Ejemplo n.º 1
0
/*
 * pg_prewarm(regclass, mode text, fork text,
 *			  first_block int8, last_block int8)
 *
 * The first argument is the relation to be prewarmed; the second controls
 * how prewarming is done; legal options are 'prefetch', 'read', and 'buffer'.
 * The third is the name of the relation fork to be prewarmed.  The fourth
 * and fifth arguments specify the first and last block to be prewarmed.
 * If the fourth argument is NULL, it will be taken as 0; if the fifth argument
 * is NULL, it will be taken as the number of blocks in the relation.  The
 * return value is the number of blocks successfully prewarmed.
 */
Datum
pg_prewarm(PG_FUNCTION_ARGS)
{
	Oid			relOid;
	text	   *forkName;
	text	   *type;
	int64		first_block;
	int64		last_block;
	int64		nblocks;
	int64		blocks_done = 0;
	int64		block;
	Relation	rel;
	ForkNumber	forkNumber;
	char	   *forkString;
	char	   *ttype;
	PrewarmType ptype;
	AclResult	aclresult;

	/* Basic sanity checking. */
	if (PG_ARGISNULL(0))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("relation cannot be null")));
	relOid = PG_GETARG_OID(0);
	if (PG_ARGISNULL(1))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 (errmsg("prewarm type cannot be null"))));
	type = PG_GETARG_TEXT_P(1);
	ttype = text_to_cstring(type);
	if (strcmp(ttype, "prefetch") == 0)
		ptype = PREWARM_PREFETCH;
	else if (strcmp(ttype, "read") == 0)
		ptype = PREWARM_READ;
	else if (strcmp(ttype, "buffer") == 0)
		ptype = PREWARM_BUFFER;
	else
	{
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("invalid prewarm type"),
				 errhint("Valid prewarm types are \"prefetch\", \"read\", and \"buffer\".")));
		PG_RETURN_INT64(0);		/* Placate compiler. */
	}
	if (PG_ARGISNULL(2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 (errmsg("relation fork cannot be null"))));
	forkName = PG_GETARG_TEXT_P(2);
	forkString = text_to_cstring(forkName);
	forkNumber = forkname_to_number(forkString);

	/* Open relation and check privileges. */
	rel = relation_open(relOid, AccessShareLock);
	aclresult = pg_class_aclcheck(relOid, GetUserId(), ACL_SELECT);
	if (aclresult != ACLCHECK_OK)
		aclcheck_error(aclresult, ACL_KIND_CLASS, get_rel_name(relOid));

	/* Check that the fork exists. */
	RelationOpenSmgr(rel);
	if (!smgrexists(rel->rd_smgr, forkNumber))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("fork \"%s\" does not exist for this relation",
						forkString)));

	/* Validate block numbers, or handle nulls. */
	nblocks = RelationGetNumberOfBlocksInFork(rel, forkNumber);
	if (PG_ARGISNULL(3))
		first_block = 0;
	else
	{
		first_block = PG_GETARG_INT64(3);
		if (first_block < 0 || first_block >= nblocks)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					 errmsg("starting block number must be between 0 and " INT64_FORMAT,
							nblocks - 1)));
	}
	if (PG_ARGISNULL(4))
		last_block = nblocks - 1;
	else
	{
		last_block = PG_GETARG_INT64(4);
		if (last_block < 0 || last_block >= nblocks)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
			errmsg("ending block number must be between 0 and " INT64_FORMAT,
				   nblocks - 1)));
	}

	/* Now we're ready to do the real work. */
	if (ptype == PREWARM_PREFETCH)
	{
#ifdef USE_PREFETCH

		/*
		 * In prefetch mode, we just hint the OS to read the blocks, but we
		 * don't know whether it really does it, and we don't wait for it to
		 * finish.
		 *
		 * It would probably be better to pass our prefetch requests in chunks
		 * of a megabyte or maybe even a whole segment at a time, but there's
		 * no practical way to do that at present without a gross modularity
		 * violation, so we just do this.
		 */
		for (block = first_block; block <= last_block; ++block)
		{
			CHECK_FOR_INTERRUPTS();
			PrefetchBuffer(rel, forkNumber, block);
			++blocks_done;
		}
#else
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("prefetch is not supported by this build")));
#endif
	}
	else if (ptype == PREWARM_READ)
	{
		/*
		 * In read mode, we actually read the blocks, but not into shared
		 * buffers.  This is more portable than prefetch mode (it works
		 * everywhere) and is synchronous.
		 */
		for (block = first_block; block <= last_block; ++block)
		{
			CHECK_FOR_INTERRUPTS();
			smgrread(rel->rd_smgr, forkNumber, block, blockbuffer.data);
			++blocks_done;
		}
	}
	else if (ptype == PREWARM_BUFFER)
	{
		/*
		 * In buffer mode, we actually pull the data into shared_buffers.
		 */
		for (block = first_block; block <= last_block; ++block)
		{
			Buffer		buf;

			CHECK_FOR_INTERRUPTS();
			buf = ReadBufferExtended(rel, forkNumber, block, RBM_NORMAL, NULL);
			ReleaseBuffer(buf);
			++blocks_done;
		}
	}

	/* Close relation, release lock. */
	relation_close(rel, AccessShareLock);

	PG_RETURN_INT64(blocks_done);
}
Ejemplo n.º 2
0
Datum
pgrowlocks(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;
	HeapScanDesc scan;
	HeapTuple	tuple;
	TupleDesc	tupdesc;
	AttInMetadata *attinmeta;
	Datum		result;
	MyData	   *mydata;
	Relation	rel;

	if (SRF_IS_FIRSTCALL())
	{
		text	   *relname;
		RangeVar   *relrv;
		MemoryContext oldcontext;
		AclResult	aclresult;

		funcctx = SRF_FIRSTCALL_INIT();
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

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

		attinmeta = TupleDescGetAttInMetadata(tupdesc);
		funcctx->attinmeta = attinmeta;

		relname = PG_GETARG_TEXT_P(0);
		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		rel = heap_openrv(relrv, AccessShareLock);

		/* check permissions: must have SELECT on table */
		aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
									  ACL_SELECT);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, ACL_KIND_CLASS,
						   RelationGetRelationName(rel));

		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
		mydata = palloc(sizeof(*mydata));
		mydata->rel = rel;
		mydata->scan = scan;
		mydata->ncolumns = tupdesc->natts;
		funcctx->user_fctx = mydata;

		MemoryContextSwitchTo(oldcontext);
	}

	funcctx = SRF_PERCALL_SETUP();
	attinmeta = funcctx->attinmeta;
	mydata = (MyData *) funcctx->user_fctx;
	scan = mydata->scan;

	/* scan the relation */
	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
	{
		/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);

		if (HeapTupleSatisfiesUpdate(rel, tuple->t_data,
									 GetCurrentCommandId(/*false*/),
									 scan->rs_cbuf) == HeapTupleBeingUpdated)
		{

			char	  **values;
			int			i;

			values = (char **) palloc(mydata->ncolumns * sizeof(char *));

			i = 0;
			values[i++] = (char *) DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self));

			if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK)
				values[i++] = pstrdup("Shared");
			else
				values[i++] = pstrdup("Exclusive");
			values[i] = palloc(NCHARS * sizeof(char));
			snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data));
			if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI)
			{
				TransactionId *xids;
				int			nxids;
				int			j;
				int			isValidXid = 0;		/* any valid xid ever exists? */

				values[i++] = pstrdup("true");
				nxids = GetMultiXactIdMembers(HeapTupleHeaderGetXmax(tuple->t_data), &xids);
				if (nxids == -1)
				{
					elog(ERROR, "GetMultiXactIdMembers returns error");
				}

				values[i] = palloc(NCHARS * nxids);
				values[i + 1] = palloc(NCHARS * nxids);
				strcpy(values[i], "{");
				strcpy(values[i + 1], "{");

				for (j = 0; j < nxids; j++)
				{
					char		buf[NCHARS];

					if (TransactionIdIsInProgress(xids[j]))
					{
						if (isValidXid)
						{
							strcat(values[i], ",");
							strcat(values[i + 1], ",");
						}
						snprintf(buf, NCHARS, "%d", xids[j]);
						strcat(values[i], buf);
						snprintf(buf, NCHARS, "%d", BackendXidGetPid(xids[j]));
						strcat(values[i + 1], buf);

						isValidXid = 1;
					}
				}

				strcat(values[i], "}");
				strcat(values[i + 1], "}");
				i++;
			}
			else
			{
				values[i++] = pstrdup("false");
				values[i] = palloc(NCHARS * sizeof(char));
				snprintf(values[i++], NCHARS, "{%d}", HeapTupleHeaderGetXmax(tuple->t_data));

				values[i] = palloc(NCHARS * sizeof(char));
				snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data)));
			}

			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);

			/* build a tuple */
			tuple = BuildTupleFromCStrings(attinmeta, values);

			/* make the tuple into a datum */
			result = HeapTupleGetDatum(tuple);

			/* Clean up */
			for (i = 0; i < mydata->ncolumns; i++)
				pfree(values[i]);
			pfree(values);

			SRF_RETURN_NEXT(funcctx, result);
		}
		else
		{
			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
		}
	}

	heap_endscan(scan);
	heap_close(mydata->rel, AccessShareLock);

	SRF_RETURN_DONE(funcctx);
}
Ejemplo n.º 3
0
/*
 * BuildIndexValueDescription
 *
 * Construct a string describing the contents of an index entry, in the
 * form "(key_name, ...)=(key_value, ...)".  This is currently used
 * for building unique-constraint and exclusion-constraint error messages.
 *
 * Note that if the user does not have permissions to view all of the
 * columns involved then a NULL is returned.  Returning a partial key seems
 * unlikely to be useful and we have no way to know which of the columns the
 * user provided (unlike in ExecBuildSlotValueDescription).
 *
 * The passed-in values/nulls arrays are the "raw" input to the index AM,
 * e.g. results of FormIndexDatum --- this is not necessarily what is stored
 * in the index, but it's what the user perceives to be stored.
 */
char *
BuildIndexValueDescription(Relation indexRelation,
						   Datum *values, bool *isnull)
{
	StringInfoData buf;
	Form_pg_index idxrec;
	HeapTuple	ht_idx;
	int			natts = indexRelation->rd_rel->relnatts;
	int			i;
	int			keyno;
	Oid			indexrelid = RelationGetRelid(indexRelation);
	Oid			indrelid;
	AclResult	aclresult;

	/*
	 * Check permissions- if the user does not have access to view all of the
	 * key columns then return NULL to avoid leaking data.
	 *
	 * First check if RLS is enabled for the relation.  If so, return NULL to
	 * avoid leaking data.
	 *
	 * Next we need to check table-level SELECT access and then, if there is
	 * no access there, check column-level permissions.
	 */

	/*
	 * Fetch the pg_index tuple by the Oid of the index
	 */
	ht_idx = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexrelid));
	if (!HeapTupleIsValid(ht_idx))
		elog(ERROR, "cache lookup failed for index %u", indexrelid);
	idxrec = (Form_pg_index) GETSTRUCT(ht_idx);

	indrelid = idxrec->indrelid;
	Assert(indexrelid == idxrec->indexrelid);

	/* RLS check- if RLS is enabled then we don't return anything. */
	if (check_enable_rls(indrelid, InvalidOid, true) == RLS_ENABLED)
	{
		ReleaseSysCache(ht_idx);
		return NULL;
	}

	/* Table-level SELECT is enough, if the user has it */
	aclresult = pg_class_aclcheck(indrelid, GetUserId(), ACL_SELECT);
	if (aclresult != ACLCHECK_OK)
	{
		/*
		 * No table-level access, so step through the columns in the index and
		 * make sure the user has SELECT rights on all of them.
		 */
		for (keyno = 0; keyno < idxrec->indnatts; keyno++)
		{
			AttrNumber	attnum = idxrec->indkey.values[keyno];

			/*
			 * Note that if attnum == InvalidAttrNumber, then this is an index
			 * based on an expression and we return no detail rather than try
			 * to figure out what column(s) the expression includes and if the
			 * user has SELECT rights on them.
			 */
			if (attnum == InvalidAttrNumber ||
				pg_attribute_aclcheck(indrelid, attnum, GetUserId(),
									  ACL_SELECT) != ACLCHECK_OK)
			{
				/* No access, so clean up and return */
				ReleaseSysCache(ht_idx);
				return NULL;
			}
		}
	}
	ReleaseSysCache(ht_idx);

	initStringInfo(&buf);
	appendStringInfo(&buf, "(%s)=(",
					 pg_get_indexdef_columns(indexrelid, true));

	for (i = 0; i < natts; i++)
	{
		char	   *val;

		if (isnull[i])
			val = "null";
		else
		{
			Oid			foutoid;
			bool		typisvarlena;

			/*
			 * The provided data is not necessarily of the type stored in the
			 * index; rather it is of the index opclass's input type. So look
			 * at rd_opcintype not the index tupdesc.
			 *
			 * Note: this is a bit shaky for opclasses that have pseudotype
			 * input types such as ANYARRAY or RECORD.  Currently, the
			 * typoutput functions associated with the pseudotypes will work
			 * okay, but we might have to try harder in future.
			 */
			getTypeOutputInfo(indexRelation->rd_opcintype[i],
							  &foutoid, &typisvarlena);
			val = OidOutputFunctionCall(foutoid, values[i]);
		}

		if (i > 0)
			appendStringInfoString(&buf, ", ");
		appendStringInfoString(&buf, val);
	}

	appendStringInfoChar(&buf, ')');

	return buf.data;
}
Ejemplo n.º 4
0
Datum
pgrowlocks(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;
	HeapScanDesc scan;
	HeapTuple	tuple;
	TupleDesc	tupdesc;
	AttInMetadata *attinmeta;
	Datum		result;
	MyData	   *mydata;
	Relation	rel;

	if (SRF_IS_FIRSTCALL())
	{
		text	   *relname;
		RangeVar   *relrv;
		MemoryContext oldcontext;
		AclResult	aclresult;

		funcctx = SRF_FIRSTCALL_INIT();
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

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

		attinmeta = TupleDescGetAttInMetadata(tupdesc);
		funcctx->attinmeta = attinmeta;

		relname = PG_GETARG_TEXT_P(0);
		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		rel = heap_openrv(relrv, AccessShareLock);

		/* check permissions: must have SELECT on table */
		aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
									  ACL_SELECT);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, ACL_KIND_CLASS,
						   RelationGetRelationName(rel));

		scan = heap_beginscan(rel, GetActiveSnapshot(), 0, NULL);
		mydata = palloc(sizeof(*mydata));
		mydata->rel = rel;
		mydata->scan = scan;
		mydata->ncolumns = tupdesc->natts;
		funcctx->user_fctx = mydata;

		MemoryContextSwitchTo(oldcontext);
	}

	funcctx = SRF_PERCALL_SETUP();
	attinmeta = funcctx->attinmeta;
	mydata = (MyData *) funcctx->user_fctx;
	scan = mydata->scan;

	/* scan the relation */
	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
	{
		HTSU_Result htsu;
		TransactionId xmax;
		uint16		infomask;

		/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);

		htsu = HeapTupleSatisfiesUpdate(tuple,
										GetCurrentCommandId(false),
										scan->rs_cbuf);
		xmax = HeapTupleHeaderGetRawXmax(tuple->t_data);
		infomask = tuple->t_data->t_infomask;

		/*
		 * a tuple is locked if HTSU returns BeingUpdated, and if it returns
		 * MayBeUpdated but the Xmax is valid and pointing at us.
		 */
		if (htsu == HeapTupleBeingUpdated ||
			(htsu == HeapTupleMayBeUpdated &&
			 !(infomask & HEAP_XMAX_INVALID) &&
			 !(infomask & HEAP_XMAX_IS_MULTI) &&
			 (xmax == GetCurrentTransactionIdIfAny())))
		{
			char	  **values;

			values = (char **) palloc(mydata->ncolumns * sizeof(char *));

			values[Atnum_tid] = (char *) DirectFunctionCall1(tidout,
											PointerGetDatum(&tuple->t_self));

			values[Atnum_xmax] = palloc(NCHARS * sizeof(char));
			snprintf(values[Atnum_xmax], NCHARS, "%d", xmax);
			if (infomask & HEAP_XMAX_IS_MULTI)
			{
				MultiXactMember *members;
				int			nmembers;
				bool		first = true;
				bool		allow_old;

				values[Atnum_ismulti] = pstrdup("true");

				allow_old = !(infomask & HEAP_LOCK_MASK) &&
					(infomask & HEAP_XMAX_LOCK_ONLY);
				nmembers = GetMultiXactIdMembers(xmax, &members, allow_old,
												 false);
				if (nmembers == -1)
				{
					values[Atnum_xids] = "{0}";
					values[Atnum_modes] = "{transient upgrade status}";
					values[Atnum_pids] = "{0}";
				}
				else
				{
					int			j;

					values[Atnum_xids] = palloc(NCHARS * nmembers);
					values[Atnum_modes] = palloc(NCHARS * nmembers);
					values[Atnum_pids] = palloc(NCHARS * nmembers);

					strcpy(values[Atnum_xids], "{");
					strcpy(values[Atnum_modes], "{");
					strcpy(values[Atnum_pids], "{");

					for (j = 0; j < nmembers; j++)
					{
						char		buf[NCHARS];

						if (!first)
						{
							strcat(values[Atnum_xids], ",");
							strcat(values[Atnum_modes], ",");
							strcat(values[Atnum_pids], ",");
						}
						snprintf(buf, NCHARS, "%d", members[j].xid);
						strcat(values[Atnum_xids], buf);
						switch (members[j].status)
						{
							case MultiXactStatusUpdate:
								snprintf(buf, NCHARS, "Update");
								break;
							case MultiXactStatusNoKeyUpdate:
								snprintf(buf, NCHARS, "No Key Update");
								break;
							case MultiXactStatusForUpdate:
								snprintf(buf, NCHARS, "For Update");
								break;
							case MultiXactStatusForNoKeyUpdate:
								snprintf(buf, NCHARS, "For No Key Update");
								break;
							case MultiXactStatusForShare:
								snprintf(buf, NCHARS, "Share");
								break;
							case MultiXactStatusForKeyShare:
								snprintf(buf, NCHARS, "Key Share");
								break;
						}
						strcat(values[Atnum_modes], buf);
						snprintf(buf, NCHARS, "%d",
								 BackendXidGetPid(members[j].xid));
						strcat(values[Atnum_pids], buf);

						first = false;
					}

					strcat(values[Atnum_xids], "}");
					strcat(values[Atnum_modes], "}");
					strcat(values[Atnum_pids], "}");
				}
			}
			else
			{
				values[Atnum_ismulti] = pstrdup("false");

				values[Atnum_xids] = palloc(NCHARS * sizeof(char));
				snprintf(values[Atnum_xids], NCHARS, "{%d}", xmax);

				values[Atnum_modes] = palloc(NCHARS);
				if (infomask & HEAP_XMAX_LOCK_ONLY)
				{
					if (HEAP_XMAX_IS_SHR_LOCKED(infomask))
						snprintf(values[Atnum_modes], NCHARS, "{For Share}");
					else if (HEAP_XMAX_IS_KEYSHR_LOCKED(infomask))
						snprintf(values[Atnum_modes], NCHARS, "{For Key Share}");
					else if (HEAP_XMAX_IS_EXCL_LOCKED(infomask))
					{
						if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
							snprintf(values[Atnum_modes], NCHARS, "{For Update}");
						else
							snprintf(values[Atnum_modes], NCHARS, "{For No Key Update}");
					}
					else
						/* neither keyshare nor exclusive bit it set */
						snprintf(values[Atnum_modes], NCHARS,
								 "{transient upgrade status}");
				}
				else
				{
					if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
						snprintf(values[Atnum_modes], NCHARS, "{Update}");
					else
						snprintf(values[Atnum_modes], NCHARS, "{No Key Update}");
				}

				values[Atnum_pids] = palloc(NCHARS * sizeof(char));
				snprintf(values[Atnum_pids], NCHARS, "{%d}",
						 BackendXidGetPid(xmax));
			}

			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);

			/* build a tuple */
			tuple = BuildTupleFromCStrings(attinmeta, values);

			/* make the tuple into a datum */
			result = HeapTupleGetDatum(tuple);

			/*
			 * no need to pfree what we allocated; it's on a short-lived
			 * memory context anyway
			 */

			SRF_RETURN_NEXT(funcctx, result);
		}
		else
		{
			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
		}
	}

	heap_endscan(scan);
	heap_close(mydata->rel, AccessShareLock);

	SRF_RETURN_DONE(funcctx);
}
Ejemplo n.º 5
0
/*
 * Delete error log of the specified relation.  This returns true from master
 * iif all segments and master find the relation.
 */
Datum
gp_truncate_error_log(PG_FUNCTION_ARGS)
{
	text	   *relname;
	char	   *relname_str;
	RangeVar	   *relrv;
	Oid				relid;
	bool		allResults = true;

	relname = PG_GETARG_TEXT_P(0);

	/*
	 * Dispatch the work to segments.
	 */
	if (Gp_role == GP_ROLE_DISPATCH)
	{
		int			i, resultCount = 0;
		StringInfoData	sql, errbuf;
		PGresult  **results;

		initStringInfo(&sql);
		initStringInfo(&errbuf);

		appendStringInfo(&sql,
						 "SELECT pg_catalog.gp_truncate_error_log('%s')",
						 text_to_cstring(relname));

		results = cdbdisp_dispatchRMCommand(sql.data, true, &errbuf,
											&resultCount);

		if (errbuf.len > 0)
			elog(ERROR, "%s", errbuf.data);
		Assert(resultCount > 0);

		for (i = 0; i < resultCount; i++)
		{
			Datum		value;
			bool		isnull;

			if (PQresultStatus(results[i]) != PGRES_TUPLES_OK)
				ereport(ERROR,
						(errmsg("unexpected result from segment: %d",
								PQresultStatus(results[i]))));

			value = ResultToDatum(results[i], 0, 0, boolin, &isnull);
			allResults &= (!isnull && DatumGetBool(value));
			PQclear(results[i]);
		}

		pfree(errbuf.data);
		pfree(sql.data);
	}

	relname_str = text_to_cstring(relname);
	if (strcmp(relname_str, "*.*") == 0)
	{
		/*
		 * Only superuser is allowed to delete log files across database.
		 */
		if (!superuser())
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
					(errmsg("must be superuser to delete all error log files"))));

		ErrorLogDelete(InvalidOid, InvalidOid);
	}
	else if (strcmp(relname_str, "*") == 0)
	{
		/*
		 * Database owner can delete error log files.
		 */
		if (!pg_database_ownercheck(MyDatabaseId, GetUserId()))
			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
						   get_database_name(MyDatabaseId));

		ErrorLogDelete(MyDatabaseId, InvalidOid);
	}
	else
	{
		AclResult	aclresult;

		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
		relid = RangeVarGetRelid(relrv, true);

		/* Return false if the relation does not exist. */
		if (!OidIsValid(relid))
			PG_RETURN_BOOL(false);

		/*
		 * Allow only the table owner to truncate error log.
		 */
		aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, ACL_KIND_CLASS, relrv->relname);

		/* We don't care if this fails or not. */
		ErrorLogDelete(MyDatabaseId, relid);
	}

	/* Return true iif all segments return true. */
	PG_RETURN_BOOL(allResults);
}
Ejemplo n.º 6
0
/*
 * gp_read_error_log
 *
 * Returns set of error log tuples.
 */
Datum
gp_read_error_log(PG_FUNCTION_ARGS)
{
	FuncCallContext	   *funcctx;
	ReadErrorLogContext *context;
	HeapTuple			tuple;
	Datum				result;

	/*
	 * First call setup
	 */
	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext	oldcontext;
		FILE	   *fp;
		text	   *relname;

		funcctx = SRF_FIRSTCALL_INIT();

		relname = PG_GETARG_TEXT_P(0);
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		context = palloc0(sizeof(ReadErrorLogContext));
		funcctx->user_fctx = (void *) context;

		funcctx->tuple_desc = BlessTupleDesc(GetErrorTupleDesc());

		/*
		 * Though this function is usually executed on segment, we dispatch
		 * the execution if it happens to be on QD, and combine the results
		 * into one set.
		 */
		if (Gp_role == GP_ROLE_DISPATCH)
		{
			int		resultCount = 0;
			PGresult **results = NULL;
			StringInfoData sql;
			StringInfoData errbuf;
			int		i;

			initStringInfo(&sql);
			initStringInfo(&errbuf);

			/*
			 * construct SQL
			 */
			appendStringInfo(&sql,
					"SELECT * FROM pg_catalog.gp_read_error_log(%s) ",
							 quote_literal_internal(text_to_cstring(relname)));

			results = cdbdisp_dispatchRMCommand(sql.data, true, &errbuf,
												&resultCount);

			if (errbuf.len > 0)
				elog(ERROR, "%s", errbuf.data);
			Assert(resultCount > 0);

			for (i = 0; i < resultCount; i++)
			{
				if (PQresultStatus(results[i]) != PGRES_TUPLES_OK)
					elog(ERROR, "unexpected result from segment: %d",
								PQresultStatus(results[i]));
				context->numTuples += PQntuples(results[i]);
			}

			pfree(errbuf.data);
			pfree(sql.data);

			context->segResults = results;
			context->numSegResults = resultCount;
		}
		else
		{
			/*
			 * In QE, read the error log.
			 */
			RangeVar	   *relrv;
			Oid				relid;

			relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
			relid = RangeVarGetRelid(relrv, true);

			/*
			 * If the relation has gone, silently return no tuples.
			 */
			if (OidIsValid(relid))
			{
				AclResult aclresult;

				/*
				 * Requires SELECT priv to read error log.
				 */
				aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_SELECT);
				if (aclresult != ACLCHECK_OK)
					aclcheck_error(aclresult, ACL_KIND_CLASS, relrv->relname);

				ErrorLogFileName(context->filename, MyDatabaseId, relid);
				fp = AllocateFile(context->filename, "r");
				context->fp = fp;
			}
		}

		MemoryContextSwitchTo(oldcontext);

		if (Gp_role != GP_ROLE_DISPATCH && !context->fp)
		{
			pfree(context);
			SRF_RETURN_DONE(funcctx);
		}
	}

	funcctx = SRF_PERCALL_SETUP();
	context = (ReadErrorLogContext *) funcctx->user_fctx;

	/*
	 * Read error log, probably on segments.  We don't check Gp_role, however,
	 * in case master also wants to read the file.
	 */
	if (context->fp)
	{
		pg_crc32	crc, written_crc;
		tuple = ErrorLogRead(context->fp, &written_crc);

		/*
		 * CRC check.
		 */
		if (HeapTupleIsValid(tuple))
		{
			INIT_CRC32C(crc);
			COMP_CRC32C(crc, tuple->t_data, tuple->t_len);
			FIN_CRC32C(crc);

			if (!EQ_CRC32C(crc, written_crc))
			{
				elog(LOG, "incorrect checksum in error log %s",
						  context->filename);
				tuple = NULL;
			}
		}

		/*
		 * If we found a valid tuple, return it.  Otherwise, fall through
		 * in the DONE routine.
		 */
		if (HeapTupleIsValid(tuple))
		{
			/*
			 * We need to set typmod for the executor to understand
			 * its type we just blessed.
			 */
			HeapTupleHeaderSetTypMod(tuple->t_data,
									 funcctx->tuple_desc->tdtypmod);

			result = HeapTupleGetDatum(tuple);
			SRF_RETURN_NEXT(funcctx, result);
		}
	}

	/*
	 * If we got results from dispatch, return all the tuples.
	 */
	while (context->currentResult < context->numSegResults)
	{
		Datum		values[NUM_ERRORTABLE_ATTR];
		bool		isnull[NUM_ERRORTABLE_ATTR];
		PGresult   *segres = context->segResults[context->currentResult];
		int			row = context->currentRow;

		if (row >= PQntuples(segres))
		{
			context->currentRow = 0;
			context->currentResult++;
			continue;
		}
		context->currentRow++;

		MemSet(isnull, false, sizeof(isnull));

		values[0] = ResultToDatum(segres, row, 0, timestamptz_in, &isnull[0]);
		values[1] = ResultToDatum(segres, row, 1, textin, &isnull[1]);
		values[2] = ResultToDatum(segres, row, 2, textin, &isnull[2]);
		values[3] = ResultToDatum(segres, row, 3, int4in, &isnull[3]);
		values[4] = ResultToDatum(segres, row, 4, int4in, &isnull[4]);
		values[5] = ResultToDatum(segres, row, 5, textin, &isnull[5]);
		values[6] = ResultToDatum(segres, row, 6, textin, &isnull[6]);
		values[7] = ResultToDatum(segres, row, 7, byteain, &isnull[7]);

		tuple = heap_form_tuple(funcctx->tuple_desc, values, isnull);
		result = HeapTupleGetDatum(tuple);

		SRF_RETURN_NEXT(funcctx, result);
	}

	if (context->segResults != NULL)
	{
		int		i;

		for (i = 0; i < context->numSegResults; i++)
			PQclear(context->segResults[i]);

		/* XXX: better to copy to palloc'ed area */
		free(context->segResults[i]);
	}

	/*
	 * Close the file, if we have opened it.
	 */
	if (context->fp != NULL)
	{
		FreeFile(context->fp);
		context->fp = NULL;
	}

	SRF_RETURN_DONE(funcctx);
}