Пример #1
0
/* -----------------------------------------------
 * bt_page()
 *
 * Usage: SELECT * FROM bt_page('t1_pkey', 1);
 * -----------------------------------------------
 */
datum_t
bt_page_stats(PG_FUNC_ARGS)
{
	text	   *relname = ARG_TEXT_P(0);
	uint32		blkno = ARG_UINT32(1);
	buf_id_t		buffer;
	struct relation *	rel;
	range_var_n   *relrv;
	datum_t		result;
	struct heap_tuple *	tuple;
	struct tuple *tupleDesc;
	int		j;
	char	   *values[11];
	BTPageStat	stat;

	if (!superuser())
		ereport(ERROR,
				(errcode(E_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pageinspect functions"))));

	relrv = nl_to_range_var(textToQualifiedNameList(relname));
	rel = relation_openrv(relrv, ACCESS_SHR_LOCK);

	if (!IS_INDEX(rel) || !IS_BTREE(rel))
		elog(ERROR, "relation \"%s\" is not a btree index",
			 REL_NAME(rel));

	/*
	 * Reject attempts to read non-local temporary relations; we would be
	 * likely to get wrong data since we have no visibility into the owning
	 * session's local buffers.
	 */
	if (REL_IS_OTHER_TMP(rel))
		ereport(ERROR,
				(errcode(E_FEATURE_NOT_SUPPORTED),
				 errmsg("cannot access temporary tables of other sessions")));

	if (blkno == 0)
		elog(ERROR, "block 0 is a meta page");

	CHECK_RELATION_BLOCK_RANGE(rel, blkno);

	buffer = read_buf(rel, blkno);

	/* keep compiler quiet */
	stat.btpo_prev = stat.btpo_next = INVALID_BLK_NR;
	stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;

	GetBTPageStatistics(blkno, buffer, &stat);

	/* Build a tuple descriptor for our result type */
	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
		elog(ERROR, "return type must be a row type");

	j = 0;
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.blkno);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%c", stat.type);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.live_items);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.dead_items);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.avg_item_size);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.page_size);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.free_size);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.btpo_prev);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.btpo_next);
	values[j] = palloc(32);
	if (stat.type == 'd')
		snprintf(values[j++], 32, "%d", stat.btpo.xact);
	else
		snprintf(values[j++], 32, "%d", stat.btpo.level);
	values[j] = palloc(32);
	snprintf(values[j++], 32, "%d", stat.btpo_flags);

	tuple = build_tuple_from_cstrings(TupleDescGetAttInMetadata(tupleDesc),
								   values);

	result = HeapTupleGetDatum(tuple);

	release_buf(buffer);

	relation_close(rel, ACCESS_SHR_LOCK);

	RET_DATUM(result);
}
Пример #2
0
datum_t
bt_page_items(PG_FUNC_ARGS)
{
	text	   *relname = ARG_TEXT_P(0);
	uint32		blkno = ARG_UINT32(1);
	datum_t		result;
	char	   *values[6];
	struct heap_tuple *	tuple;
	struct fcall_ctx *fctx;
	struct mctx * mctx;
	struct user_args *uargs;

	if (!superuser())
		ereport(ERROR,
				(errcode(E_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pageinspect functions"))));

	if (SRF_IS_FIRSTCALL())
	{
		range_var_n   *relrv;
		struct relation *	rel;
		buf_id_t		buffer;
		struct bt_page_opaque * opaque;
		struct tuple *	tupleDesc;

		fctx = SRF_FIRSTCALL_INIT();

		relrv = nl_to_range_var(textToQualifiedNameList(relname));
		rel = relation_openrv(relrv, ACCESS_SHR_LOCK);

		if (!IS_INDEX(rel) || !IS_BTREE(rel))
			elog(ERROR, "relation \"%s\" is not a btree index",
				 REL_NAME(rel));

		/*
		 * Reject attempts to read non-local temporary relations; we would be
		 * likely to get wrong data since we have no visibility into the
		 * owning session's local buffers.
		 */
		if (REL_IS_OTHER_TMP(rel))
			ereport(ERROR,
					(errcode(E_FEATURE_NOT_SUPPORTED),
				errmsg("cannot access temporary tables of other sessions")));

		if (blkno == 0)
			elog(ERROR, "block 0 is a meta page");

		CHECK_RELATION_BLOCK_RANGE(rel, blkno);

		buffer = read_buf(rel, blkno);

		/*
		 * We copy the page into local storage to avoid holding pin on the
		 * buffer longer than we must, and possibly failing to release it at
		 * all if the calling query doesn't fetch all rows.
		 */
		mctx = mctx_switch(fctx->multi_call_memory_ctx);

		uargs = palloc(sizeof(struct user_args));

		uargs->page = palloc(BLK_SZ);
		memcpy(uargs->page, BUF_PAGE(buffer), BLK_SZ);

		release_buf(buffer);
		relation_close(rel, ACCESS_SHR_LOCK);

		uargs->offset = FIRST_ITEM_ID;

		opaque = (struct bt_page_opaque *) PAGE_SPECIAL_PTR(uargs->page);

		if (P_ISDELETED(opaque))
			elog(NOTICE, "page is deleted");

		fctx->max_calls = PAGE_MAX_ITEM_ID(uargs->page);

		/* Build a tuple descriptor for our result type */
		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
			elog(ERROR, "return type must be a row type");

		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);

		fctx->user_fctx = uargs;

		mctx_switch(mctx);
	}

	fctx = SRF_PERCALL_SETUP();
	uargs = fctx->user_fctx;

	if (fctx->call_cntr < fctx->max_calls)
	{
		struct item_id *		id;
		struct index_tuple *	itup;
		int			j;
		int			off;
		int			dlen;
		char	   *dump;
		char	   *ptr;

		id = PAGE_ITEM_ID(uargs->page, uargs->offset);

		if (!ITEMID_VALID(id))
			elog(ERROR, "invalid ItemId");

		itup = (struct index_tuple *) PAGE_GET_ITEM(uargs->page, id);

		j = 0;
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", uargs->offset);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "(%u,%u)",
				 BLK_ID_TO_BLK_NR(&(itup->t_tid.ip_blkid)),
				 itup->t_tid.ip_posid);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", (int) INDEX_TUPLE_SZ(itup));
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%c", INDEX_TUPLE_HAS_NULLS(itup) ? 't' : 'f');
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%c", INDEX_TUPLE_HAS_VAR(itup) ? 't' : 'f');

		ptr = (char *) itup + INDEX_TUPLE_DATA_OFFSET(itup->t_info);
		dlen = INDEX_TUPLE_SZ(itup) - INDEX_TUPLE_DATA_OFFSET(itup->t_info);
		dump = pzalloc(dlen * 3 + 1);
		values[j] = dump;
		for (off = 0; off < dlen; off++)
		{
			if (off > 0)
				*dump++ = ' ';
			sprintf(dump, "%02x", *(ptr + off) & 0xff);
			dump += 2;
		}

		tuple = build_tuple_from_cstrings(fctx->attinmeta, values);
		result = HeapTupleGetDatum(tuple);

		uargs->offset = uargs->offset + 1;

		SRF_RETURN_NEXT(fctx, result);
	}
	else
	{
		pfree(uargs->page);
		pfree(uargs);
		SRF_RETURN_DONE(fctx);
	}
}
Пример #3
0
/*-------------------------------------------------------
 * bt_page_items()
 *
 * Get IndexTupleData set in a btree page
 *
 * Usage: SELECT * FROM bt_page_items('t1_pkey', 1);
 *-------------------------------------------------------
 */
Datum
bt_page_items(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_PP(0);
	uint32		blkno = PG_GETARG_UINT32(1);
	Datum		result;
	FuncCallContext *fctx;
	MemoryContext mctx;
	struct user_args *uargs;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pageinspect functions"))));

	if (SRF_IS_FIRSTCALL())
	{
		RangeVar   *relrv;
		Relation	rel;
		Buffer		buffer;
		BTPageOpaque opaque;
		TupleDesc	tupleDesc;

		fctx = SRF_FIRSTCALL_INIT();

		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		rel = relation_openrv(relrv, AccessShareLock);

		if (!IS_INDEX(rel) || !IS_BTREE(rel))
			elog(ERROR, "relation \"%s\" is not a btree index",
				 RelationGetRelationName(rel));

		/*
		 * Reject attempts to read non-local temporary relations; we would be
		 * likely to get wrong data since we have no visibility into the
		 * owning session's local buffers.
		 */
		if (RELATION_IS_OTHER_TEMP(rel))
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				errmsg("cannot access temporary tables of other sessions")));

		if (blkno == 0)
			elog(ERROR, "block 0 is a meta page");

		CHECK_RELATION_BLOCK_RANGE(rel, blkno);

		buffer = ReadBuffer(rel, blkno);
		LockBuffer(buffer, BUFFER_LOCK_SHARE);

		/*
		 * We copy the page into local storage to avoid holding pin on the
		 * buffer longer than we must, and possibly failing to release it at
		 * all if the calling query doesn't fetch all rows.
		 */
		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);

		uargs = palloc(sizeof(struct user_args));

		uargs->page = palloc(BLCKSZ);
		memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);

		UnlockReleaseBuffer(buffer);
		relation_close(rel, AccessShareLock);

		uargs->offset = FirstOffsetNumber;

		opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);

		if (P_ISDELETED(opaque))
			elog(NOTICE, "page is deleted");

		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);

		/* Build a tuple descriptor for our result type */
		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
			elog(ERROR, "return type must be a row type");

		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);

		fctx->user_fctx = uargs;

		MemoryContextSwitchTo(mctx);
	}

	fctx = SRF_PERCALL_SETUP();
	uargs = fctx->user_fctx;

	if (fctx->call_cntr < fctx->max_calls)
	{
		result = bt_page_print_tuples(fctx, uargs->page, uargs->offset);
		uargs->offset++;
		SRF_RETURN_NEXT(fctx, result);
	}
	else
	{
		pfree(uargs->page);
		pfree(uargs);
		SRF_RETURN_DONE(fctx);
	}
}
Пример #4
0
/* -----------------------------------------------
 * bt_page_stats()
 *
 * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1);
 * -----------------------------------------------
 */
Datum
bt_page_stats(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_PP(0);
	uint32		blkno = PG_GETARG_UINT32(1);
	Buffer		buffer;
	Relation	rel;
	RangeVar   *relrv;
	Datum		result;
	HeapTuple	tuple;
	TupleDesc	tupleDesc;
	int			j;
	char	   *values[11];
	BTPageStat	stat;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pageinspect functions"))));

	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
	rel = relation_openrv(relrv, AccessShareLock);

	if (!IS_INDEX(rel) || !IS_BTREE(rel))
		elog(ERROR, "relation \"%s\" is not a btree index",
			 RelationGetRelationName(rel));

	/*
	 * Reject attempts to read non-local temporary relations; we would be
	 * likely to get wrong data since we have no visibility into the owning
	 * session's local buffers.
	 */
	if (RELATION_IS_OTHER_TEMP(rel))
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("cannot access temporary tables of other sessions")));

	if (blkno == 0)
		elog(ERROR, "block 0 is a meta page");

	CHECK_RELATION_BLOCK_RANGE(rel, blkno);

	buffer = ReadBuffer(rel, blkno);
	LockBuffer(buffer, BUFFER_LOCK_SHARE);

	/* keep compiler quiet */
	stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
	stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;

	GetBTPageStatistics(blkno, buffer, &stat);

	UnlockReleaseBuffer(buffer);
	relation_close(rel, AccessShareLock);

	/* Build a tuple descriptor for our result type */
	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
		elog(ERROR, "return type must be a row type");

	j = 0;
	values[j++] = psprintf("%d", stat.blkno);
	values[j++] = psprintf("%c", stat.type);
	values[j++] = psprintf("%d", stat.live_items);
	values[j++] = psprintf("%d", stat.dead_items);
	values[j++] = psprintf("%d", stat.avg_item_size);
	values[j++] = psprintf("%d", stat.page_size);
	values[j++] = psprintf("%d", stat.free_size);
	values[j++] = psprintf("%d", stat.btpo_prev);
	values[j++] = psprintf("%d", stat.btpo_next);
	values[j++] = psprintf("%d", (stat.type == 'd') ? stat.btpo.xact : stat.btpo.level);
	values[j++] = psprintf("%d", stat.btpo_flags);

	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
								   values);

	result = HeapTupleGetDatum(tuple);

	PG_RETURN_DATUM(result);
}
Пример #5
0
Datum
bt_page_items(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_P(0);
	uint32		blkno = PG_GETARG_UINT32(1);
	Datum		result;
	char	   *values[6];
	HeapTuple	tuple;
	FuncCallContext *fctx;
	MemoryContext mctx;
	struct user_args *uargs;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pageinspect functions"))));

	if (SRF_IS_FIRSTCALL())
	{
		RangeVar   *relrv;
		Relation	rel;
		Buffer		buffer;
		BTPageOpaque opaque;
		TupleDesc	tupleDesc;

		fctx = SRF_FIRSTCALL_INIT();

		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		rel = relation_openrv(relrv, AccessShareLock);

		if (!IS_INDEX(rel) || !IS_BTREE(rel))
			elog(ERROR, "relation \"%s\" is not a btree index",
				 RelationGetRelationName(rel));

		/*
		 * Reject attempts to read non-local temporary relations; we would be
		 * likely to get wrong data since we have no visibility into the
		 * owning session's local buffers.
		 */
		if (RELATION_IS_OTHER_TEMP(rel))
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				errmsg("cannot access temporary tables of other sessions")));

		if (blkno == 0)
			elog(ERROR, "block 0 is a meta page");

		CHECK_RELATION_BLOCK_RANGE(rel, blkno);

		buffer = ReadBuffer(rel, blkno);
		LockBuffer(buffer, BUFFER_LOCK_SHARE);

		/*
		 * We copy the page into local storage to avoid holding pin on the
		 * buffer longer than we must, and possibly failing to release it at
		 * all if the calling query doesn't fetch all rows.
		 */
		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);

		uargs = palloc(sizeof(struct user_args));

		uargs->page = palloc(BLCKSZ);
		memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);

		UnlockReleaseBuffer(buffer);
		relation_close(rel, AccessShareLock);

		uargs->offset = FirstOffsetNumber;

		opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);

		if (P_ISDELETED(opaque))
			elog(NOTICE, "page is deleted");

		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);

		/* Build a tuple descriptor for our result type */
		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
			elog(ERROR, "return type must be a row type");

		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);

		fctx->user_fctx = uargs;

		MemoryContextSwitchTo(mctx);
	}

	fctx = SRF_PERCALL_SETUP();
	uargs = fctx->user_fctx;

	if (fctx->call_cntr < fctx->max_calls)
	{
		ItemId		id;
		IndexTuple	itup;
		int			j;
		int			off;
		int			dlen;
		char	   *dump;
		char	   *ptr;

		id = PageGetItemId(uargs->page, uargs->offset);

		if (!ItemIdIsValid(id))
			elog(ERROR, "invalid ItemId");

		itup = (IndexTuple) PageGetItem(uargs->page, id);

		j = 0;
		values[j++] = psprintf("%d", uargs->offset);
		values[j++] = psprintf("(%u,%u)",
							   BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid)),
							   itup->t_tid.ip_posid);
		values[j++] = psprintf("%d", (int) IndexTupleSize(itup));
		values[j++] = psprintf("%c", IndexTupleHasNulls(itup) ? 't' : 'f');
		values[j++] = psprintf("%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');

		ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
		dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
		dump = palloc0(dlen * 3 + 1);
		values[j] = dump;
		for (off = 0; off < dlen; off++)
		{
			if (off > 0)
				*dump++ = ' ';
			sprintf(dump, "%02x", *(ptr + off) & 0xff);
			dump += 2;
		}

		tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
		result = HeapTupleGetDatum(tuple);

		uargs->offset = uargs->offset + 1;

		SRF_RETURN_NEXT(fctx, result);
	}
	else
	{
		pfree(uargs->page);
		pfree(uargs);
		SRF_RETURN_DONE(fctx);
	}
}
Пример #6
0
Datum
bt_page_items(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_P(0);
	uint32		blkno = PG_GETARG_UINT32(1);

	RangeVar   *relrv;
	Datum		result;
	char	   *values[BTPAGEITEMS_NCOLUMNS];
	BTPageOpaque opaque;
	HeapTuple	tuple;
	ItemId		id;

	FuncCallContext *fctx;
	MemoryContext mctx;
	struct user_args *uargs = NULL;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pgstattuple functions"))));

	if (blkno == 0)
		elog(ERROR, "Block 0 is a meta page.");

	if (SRF_IS_FIRSTCALL())
	{
		fctx = SRF_FIRSTCALL_INIT();
		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);

		uargs = palloc(sizeof(struct user_args));

		uargs->tupd = RelationNameGetTupleDesc(BTPAGEITEMS_TYPE);
		uargs->offset = FirstOffsetNumber;

		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		uargs->rel = relation_openrv(relrv, AccessShareLock);

		CHECK_RELATION_BLOCK_RANGE(uargs->rel, blkno);

		uargs->buffer = ReadBuffer(uargs->rel, blkno);

		if (!IS_INDEX(uargs->rel) || !IS_BTREE(uargs->rel))
			elog(ERROR, "bt_page_items() can be used only on b-tree index.");

		uargs->page = BufferGetPage(uargs->buffer);

		opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);

		if (P_ISDELETED(opaque))
			elog(NOTICE, "bt_page_items(): this page is deleted.");

		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
		fctx->user_fctx = uargs;

		MemoryContextSwitchTo(mctx);
	}

	fctx = SRF_PERCALL_SETUP();
	uargs = fctx->user_fctx;

	if (fctx->call_cntr < fctx->max_calls)
	{
		IndexTuple	itup;

		id = PageGetItemId(uargs->page, uargs->offset);

		if (!ItemIdIsValid(id))
			elog(ERROR, "Invalid ItemId.");

		itup = (IndexTuple) PageGetItem(uargs->page, id);

		{
			int			j = 0;

			BlockNumber blkno = BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid));

			values[j] = palloc(32);
			snprintf(values[j++], 32, "%d", uargs->offset);
			values[j] = palloc(32);
			snprintf(values[j++], 32, "(%u,%u)", blkno, itup->t_tid.ip_posid);
			values[j] = palloc(32);
			snprintf(values[j++], 32, "%d", (int) IndexTupleSize(itup));
			values[j] = palloc(32);
			snprintf(values[j++], 32, "%c", IndexTupleHasNulls(itup) ? 't' : 'f');
			values[j] = palloc(32);
			snprintf(values[j++], 32, "%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');

			{
				int			off;
				char	   *dump;
				char	   *ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);

				dump = palloc(IndexTupleSize(itup) * 3);
				memset(dump, 0, IndexTupleSize(itup) * 3);

				for (off = 0;
					 off < IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
					 off++)
				{
					if (dump[0] == '\0')
						sprintf(dump, "%02x", *(ptr + off) & 0xff);
					else
					{
						char		buf[4];

						sprintf(buf, " %02x", *(ptr + off) & 0xff);
						strcat(dump, buf);
					}
				}
				values[j] = dump;
			}

			tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(uargs->tupd), values);
			result = TupleGetDatum(TupleDescGetSlot(uargs->tupd), tuple);
		}

		uargs->offset = uargs->offset + 1;

		SRF_RETURN_NEXT(fctx, result);
	}
	else
	{
		ReleaseBuffer(uargs->buffer);
		relation_close(uargs->rel, AccessShareLock);

		SRF_RETURN_DONE(fctx);
	}
}
Пример #7
0
/* -----------------------------------------------
 * bt_page()
 *
 * Usage: SELECT * FROM bt_page('t1_pkey', 0);
 * -----------------------------------------------
 */
Datum
bt_page_stats(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_P(0);
	uint32		blkno = PG_GETARG_UINT32(1);
	Buffer		buffer;

	Relation	rel;
	RangeVar   *relrv;
	Datum		result;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to use pgstattuple functions"))));

	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
	rel = relation_openrv(relrv, AccessShareLock);

	CHECK_RELATION_BLOCK_RANGE(rel, blkno);

	buffer = ReadBuffer(rel, blkno);

	if (!IS_INDEX(rel) || !IS_BTREE(rel))
		elog(ERROR, "bt_page_stats() can be used only on b-tree index.");

	if (blkno == 0)
		elog(ERROR, "Block 0 is a meta page.");

	{
		HeapTuple	tuple;
		TupleDesc	tupleDesc;
		int			j;
		char	   *values[BTPAGESTATS_NCOLUMNS];

		BTPageStat	stat;

		GetBTPageStatistics(blkno, buffer, &stat);

		tupleDesc = RelationNameGetTupleDesc(BTPAGESTATS_TYPE);

		j = 0;
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.blkno);

		values[j] = palloc(32);
		snprintf(values[j++], 32, "%c", stat.type);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.live_items);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.dead_items);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.avg_item_size);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.page_size);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.free_size);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.btpo_prev);
		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.btpo_next);

		values[j] = palloc(32);
		if (stat.type == 'd')
			snprintf(values[j++], 32, "%d", stat.btpo.xact);
		else
			snprintf(values[j++], 32, "%d", stat.btpo.level);

		values[j] = palloc(32);
		snprintf(values[j++], 32, "%d", stat.btpo_flags);

		tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
									   values);

		result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple);
	}

	ReleaseBuffer(buffer);

	relation_close(rel, AccessShareLock);

	PG_RETURN_DATUM(result);
}