atttypmod;
coltype->arrayBounds = NIL;
coltype->location = -1;
/*
* It's possible that the column is of a collatable type but the
* collation could not be resolved, so double-check. (We must check
* this here because DefineRelation would adopt the type's default
* collation rather than complaining.)
*/
if (!OidIsValid(col->collOid) &&
type_is_collatable(coltype->typeOid))
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("no collation was derived for column \"%s\" with collatable type %s",
col->colname, format_type_be(coltype->typeOid)),
errhint("Use the COLLATE clause to set the collation explicitly.")));
create->tableElts = lappend(create->tableElts, col);
}
if (lc != NULL)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("too many column names were specified")));
/*
* Actually create the target table
*/
intoRelationId = DefineRelation(create, relkind, InvalidOid);
/*
* If necessary, create a TOAST table for the target table. Note that
* AlterTableCreateToastTable ends with CommandCounterIncrement(), so that
* the TOAST table will be visible for insertion.
*/
CommandCounterIncrement();
/* parse and validate reloptions for the toast table */
toast_options = transformRelOptions((Datum) 0,
create->options,
"toast",
validnsps,
true, false);
(void) heap_reloptions(RELKIND_TOASTVALUE, toast_options, true);
AlterTableCreateToastTable(intoRelationId, toast_options);
/* Create the "view" part of a materialized view. */
if (is_matview)
{
/* StoreViewQuery scribbles on tree, so make a copy */
Query *query = (Query *) copyObject(into->viewQuery);
StoreViewQuery(intoRelationId, query, false);
CommandCounterIncrement();
}
/*
* Finally we can open the target table
*/
intoRelationDesc = heap_open(intoRelationId, AccessExclusiveLock);
/*
* Check INSERT permission on the constructed table.
*
* XXX: It would arguably make sense to skip this check if into->skipData
* is true.
*/
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = intoRelationId;
rte->relkind = relkind;
rte->requiredPerms = ACL_INSERT;
for (attnum = 1; attnum <= intoRelationDesc->rd_att->natts; attnum++)
rte->modifiedCols = bms_add_member(rte->modifiedCols,
attnum - FirstLowInvalidHeapAttributeNumber);
ExecCheckRTPerms(list_make1(rte), true);
/*
* Tentatively mark the target as populated, if it's a matview and we're
* going to fill it; otherwise, no change needed.
*/
if (is_matview && !into->skipData)
SetMatViewPopulatedState(intoRelationDesc, true);
/*
* Fill private fields of myState for use by later routines
*/
myState->rel = intoRelationDesc;
myState->output_cid = GetCurrentCommandId(true);
/*
* We can skip WAL-logging the insertions, unless PITR or streaming
* replication is in use. We can skip the FSM in any case.
*/
myState->hi_options = HEAP_INSERT_SKIP_FSM |
(XLogIsNeeded() ? 0 : HEAP_INSERT_SKIP_WAL);
myState->bistate = GetBulkInsertState();
/* Not using WAL requires smgr_targblock be initially invalid */
Assert(RelationGetTargetBlock(intoRelationDesc) == InvalidBlockNumber);
}
/*
* RelationGetBufferForTuple
*
* Returns pinned and exclusive-locked buffer of a page in given relation
* with free space >= given len.
*
* If otherBuffer is not InvalidBuffer, then it references a previously
* pinned buffer of another page in the same relation; on return, this
* buffer will also be exclusive-locked. (This case is used by heap_update;
* the otherBuffer contains the tuple being updated.)
*
* The reason for passing otherBuffer is that if two backends are doing
* concurrent heap_update operations, a deadlock could occur if they try
* to lock the same two buffers in opposite orders. To ensure that this
* can't happen, we impose the rule that buffers of a relation must be
* locked in increasing page number order. This is most conveniently done
* by having RelationGetBufferForTuple lock them both, with suitable care
* for ordering.
*
* NOTE: it is unlikely, but not quite impossible, for otherBuffer to be the
* same buffer we select for insertion of the new tuple (this could only
* happen if space is freed in that page after heap_update finds there's not
* enough there). In that case, the page will be pinned and locked only once.
*
* For the vmbuffer and vmbuffer_other arguments, we avoid deadlock by
* locking them only after locking the corresponding heap page, and taking
* no further lwlocks while they are locked.
*
* We normally use FSM to help us find free space. However,
* if HEAP_INSERT_SKIP_FSM is specified, we just append a new empty page to
* the end of the relation if the tuple won't fit on the current target page.
* This can save some cycles when we know the relation is new and doesn't
* contain useful amounts of free space.
*
* HEAP_INSERT_SKIP_FSM is also useful for non-WAL-logged additions to a
* relation, if the caller holds exclusive lock and is careful to invalidate
* relation's smgr_targblock before the first insertion --- that ensures that
* all insertions will occur into newly added pages and not be intermixed
* with tuples from other transactions. That way, a crash can't risk losing
* any committed data of other transactions. (See heap_insert's comments
* for additional constraints needed for safe usage of this behavior.)
*
* The caller can also provide a BulkInsertState object to optimize many
* insertions into the same relation. This keeps a pin on the current
* insertion target page (to save pin/unpin cycles) and also passes a
* BULKWRITE buffer selection strategy object to the buffer manager.
* Passing NULL for bistate selects the default behavior.
*
* We always try to avoid filling existing pages further than the fillfactor.
* This is OK since this routine is not consulted when updating a tuple and
* keeping it on the same page, which is the scenario fillfactor is meant
* to reserve space for.
*
* ereport(ERROR) is allowed here, so this routine *must* be called
* before any (unlogged) changes are made in buffer pool.
*/
Buffer
RelationGetBufferForTuple(Relation relation, Size len,
Buffer otherBuffer, int options,
BulkInsertState bistate,
Buffer *vmbuffer, Buffer *vmbuffer_other)
{
bool use_fsm = !(options & HEAP_INSERT_SKIP_FSM);
Buffer buffer = InvalidBuffer;
Page page;
Size pageFreeSpace,
saveFreeSpace;
BlockNumber targetBlock,
otherBlock;
bool needLock;
len = MAXALIGN(len); /* be conservative */
/* Bulk insert is not supported for updates, only inserts. */
Assert(otherBuffer == InvalidBuffer || !bistate);
/*
* 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 %lu, maximum size %lu",
(unsigned long) len,
(unsigned long) MaxHeapTupleSize)));
/* Compute desired extra freespace due to fillfactor option */
saveFreeSpace = RelationGetTargetPageFreeSpace(relation,
HEAP_DEFAULT_FILLFACTOR);
if (otherBuffer != InvalidBuffer)
otherBlock = BufferGetBlockNumber(otherBuffer);
else
otherBlock = InvalidBlockNumber; /* just to keep compiler quiet */
/*
* We first try to put the tuple on the same page we last inserted a tuple
* on, as cached in the BulkInsertState or relcache entry. If that
* doesn't work, we ask the Free Space Map to locate a suitable page.
* Since the FSM's info might be out of date, we have to be prepared to
* loop around and retry multiple times. (To insure this isn't an infinite
* loop, we must update the FSM with the correct amount of free space on
* each page that proves not to be suitable.) If the FSM has no record of
* a page with enough free space, we give up and extend the relation.
*
* When use_fsm is false, we either put the tuple onto the existing target
* page or extend the relation.
*/
if (len + saveFreeSpace > MaxHeapTupleSize)
{
/* can't fit, don't bother asking FSM */
targetBlock = InvalidBlockNumber;
use_fsm = false;
}
else if (bistate && bistate->current_buf != InvalidBuffer)
targetBlock = BufferGetBlockNumber(bistate->current_buf);
else
targetBlock = RelationGetTargetBlock(relation);
if (targetBlock == InvalidBlockNumber && use_fsm)
{
/*
* We have no cached target page, so ask the FSM for an initial
* target.
*/
targetBlock = GetPageWithFreeSpace(relation, len + saveFreeSpace);
/*
* If the FSM knows nothing of the rel, try the last page before we
* give up and extend. This avoids one-tuple-per-page syndrome during
* bootstrapping or in a recently-started system.
*/
if (targetBlock == InvalidBlockNumber)
{
BlockNumber nblocks = RelationGetNumberOfBlocks(relation);
if (nblocks > 0)
targetBlock = nblocks - 1;
}
}
while (targetBlock != InvalidBlockNumber)
{
/*
* Read and exclusive-lock the target block, as well as the other
* block if one was given, taking suitable care with lock ordering and
* the possibility they are the same block.
*
* If the page-level all-visible flag is set, caller will need to
* clear both that and the corresponding visibility map bit. However,
* by the time we return, we'll have x-locked the buffer, and we don't
* want to do any I/O while in that state. So we check the bit here
* before taking the lock, and pin the page if it appears necessary.
* Checking without the lock creates a risk of getting the wrong
* answer, so we'll have to recheck after acquiring the lock.
*/
if (otherBuffer == InvalidBuffer)
{
/* easy case */
buffer = ReadBufferBI(relation, targetBlock, bistate);
if (PageIsAllVisible(BufferGetPage(buffer)))
visibilitymap_pin(relation, targetBlock, vmbuffer);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
}
else if (otherBlock == targetBlock)
{
/* also easy case */
buffer = otherBuffer;
if (PageIsAllVisible(BufferGetPage(buffer)))
visibilitymap_pin(relation, targetBlock, vmbuffer);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
}
else if (otherBlock < targetBlock)
{
/* lock other buffer first */
buffer = ReadBuffer(relation, targetBlock);
if (PageIsAllVisible(BufferGetPage(buffer)))
visibilitymap_pin(relation, targetBlock, vmbuffer);
LockBuffer(otherBuffer, BUFFER_LOCK_EXCLUSIVE);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
}
else
{
/* lock target buffer first */
buffer = ReadBuffer(relation, targetBlock);
if (PageIsAllVisible(BufferGetPage(buffer)))
visibilitymap_pin(relation, targetBlock, vmbuffer);
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
LockBuffer(otherBuffer, BUFFER_LOCK_EXCLUSIVE);
}
/*
* We now have the target page (and the other buffer, if any) pinned
* and locked. However, since our initial PageIsAllVisible checks
* were performed before acquiring the lock, the results might now be
* out of date, either for the selected victim buffer, or for the
* other buffer passed by the caller. In that case, we'll need to
* give up our locks, go get the pin(s) we failed to get earlier, and
* re-lock. That's pretty painful, but hopefully shouldn't happen
* often.
*
* Note that there's a small possibility that we didn't pin the page
* above but still have the correct page pinned anyway, either because
* we've already made a previous pass through this loop, or because
* caller passed us the right page anyway.
*
* Note also that it's possible that by the time we get the pin and
* retake the buffer locks, the visibility map bit will have been
* cleared by some other backend anyway. In that case, we'll have
* done a bit of extra work for no gain, but there's no real harm
* done.
*/
if (otherBuffer == InvalidBuffer || buffer <= otherBuffer)
GetVisibilityMapPins(relation, buffer, otherBuffer,
targetBlock, otherBlock, vmbuffer,
vmbuffer_other);
else
GetVisibilityMapPins(relation, otherBuffer, buffer,
otherBlock, targetBlock, vmbuffer_other,
vmbuffer);
/*
* Now we can check to see if there's enough free space here. If so,
* we're done.
*/
page = BufferGetPage(buffer);
pageFreeSpace = PageGetHeapFreeSpace(page);
if (len + saveFreeSpace <= pageFreeSpace)
{
/* use this page as future insert target, too */
RelationSetTargetBlock(relation, targetBlock);
return buffer;
}
/*
* Not enough space, so we must give up our page locks and pin (if
* any) and prepare to look elsewhere. We don't care which order we
* unlock the two buffers in, so this can be slightly simpler than the
* code above.
*/
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
if (otherBuffer == InvalidBuffer)
ReleaseBuffer(buffer);
else if (otherBlock != targetBlock)
{
LockBuffer(otherBuffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
}
/* Without FSM, always fall out of the loop and extend */
if (!use_fsm)
break;
/*
* Update FSM as to condition of this page, and ask for another page
* to try.
*/
targetBlock = RecordAndGetPageWithFreeSpace(relation,
targetBlock,
pageFreeSpace,
len + saveFreeSpace);
}
/*
* Have to extend the relation.
*
* We have to use a lock to ensure no one else is extending the rel at the
* same time, else we will both try to initialize the same new page. We
* can skip locking for new or temp relations, however, since no one else
* could be accessing them.
*/
needLock = !RELATION_IS_LOCAL(relation);
if (needLock)
LockRelationForExtension(relation, ExclusiveLock);
/*
* XXX This does an lseek - rather expensive - but at the moment it is the
* only way to accurately determine how many blocks are in a relation. Is
* it worth keeping an accurate file length in shared memory someplace,
* rather than relying on the kernel to do it for us?
*/
buffer = ReadBufferBI(relation, P_NEW, bistate);
/*
* We can be certain that locking the otherBuffer first is OK, since it
* must have a lower page number.
*/
if (otherBuffer != InvalidBuffer)
LockBuffer(otherBuffer, BUFFER_LOCK_EXCLUSIVE);
/*
* Now acquire lock on the new page.
*/
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
/*
* Release the file-extension lock; it's now OK for someone else to extend
* the relation some more. Note that we cannot release this lock before
* we have buffer lock on the new page, or we risk a race condition
* against vacuumlazy.c --- see comments therein.
*/
if (needLock)
UnlockRelationForExtension(relation, ExclusiveLock);
/*
* We need to initialize the empty new page. Double-check that it really
* is empty (this should never happen, but if it does we don't want to
* risk wiping out valid data).
*/
page = BufferGetPage(buffer);
if (!PageIsNew(page))
elog(ERROR, "page %u of relation \"%s\" should be empty but is not",
BufferGetBlockNumber(buffer),
RelationGetRelationName(relation));
PageInit(page, BufferGetPageSize(buffer), 0);
if (len > PageGetHeapFreeSpace(page))
{
/* We should not get here given the test at the top */
elog(PANIC, "tuple is too big: size %lu", (unsigned long) len);
}
/*
* Remember the new page as our target for future insertions.
*
* XXX should we enter the new page into the free space map immediately,
* or just keep it for this backend's exclusive use in the short run
* (until VACUUM sees it)? Seems to depend on whether you expect the
* current backend to make more insertions or not, which is probably a
* good bet most of the time. So for now, don't add it to FSM yet.
*/
RelationSetTargetBlock(relation, BufferGetBlockNumber(buffer));
return buffer;
}
/*
* Return a pinned and exclusively locked buffer which can be used to insert an
* index item of size itemsz (caller must ensure not to request sizes
* impossible to fulfill). If oldbuf is a valid buffer, it is also locked (in
* an order determined to avoid deadlocks.)
*
* If we find that the old page is no longer a regular index page (because
* of a revmap extension), the old buffer is unlocked and we return
* InvalidBuffer.
*
* If there's no existing page with enough free space to accommodate the new
* item, the relation is extended. If this happens, *extended is set to true,
* and it is the caller's responsibility to initialize the page (and WAL-log
* that fact) prior to use.
*
* Note that in some corner cases it is possible for this routine to extend the
* relation and then not return the buffer. It is this routine's
* responsibility to WAL-log the page initialization and to record the page in
* FSM if that happens. Such a buffer may later be reused by this routine.
*/
static Buffer
brin_getinsertbuffer(Relation irel, Buffer oldbuf, Size itemsz,
bool *extended)
{
BlockNumber oldblk;
BlockNumber newblk;
Page page;
int freespace;
/* callers must have checked */
Assert(itemsz <= BrinMaxItemSize);
*extended = false;
if (BufferIsValid(oldbuf))
oldblk = BufferGetBlockNumber(oldbuf);
else
oldblk = InvalidBlockNumber;
/*
* Loop until we find a page with sufficient free space. By the time we
* return to caller out of this loop, both buffers are valid and locked;
* if we have to restart here, neither buffer is locked and buf is not a
* pinned buffer.
*/
newblk = RelationGetTargetBlock(irel);
if (newblk == InvalidBlockNumber)
newblk = GetPageWithFreeSpace(irel, itemsz);
for (;;)
{
Buffer buf;
bool extensionLockHeld = false;
CHECK_FOR_INTERRUPTS();
if (newblk == InvalidBlockNumber)
{
/*
* There's not enough free space in any existing index page,
* according to the FSM: extend the relation to obtain a shiny new
* page.
*/
if (!RELATION_IS_LOCAL(irel))
{
LockRelationForExtension(irel, ExclusiveLock);
extensionLockHeld = true;
}
buf = ReadBuffer(irel, P_NEW);
newblk = BufferGetBlockNumber(buf);
*extended = true;
BRIN_elog((DEBUG2, "brin_getinsertbuffer: extending to page %u",
BufferGetBlockNumber(buf)));
}
else if (newblk == oldblk)
{
/*
* There's an odd corner-case here where the FSM is out-of-date,
* and gave us the old page.
*/
buf = oldbuf;
}
else
{
buf = ReadBuffer(irel, newblk);
}
/*
* We lock the old buffer first, if it's earlier than the new one; but
* before we do, we need to check that it hasn't been turned into a
* revmap page concurrently; if we detect that it happened, give up
* and tell caller to start over.
*/
if (BufferIsValid(oldbuf) && oldblk < newblk)
{
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
if (!BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)))
{
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
/*
* It is possible that the new page was obtained from
* extending the relation. In that case, we must be sure to
* record it in the FSM before leaving, because otherwise the
* space would be lost forever. However, we cannot let an
* uninitialized page get in the FSM, so we need to initialize
* it first.
*/
if (*extended)
{
brin_initialize_empty_new_buffer(irel, buf);
/* shouldn't matter, but don't confuse caller */
*extended = false;
}
if (extensionLockHeld)
UnlockRelationForExtension(irel, ExclusiveLock);
ReleaseBuffer(buf);
return InvalidBuffer;
}
}
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
if (extensionLockHeld)
UnlockRelationForExtension(irel, ExclusiveLock);
page = BufferGetPage(buf);
/*
* We have a new buffer to insert into. Check that the new page has
* enough free space, and return it if it does; otherwise start over.
* Note that we allow for the FSM to be out of date here, and in that
* case we update it and move on.
*
* (br_page_get_freespace also checks that the FSM didn't hand us a
* page that has since been repurposed for the revmap.)
*/
freespace = *extended ?
BrinMaxItemSize : br_page_get_freespace(page);
if (freespace >= itemsz)
{
RelationSetTargetBlock(irel, BufferGetBlockNumber(buf));
/*
* Since the target block specification can get lost on cache
* invalidations, make sure we update the more permanent FSM with
* data about it before going away.
*/
if (*extended)
RecordPageWithFreeSpace(irel, BufferGetBlockNumber(buf),
freespace);
/*
* Lock the old buffer if not locked already. Note that in this
* case we know for sure it's a regular page: it's later than the
* new page we just got, which is not a revmap page, and revmap
* pages are always consecutive.
*/
if (BufferIsValid(oldbuf) && oldblk > newblk)
{
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
Assert(BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)));
}
return buf;
}
/* This page is no good. */
/*
* If an entirely new page does not contain enough free space for the
* new item, then surely that item is oversized. Complain loudly; but
* first make sure we initialize the page and record it as free, for
* next time.
*/
if (*extended)
{
brin_initialize_empty_new_buffer(irel, buf);
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("index row size %lu exceeds maximum %lu for index \"%s\"",
(unsigned long) itemsz,
(unsigned long) freespace,
RelationGetRelationName(irel))));
return InvalidBuffer; /* keep compiler quiet */
}
if (newblk != oldblk)
UnlockReleaseBuffer(buf);
if (BufferIsValid(oldbuf) && oldblk <= newblk)
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
newblk = RecordAndGetPageWithFreeSpace(irel, newblk, freespace, itemsz);
}
}
