Beispiel #1
0
/*
 * GetDefaultTablespace -- get the OID of the current default tablespace
 *
 * Temporary objects have different default tablespaces, hence the
 * relpersistence parameter must be specified.
 *
 * May return InvalidOid to indicate "use the database's default tablespace".
 *
 * Note that caller is expected to check appropriate permissions for any
 * result other than InvalidOid.
 *
 * This exists to hide (and possibly optimize the use of) the
 * default_tablespace GUC variable.
 */
Oid
GetDefaultTablespace(char relpersistence)
{
	Oid			result;

	/* The temp-table case is handled elsewhere */
	if (relpersistence == RELPERSISTENCE_TEMP)
	{
		PrepareTempTablespaces();
		return GetNextTempTableSpace();
	}

	/* Fast path for default_tablespace == "" */
	if (default_tablespace == NULL || default_tablespace[0] == '\0')
		return InvalidOid;

	/*
	 * It is tempting to cache this lookup for more speed, but then we would
	 * fail to detect the case where the tablespace was dropped since the GUC
	 * variable was set.  Note also that we don't complain if the value fails
	 * to refer to an existing tablespace; we just silently return InvalidOid,
	 * causing the new object to be created in the database's tablespace.
	 */
	result = get_tablespace_oid(default_tablespace, true);

	/*
	 * Allow explicit specification of database's default tablespace in
	 * default_tablespace without triggering permissions checks.
	 */
	if (result == MyDatabaseTableSpace)
		result = InvalidOid;
	return result;
}
Beispiel #2
0
/*
 * Initialize a space for temporary files that can be opened for read-only
 * access by other backends.  Other backends must attach to it before
 * accessing it.  Associate this SharedFileSet with 'seg'.  Any contained
 * files will be deleted when the last backend detaches.
 *
 * Files will be distributed over the tablespaces configured in
 * temp_tablespaces.
 *
 * Under the covers the set is one or more directories which will eventually
 * be deleted when there are no backends attached.
 */
void
SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
{
	static uint32 counter = 0;

	SpinLockInit(&fileset->mutex);
	fileset->refcnt = 1;
	fileset->creator_pid = MyProcPid;
	fileset->number = counter;
	counter = (counter + 1) % INT_MAX;

	/* Capture the tablespace OIDs so that all backends agree on them. */
	PrepareTempTablespaces();
	fileset->ntablespaces =
		GetTempTablespaces(&fileset->tablespaces[0],
						   lengthof(fileset->tablespaces));
	if (fileset->ntablespaces == 0)
	{
		fileset->tablespaces[0] = DEFAULTTABLESPACE_OID;
		fileset->ntablespaces = 1;
	}

	/* Register our cleanup callback. */
	on_dsm_detach(seg, SharedFileSetOnDetach, PointerGetDatum(fileset));
}
Beispiel #3
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
{
	TSReadPointer *readptr;
	int			i;
	ResourceOwner oldowner;

	state->tuples++;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->current = state->memtupcount;
				}
			}

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				(void) grow_memtuples(state);
				Assert(state->memtupcount < state->memtupsize);
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			state->myfile = BufFileCreateTemp(state->interXact);

			CurrentResourceOwner = oldowner;

			/*
			 * Freeze the decision about whether trailing length words will be
			 * used.  We can't change this choice once data is on tape, even
			 * though callers might drop the requirement.
			 */
			state->backward = (state->eflags & EXEC_FLAG_BACKWARD) != 0;
			state->status = TSS_WRITEFILE;
			dumptuples(state);
			break;
		case TSS_WRITEFILE:

			/*
			 * Update read pointers as needed; see API spec above. Note:
			 * BufFileTell is quite cheap, so not worth trying to avoid
			 * multiple calls.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					BufFileTell(state->myfile,
								&readptr->file,
								&readptr->offset);
				}
			}

			WRITETUP(state, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!state->readptrs[state->activeptr].eof_reached)
				BufFileTell(state->myfile,
							&state->readptrs[state->activeptr].file,
							&state->readptrs[state->activeptr].offset);
			if (BufFileSeek(state->myfile,
							state->writepos_file, state->writepos_offset,
							SEEK_SET) != 0)
				ereport(ERROR,
						(errcode_for_file_access(),
				 errmsg("could not seek in tuplestore temporary file: %m")));
			state->status = TSS_WRITEFILE;

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->file = state->writepos_file;
					readptr->offset = state->writepos_offset;
				}
			}

			WRITETUP(state, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}
Beispiel #4
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, TuplestorePos *pos, void *tuple)
{
	ResourceOwner oldowner;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				/*
				 * See grow_memtuples() in tuplesort.c for the rationale
				 * behind these two tests.
				 */
				if (state->availMem > (long) (state->memtupsize * sizeof(void *)) &&
					(Size) (state->memtupsize * 2) < MaxAllocSize / sizeof(void *))
				{
					FREEMEM(state, GetMemoryChunkSpace(state->memtuples));
					state->memtupsize *= 2;
					state->memtuples = (void **)
						repalloc(state->memtuples,
								 state->memtupsize * sizeof(void *));
					USEMEM(state, GetMemoryChunkSpace(state->memtuples));
				}
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/* If eof_reached, keep read position in sync */
			if (pos->eof_reached)
				pos->current = state->memtupcount;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			{
				char tmpprefix[50];
				snprintf(tmpprefix, 50, "slice%d_tuplestore", currentSliceId);
				state->myfile = BufFileCreateTemp(tmpprefix, state->interXact);
			}

			CurrentResourceOwner = oldowner;

			state->status = TSS_WRITEFILE;
			dumptuples(state, pos);
			break;
		case TSS_WRITEFILE:
			WRITETUP(state, pos, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!pos->eof_reached)
				BufFileTell(state->myfile,
							&pos->readpos_offset);
			if (BufFileSeek(state->myfile,
							pos->writepos_offset,
							SEEK_SET) != 0)
				elog(ERROR, "seek to EOF failed");
			state->status = TSS_WRITEFILE;
			WRITETUP(state, pos, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}
Beispiel #5
0
static void
tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
{
	TSReadPointer *readptr;
	int			i;
	ResourceOwner oldowner;

	switch (state->status)
	{
		case TSS_INMEM:

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->current = state->memtupcount;
				}
			}

			/*
			 * Grow the array as needed.  Note that we try to grow the array
			 * when there is still one free slot remaining --- if we fail,
			 * there'll still be room to store the incoming tuple, and then
			 * we'll switch to tape-based operation.
			 */
			if (state->memtupcount >= state->memtupsize - 1)
			{
				/*
				 * See grow_memtuples() in tuplesort.c for the rationale
				 * behind these two tests.
				 */
				if (state->availMem > (long) (state->memtupsize * sizeof(void *)) &&
					(Size) (state->memtupsize * 2) < MaxAllocSize / sizeof(void *))
				{
					FREEMEM(state, GetMemoryChunkSpace(state->memtuples));
					state->memtupsize *= 2;
					state->memtuples = (void **)
						repalloc(state->memtuples,
								 state->memtupsize * sizeof(void *));
					USEMEM(state, GetMemoryChunkSpace(state->memtuples));
					if (LACKMEM(state))
						elog(ERROR, "unexpected out-of-memory situation in tuplestore");
				}
			}

			/* Stash the tuple in the in-memory array */
			state->memtuples[state->memtupcount++] = tuple;

			/*
			 * Done if we still fit in available memory and have array slots.
			 */
			if (state->memtupcount < state->memtupsize && !LACKMEM(state))
				return;

			/*
			 * Nope; time to switch to tape-based operation.  Make sure that
			 * the temp file(s) are created in suitable temp tablespaces.
			 */
			PrepareTempTablespaces();

			/* associate the file with the store's resource owner */
			oldowner = CurrentResourceOwner;
			CurrentResourceOwner = state->resowner;

			char tmpprefix[50];
			snprintf(tmpprefix, 50, "slice%d_tuplestore", currentSliceId);
			state->myfile = BufFileCreateTemp(tmpprefix, state->interXact);

			CurrentResourceOwner = oldowner;

			/*
			 * Freeze the decision about whether trailing length words will be
			 * used.  We can't change this choice once data is on tape, even
			 * though callers might drop the requirement.
			 */
			state->backward = (state->eflags & EXEC_FLAG_BACKWARD) != 0;
			state->status = TSS_WRITEFILE;
			dumptuples(state);
			break;
		case TSS_WRITEFILE:

			/*
			 * Update read pointers as needed; see API spec above. Note:
			 * BufFileTell is quite cheap, so not worth trying to avoid
			 * multiple calls.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					BufFileTell(state->myfile,
								&readptr->file,
								&readptr->offset);
				}
			}

			WRITETUP(state, tuple);
			break;
		case TSS_READFILE:

			/*
			 * Switch from reading to writing.
			 */
			if (!state->readptrs[state->activeptr].eof_reached)
				BufFileTell(state->myfile,
							&state->readptrs[state->activeptr].file,
							&state->readptrs[state->activeptr].offset);
			if (BufFileSeek(state->myfile,
							state->writepos_file, state->writepos_offset,
							SEEK_SET) != 0)
				elog(ERROR, "tuplestore seek to EOF failed");
			state->status = TSS_WRITEFILE;

			/*
			 * Update read pointers as needed; see API spec above.
			 */
			readptr = state->readptrs;
			for (i = 0; i < state->readptrcount; readptr++, i++)
			{
				if (readptr->eof_reached && i != state->activeptr)
				{
					readptr->eof_reached = false;
					readptr->file = state->writepos_file;
					readptr->offset = state->writepos_offset;
				}
			}

			WRITETUP(state, tuple);
			break;
		default:
			elog(ERROR, "invalid tuplestore state");
			break;
	}
}