/* * CreateJobSchema creates a job schema with the given schema name. Note that * this function ensures that our pg_ prefixed schema names can be created. * Further note that the created schema does not become visible to other * processes until the transaction commits. */ static void CreateJobSchema(StringInfo schemaName) { const char *queryString = NULL; bool oldAllowSystemTableMods = false; Oid savedUserId = InvalidOid; int savedSecurityContext = 0; /* build a CREATE SCHEMA statement */ CreateSchemaStmt *createSchemaStmt = makeNode(CreateSchemaStmt); createSchemaStmt->schemaname = schemaName->data; createSchemaStmt->authrole = NULL; createSchemaStmt->schemaElts = NIL; /* allow schema names that start with pg_ */ oldAllowSystemTableMods = allowSystemTableMods; allowSystemTableMods = true; /* ensure we're allowed to create this schema */ GetUserIdAndSecContext(&savedUserId, &savedSecurityContext); SetUserIdAndSecContext(CitusExtensionOwner(), SECURITY_LOCAL_USERID_CHANGE); /* actually create schema, and make it visible */ CreateSchemaCommand(createSchemaStmt, queryString); CommandCounterIncrement(); /* and reset environment */ SetUserIdAndSecContext(savedUserId, savedSecurityContext); allowSystemTableMods = oldAllowSystemTableMods; }
/* * GetNextPlacementId allocates and returns a unique placementId for * the placement to be created. This allocation occurs both in shared memory * and in write ahead logs; writing to logs avoids the risk of having shardId * collisions. * * NB: This can be called by any user; for now we have decided that that's * ok. We might want to restrict this to users part of a specific role or such * at some later point. */ uint64 GetNextPlacementId(void) { text *sequenceName = NULL; Oid sequenceId = InvalidOid; Datum sequenceIdDatum = 0; Oid savedUserId = InvalidOid; int savedSecurityContext = 0; Datum placementIdDatum = 0; uint64 placementId = 0; /* * In regression tests, we would like to generate placement IDs consistently * even if the tests run in parallel. Instead of the sequence, we can use * the next_placement_id GUC to specify which shard ID the current session * should generate next. The GUC is automatically increased by 1 every time * a new placement ID is generated. */ if (NextPlacementId > 0) { placementId = NextPlacementId; NextPlacementId += 1; return placementId; } sequenceName = cstring_to_text(PLACEMENTID_SEQUENCE_NAME); sequenceId = ResolveRelationId(sequenceName); sequenceIdDatum = ObjectIdGetDatum(sequenceId); GetUserIdAndSecContext(&savedUserId, &savedSecurityContext); SetUserIdAndSecContext(CitusExtensionOwner(), SECURITY_LOCAL_USERID_CHANGE); /* generate new and unique placement id from sequence */ placementIdDatum = DirectFunctionCall1(nextval_oid, sequenceIdDatum); SetUserIdAndSecContext(savedUserId, savedSecurityContext); placementId = DatumGetInt64(placementIdDatum); return placementId; }
/* * master_get_new_shardid allocates and returns a unique shardId for the shard * to be created. This allocation occurs both in shared memory and in write * ahead logs; writing to logs avoids the risk of having shardId collisions. * * Please note that the caller is still responsible for finalizing shard data * and the shardId with the master node. Further note that this function relies * on an internal sequence created in initdb to generate unique identifiers. * * NB: This can be called by any user; for now we have decided that that's * ok. We might want to restrict this to users part of a specific role or such * at some later point. */ Datum master_get_new_shardid(PG_FUNCTION_ARGS) { text *sequenceName = cstring_to_text(SHARDID_SEQUENCE_NAME); Oid sequenceId = ResolveRelationId(sequenceName); Datum sequenceIdDatum = ObjectIdGetDatum(sequenceId); Oid savedUserId = InvalidOid; int savedSecurityContext = 0; Datum shardIdDatum = 0; GetUserIdAndSecContext(&savedUserId, &savedSecurityContext); SetUserIdAndSecContext(CitusExtensionOwner(), SECURITY_LOCAL_USERID_CHANGE); /* generate new and unique shardId from sequence */ shardIdDatum = DirectFunctionCall1(nextval_oid, sequenceIdDatum); SetUserIdAndSecContext(savedUserId, savedSecurityContext); PG_RETURN_DATUM(shardIdDatum); }
/* * CREATE SCHEMA */ Oid CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString) { const char *schemaName = stmt->schemaname; Oid namespaceId; OverrideSearchPath *overridePath; List *parsetree_list; ListCell *parsetree_item; Oid owner_uid; Oid saved_uid; int save_sec_context; AclResult aclresult; ObjectAddress address; GetUserIdAndSecContext(&saved_uid, &save_sec_context); /* * Who is supposed to own the new schema? */ if (stmt->authrole) owner_uid = get_rolespec_oid(stmt->authrole, false); else owner_uid = saved_uid; /* fill schema name with the user name if not specified */ if (!schemaName) { HeapTuple tuple; tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(owner_uid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for role %u", owner_uid); schemaName = pstrdup(NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname)); ReleaseSysCache(tuple); } /* * To create a schema, must have schema-create privilege on the current * database and must be able to become the target role (this does not * imply that the target role itself must have create-schema privilege). * The latter provision guards against "giveaway" attacks. Note that a * superuser will always have both of these privileges a fortiori. */ aclresult = pg_database_aclcheck(MyDatabaseId, saved_uid, ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_DATABASE, get_database_name(MyDatabaseId)); check_is_member_of_role(saved_uid, owner_uid); /* Additional check to protect reserved schema names */ if (!allowSystemTableMods && IsReservedName(schemaName)) ereport(ERROR, (errcode(ERRCODE_RESERVED_NAME), errmsg("unacceptable schema name \"%s\"", schemaName), errdetail("The prefix \"pg_\" is reserved for system schemas."))); /* * If if_not_exists was given and the schema already exists, bail out. * (Note: we needn't check this when not if_not_exists, because * NamespaceCreate will complain anyway.) We could do this before making * the permissions checks, but since CREATE TABLE IF NOT EXISTS makes its * creation-permission check first, we do likewise. */ if (stmt->if_not_exists && SearchSysCacheExists1(NAMESPACENAME, PointerGetDatum(schemaName))) { ereport(NOTICE, (errcode(ERRCODE_DUPLICATE_SCHEMA), errmsg("schema \"%s\" already exists, skipping", schemaName))); return InvalidOid; } /* * If the requested authorization is different from the current user, * temporarily set the current user so that the object(s) will be created * with the correct ownership. * * (The setting will be restored at the end of this routine, or in case of * error, transaction abort will clean things up.) */ if (saved_uid != owner_uid) SetUserIdAndSecContext(owner_uid, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); /* Create the schema's namespace */ namespaceId = NamespaceCreate(schemaName, owner_uid, false); /* Advance cmd counter to make the namespace visible */ CommandCounterIncrement(); /* * Temporarily make the new namespace be the front of the search path, as * well as the default creation target namespace. This will be undone at * the end of this routine, or upon error. */ overridePath = GetOverrideSearchPath(CurrentMemoryContext); overridePath->schemas = lcons_oid(namespaceId, overridePath->schemas); /* XXX should we clear overridePath->useTemp? */ PushOverrideSearchPath(overridePath); /* * Report the new schema to possibly interested event triggers. Note we * must do this here and not in ProcessUtilitySlow because otherwise the * objects created below are reported before the schema, which would be * wrong. */ ObjectAddressSet(address, NamespaceRelationId, namespaceId); EventTriggerCollectSimpleCommand(address, InvalidObjectAddress, (Node *) stmt); /* * Examine the list of commands embedded in the CREATE SCHEMA command, and * reorganize them into a sequentially executable order with no forward * references. Note that the result is still a list of raw parsetrees --- * we cannot, in general, run parse analysis on one statement until we * have actually executed the prior ones. */ parsetree_list = transformCreateSchemaStmt(stmt); /* * Execute each command contained in the CREATE SCHEMA. Since the grammar * allows only utility commands in CREATE SCHEMA, there is no need to pass * them through parse_analyze() or the rewriter; we can just hand them * straight to ProcessUtility. */ foreach(parsetree_item, parsetree_list) { Node *stmt = (Node *) lfirst(parsetree_item); /* do this step */ ProcessUtility(stmt, queryString, PROCESS_UTILITY_SUBCOMMAND, NULL, None_Receiver, NULL); /* make sure later steps can see the object created here */ CommandCounterIncrement(); }
CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString) #endif { const char *schemaName = stmt->schemaname; const char *authId = stmt->authid; Oid namespaceId; OverrideSearchPath *overridePath; List *parsetree_list; ListCell *parsetree_item; Oid owner_uid; Oid saved_uid; int save_sec_context; AclResult aclresult; GetUserIdAndSecContext(&saved_uid, &save_sec_context); /* * Who is supposed to own the new schema? */ if (authId) owner_uid = get_role_oid(authId, false); else owner_uid = saved_uid; /* * To create a schema, must have schema-create privilege on the current * database and must be able to become the target role (this does not * imply that the target role itself must have create-schema privilege). * The latter provision guards against "giveaway" attacks. Note that a * superuser will always have both of these privileges a fortiori. */ aclresult = pg_database_aclcheck(MyDatabaseId, saved_uid, ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_DATABASE, get_database_name(MyDatabaseId)); check_is_member_of_role(saved_uid, owner_uid); /* Additional check to protect reserved schema names */ if (!allowSystemTableMods && IsReservedName(schemaName)) ereport(ERROR, (errcode(ERRCODE_RESERVED_NAME), errmsg("unacceptable schema name \"%s\"", schemaName), errdetail("The prefix \"pg_\" is reserved for system schemas."))); /* * If the requested authorization is different from the current user, * temporarily set the current user so that the object(s) will be created * with the correct ownership. * * (The setting will be restored at the end of this routine, or in case of * error, transaction abort will clean things up.) */ if (saved_uid != owner_uid) SetUserIdAndSecContext(owner_uid, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); /* Create the schema's namespace */ namespaceId = NamespaceCreate(schemaName, owner_uid, false); /* Advance cmd counter to make the namespace visible */ CommandCounterIncrement(); /* * Temporarily make the new namespace be the front of the search path, as * well as the default creation target namespace. This will be undone at * the end of this routine, or upon error. */ overridePath = GetOverrideSearchPath(CurrentMemoryContext); overridePath->schemas = lcons_oid(namespaceId, overridePath->schemas); /* XXX should we clear overridePath->useTemp? */ PushOverrideSearchPath(overridePath); /* * Examine the list of commands embedded in the CREATE SCHEMA command, and * reorganize them into a sequentially executable order with no forward * references. Note that the result is still a list of raw parsetrees --- * we cannot, in general, run parse analysis on one statement until we * have actually executed the prior ones. */ parsetree_list = transformCreateSchemaStmt(stmt); #ifdef PGXC /* * Add a RemoteQuery node for a query at top level on a remote Coordinator, * if not done already. */ if (!sentToRemote) parsetree_list = AddRemoteQueryNode(parsetree_list, queryString, EXEC_ON_ALL_NODES, false); #endif /* * Execute each command contained in the CREATE SCHEMA. Since the grammar * allows only utility commands in CREATE SCHEMA, there is no need to pass * them through parse_analyze() or the rewriter; we can just hand them * straight to ProcessUtility. */ foreach(parsetree_item, parsetree_list) { Node *stmt = (Node *) lfirst(parsetree_item); /* do this step */ ProcessUtility(stmt, queryString, NULL, false, /* not top level */ None_Receiver, #ifdef PGXC true, #endif /* PGXC */ NULL); /* make sure later steps can see the object created here */ CommandCounterIncrement(); }
/* * CREATE SCHEMA */ void CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString) { const char *schemaName = stmt->schemaname; const char *authId = stmt->authid; Oid namespaceId; OverrideSearchPath *overridePath; List *parsetree_list; ListCell *parsetree_item; Oid owner_uid; Oid saved_uid; int save_sec_context; AclResult aclresult; bool shouldDispatch = (Gp_role == GP_ROLE_DISPATCH && !IsBootstrapProcessingMode()); /* * GPDB: Creation of temporary namespaces is a special case. This statement * is dispatched by the dispatcher node the first time a temporary table is * created. It bypasses all the normal checks and logic of schema creation, * and is routed to the internal routine for creating temporary namespaces, * instead. */ if (stmt->istemp) { Assert(Gp_role == GP_ROLE_EXECUTE); Assert(stmt->schemaname == InvalidOid); Assert(stmt->authid == NULL); Assert(stmt->schemaElts == NIL); Assert(stmt->schemaOid != InvalidOid); Assert(stmt->toastSchemaOid != InvalidOid); InitTempTableNamespaceWithOids(stmt->schemaOid, stmt->toastSchemaOid); return; } GetUserIdAndSecContext(&saved_uid, &save_sec_context); /* * Who is supposed to own the new schema? */ if (authId) owner_uid = get_roleid_checked(authId); else owner_uid = saved_uid; /* * To create a schema, must have schema-create privilege on the current * database and must be able to become the target role (this does not * imply that the target role itself must have create-schema privilege). * The latter provision guards against "giveaway" attacks. Note that a * superuser will always have both of these privileges a fortiori. */ aclresult = pg_database_aclcheck(MyDatabaseId, saved_uid, ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, ACL_KIND_DATABASE, get_database_name(MyDatabaseId)); check_is_member_of_role(saved_uid, owner_uid); /* Additional check to protect reserved schema names */ if (!allowSystemTableModsDDL && IsReservedName(schemaName)) { ereport(ERROR, (errcode(ERRCODE_RESERVED_NAME), errmsg("unacceptable schema name \"%s\"", schemaName), errdetail("The prefix \"%s\" is reserved for system schemas.", GetReservedPrefix(schemaName)))); } /* * If the requested authorization is different from the current user, * temporarily set the current user so that the object(s) will be created * with the correct ownership. * * (The setting will be restored at the end of this routine, or in case * of error, transaction abort will clean things up.) */ if (saved_uid != owner_uid) SetUserIdAndSecContext(owner_uid, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); /* Create the schema's namespace */ if (shouldDispatch || Gp_role != GP_ROLE_EXECUTE) { namespaceId = NamespaceCreate(schemaName, owner_uid, 0); if (shouldDispatch) { elog(DEBUG5, "shouldDispatch = true, namespaceOid = %d", namespaceId); Assert(stmt->schemaOid == 0); stmt->schemaOid = namespaceId; /* * Dispatch the command to all primary and mirror segment dbs. * Starts a global transaction and reconfigures cluster if needed. * Waits for QEs to finish. Exits via ereport(ERROR,...) if error. */ CdbDispatchUtilityStatement((Node *) stmt, DF_CANCEL_ON_ERROR | DF_WITH_SNAPSHOT | DF_NEED_TWO_PHASE, NULL); } /* MPP-6929: metadata tracking */ if (Gp_role == GP_ROLE_DISPATCH) MetaTrackAddObject(NamespaceRelationId, namespaceId, saved_uid, "CREATE", "SCHEMA" ); } else { namespaceId = NamespaceCreate(schemaName, owner_uid, stmt->schemaOid); } /* Advance cmd counter to make the namespace visible */ CommandCounterIncrement(); /* * Temporarily make the new namespace be the front of the search path, as * well as the default creation target namespace. This will be undone at * the end of this routine, or upon error. */ overridePath = GetOverrideSearchPath(CurrentMemoryContext); overridePath->schemas = lcons_oid(namespaceId, overridePath->schemas); /* XXX should we clear overridePath->useTemp? */ PushOverrideSearchPath(overridePath); /* * Examine the list of commands embedded in the CREATE SCHEMA command, and * reorganize them into a sequentially executable order with no forward * references. Note that the result is still a list of raw parsetrees --- * we cannot, in general, run parse analysis on one statement until we * have actually executed the prior ones. */ parsetree_list = transformCreateSchemaStmt(stmt); /* * Execute each command contained in the CREATE SCHEMA. Since the grammar * allows only utility commands in CREATE SCHEMA, there is no need to pass * them through parse_analyze() or the rewriter; we can just hand them * straight to ProcessUtility. */ foreach(parsetree_item, parsetree_list) { Node *stmt = (Node *) lfirst(parsetree_item); /* do this step */ ProcessUtility(stmt, queryString, NULL, false, /* not top level */ None_Receiver, NULL); /* make sure later steps can see the object created here */ CommandCounterIncrement(); }
/* * ExecCreateTableAs -- execute a CREATE TABLE AS command */ void ExecCreateTableAs(CreateTableAsStmt *stmt, const char *queryString, ParamListInfo params, char *completionTag) { Query *query = (Query *) stmt->query; IntoClause *into = stmt->into; bool is_matview = (into->viewQuery != NULL); DestReceiver *dest; Oid save_userid = InvalidOid; int save_sec_context = 0; int save_nestlevel = 0; List *rewritten; PlannedStmt *plan; QueryDesc *queryDesc; ScanDirection dir; /* * Create the tuple receiver object and insert info it will need */ dest = CreateIntoRelDestReceiver(into); /* * The contained Query could be a SELECT, or an EXECUTE utility command. * If the latter, we just pass it off to ExecuteQuery. */ Assert(IsA(query, Query)); if (query->commandType == CMD_UTILITY && IsA(query->utilityStmt, ExecuteStmt)) { ExecuteStmt *estmt = (ExecuteStmt *) query->utilityStmt; Assert(!is_matview); /* excluded by syntax */ ExecuteQuery(estmt, into, queryString, params, dest, completionTag); return; } Assert(query->commandType == CMD_SELECT); /* * For materialized views, lock down security-restricted operations and * arrange to make GUC variable changes local to this command. This is * not necessary for security, but this keeps the behavior similar to * REFRESH MATERIALIZED VIEW. Otherwise, one could create a materialized * view not possible to refresh. */ if (is_matview) { GetUserIdAndSecContext(&save_userid, &save_sec_context); SetUserIdAndSecContext(save_userid, save_sec_context | SECURITY_RESTRICTED_OPERATION); save_nestlevel = NewGUCNestLevel(); } /* * Parse analysis was done already, but we still have to run the rule * rewriter. We do not do AcquireRewriteLocks: we assume the query either * came straight from the parser, or suitable locks were acquired by * plancache.c. * * Because the rewriter and planner tend to scribble on the input, we make * a preliminary copy of the source querytree. This prevents problems in * the case that CTAS is in a portal or plpgsql function and is executed * repeatedly. (See also the same hack in EXPLAIN and PREPARE.) */ rewritten = QueryRewrite((Query *) copyObject(query)); /* SELECT should never rewrite to more or less than one SELECT query */ if (list_length(rewritten) != 1) elog(ERROR, "unexpected rewrite result for CREATE TABLE AS SELECT"); query = (Query *) linitial(rewritten); Assert(query->commandType == CMD_SELECT); /* plan the query */ plan = pg_plan_query(query, 0, params); /* * Use a snapshot with an updated command ID to ensure this query sees * results of any previously executed queries. (This could only matter if * the planner executed an allegedly-stable function that changed the * database contents, but let's do it anyway to be parallel to the EXPLAIN * code path.) */ PushCopiedSnapshot(GetActiveSnapshot()); UpdateActiveSnapshotCommandId(); /* Create a QueryDesc, redirecting output to our tuple receiver */ queryDesc = CreateQueryDesc(plan, queryString, GetActiveSnapshot(), InvalidSnapshot, dest, params, 0); /* call ExecutorStart to prepare the plan for execution */ ExecutorStart(queryDesc, GetIntoRelEFlags(into)); /* * Normally, we run the plan to completion; but if skipData is specified, * just do tuple receiver startup and shutdown. */ if (into->skipData) dir = NoMovementScanDirection; else dir = ForwardScanDirection; /* run the plan */ ExecutorRun(queryDesc, dir, 0L); /* save the rowcount if we're given a completionTag to fill */ if (completionTag) snprintf(completionTag, COMPLETION_TAG_BUFSIZE, "SELECT %u", queryDesc->estate->es_processed); /* and clean up */ ExecutorFinish(queryDesc); ExecutorEnd(queryDesc); FreeQueryDesc(queryDesc); PopActiveSnapshot(); if (is_matview) { /* Roll back any GUC changes */ AtEOXact_GUC(false, save_nestlevel); /* Restore userid and security context */ SetUserIdAndSecContext(save_userid, save_sec_context); } }
/* * refresh_by_match_merge * * Refresh a materialized view with transactional semantics, while allowing * concurrent reads. * * This is called after a new version of the data has been created in a * temporary table. It performs a full outer join against the old version of * the data, producing "diff" results. This join cannot work if there are any * duplicated rows in either the old or new versions, in the sense that every * column would compare as equal between the two rows. It does work correctly * in the face of rows which have at least one NULL value, with all non-NULL * columns equal. The behavior of NULLs on equality tests and on UNIQUE * indexes turns out to be quite convenient here; the tests we need to make * are consistent with default behavior. If there is at least one UNIQUE * index on the materialized view, we have exactly the guarantee we need. * * The temporary table used to hold the diff results contains just the TID of * the old record (if matched) and the ROW from the new table as a single * column of complex record type (if matched). * * Once we have the diff table, we perform set-based DELETE and INSERT * operations against the materialized view, and discard both temporary * tables. * * Everything from the generation of the new data to applying the differences * takes place under cover of an ExclusiveLock, since it seems as though we * would want to prohibit not only concurrent REFRESH operations, but also * incremental maintenance. It also doesn't seem reasonable or safe to allow * SELECT FOR UPDATE or SELECT FOR SHARE on rows being updated or deleted by * this command. */ static void refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner, int save_sec_context) { StringInfoData querybuf; Relation matviewRel; Relation tempRel; char *matviewname; char *tempname; char *diffname; TupleDesc tupdesc; bool foundUniqueIndex; List *indexoidlist; ListCell *indexoidscan; int16 relnatts; bool *usedForQual; initStringInfo(&querybuf); matviewRel = heap_open(matviewOid, NoLock); matviewname = quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)), RelationGetRelationName(matviewRel)); tempRel = heap_open(tempOid, NoLock); tempname = quote_qualified_identifier(get_namespace_name(RelationGetNamespace(tempRel)), RelationGetRelationName(tempRel)); diffname = make_temptable_name_n(tempname, 2); relnatts = matviewRel->rd_rel->relnatts; usedForQual = (bool *) palloc0(sizeof(bool) * relnatts); /* Open SPI context. */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "SPI_connect failed"); /* Analyze the temp table with the new contents. */ appendStringInfo(&querybuf, "ANALYZE %s", tempname); if (SPI_exec(querybuf.data, 0) != SPI_OK_UTILITY) elog(ERROR, "SPI_exec failed: %s", querybuf.data); /* * We need to ensure that there are not duplicate rows without NULLs in * the new data set before we can count on the "diff" results. Check for * that in a way that allows showing the first duplicated row found. Even * after we pass this test, a unique index on the materialized view may * find a duplicate key problem. */ resetStringInfo(&querybuf); appendStringInfo(&querybuf, "SELECT newdata FROM %s newdata " "WHERE newdata IS NOT NULL AND EXISTS " "(SELECT * FROM %s newdata2 WHERE newdata2 IS NOT NULL " "AND newdata2 OPERATOR(pg_catalog.*=) newdata " "AND newdata2.ctid OPERATOR(pg_catalog.<>) " "newdata.ctid) LIMIT 1", tempname, tempname); if (SPI_execute(querybuf.data, false, 1) != SPI_OK_SELECT) elog(ERROR, "SPI_exec failed: %s", querybuf.data); if (SPI_processed > 0) { ereport(ERROR, (errcode(ERRCODE_CARDINALITY_VIOLATION), errmsg("new data for \"%s\" contains duplicate rows without any null columns", RelationGetRelationName(matviewRel)), errdetail("Row: %s", SPI_getvalue(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1)))); } SetUserIdAndSecContext(relowner, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); /* Start building the query for creating the diff table. */ resetStringInfo(&querybuf); appendStringInfo(&querybuf, "CREATE TEMP TABLE %s AS " "SELECT mv.ctid AS tid, newdata " "FROM %s mv FULL JOIN %s newdata ON (", diffname, matviewname, tempname); /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache. We will test for equality on all * columns present in all unique indexes which only reference columns and * include all rows. */ tupdesc = matviewRel->rd_att; foundUniqueIndex = false; indexoidlist = RelationGetIndexList(matviewRel); foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); Relation indexRel; Form_pg_index indexStruct; indexRel = index_open(indexoid, RowExclusiveLock); indexStruct = indexRel->rd_index; /* * We're only interested if it is unique, valid, contains no * expressions, and is not partial. */ if (indexStruct->indisunique && IndexIsValid(indexStruct) && RelationGetIndexExpressions(indexRel) == NIL && RelationGetIndexPredicate(indexRel) == NIL) { int numatts = indexStruct->indnatts; int i; /* Add quals for all columns from this index. */ for (i = 0; i < numatts; i++) { int attnum = indexStruct->indkey.values[i]; Oid type; Oid op; const char *colname; /* * Only include the column once regardless of how many times * it shows up in how many indexes. */ if (usedForQual[attnum - 1]) continue; usedForQual[attnum - 1] = true; /* * Actually add the qual, ANDed with any others. */ if (foundUniqueIndex) appendStringInfoString(&querybuf, " AND "); colname = quote_identifier(NameStr((tupdesc->attrs[attnum - 1])->attname)); appendStringInfo(&querybuf, "newdata.%s ", colname); type = attnumTypeId(matviewRel, attnum); op = lookup_type_cache(type, TYPECACHE_EQ_OPR)->eq_opr; mv_GenerateOper(&querybuf, op); appendStringInfo(&querybuf, " mv.%s", colname); foundUniqueIndex = true; } } /* Keep the locks, since we're about to run DML which needs them. */ index_close(indexRel, NoLock); }
/* * ExecRefreshMatView -- execute a REFRESH MATERIALIZED VIEW command * * This refreshes the materialized view by creating a new table and swapping * the relfilenodes of the new table and the old materialized view, so the OID * of the original materialized view is preserved. Thus we do not lose GRANT * nor references to this materialized view. * * If WITH NO DATA was specified, this is effectively like a TRUNCATE; * otherwise it is like a TRUNCATE followed by an INSERT using the SELECT * statement associated with the materialized view. The statement node's * skipData field shows whether the clause was used. * * Indexes are rebuilt too, via REINDEX. Since we are effectively bulk-loading * the new heap, it's better to create the indexes afterwards than to fill them * incrementally while we load. * * The matview's "populated" state is changed based on whether the contents * reflect the result set of the materialized view's query. */ void ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString, ParamListInfo params, char *completionTag) { Oid matviewOid; Relation matviewRel; RewriteRule *rule; List *actions; Query *dataQuery; Oid tableSpace; Oid relowner; Oid OIDNewHeap; DestReceiver *dest; bool concurrent; LOCKMODE lockmode; Oid save_userid; int save_sec_context; int save_nestlevel; /* Determine strength of lock needed. */ concurrent = stmt->concurrent; lockmode = concurrent ? ExclusiveLock : AccessExclusiveLock; /* * Get a lock until end of transaction. */ matviewOid = RangeVarGetRelidExtended(stmt->relation, lockmode, false, false, RangeVarCallbackOwnsTable, NULL); matviewRel = heap_open(matviewOid, NoLock); /* Make sure it is a materialized view. */ if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("\"%s\" is not a materialized view", RelationGetRelationName(matviewRel)))); /* Check that CONCURRENTLY is not specified if not populated. */ if (concurrent && !RelationIsPopulated(matviewRel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("CONCURRENTLY cannot be used when the materialized view is not populated"))); /* Check that conflicting options have not been specified. */ if (concurrent && stmt->skipData) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("CONCURRENTLY and WITH NO DATA options cannot be used together"))); /* We don't allow an oid column for a materialized view. */ Assert(!matviewRel->rd_rel->relhasoids); /* * Check that everything is correct for a refresh. Problems at this point * are internal errors, so elog is sufficient. */ if (matviewRel->rd_rel->relhasrules == false || matviewRel->rd_rules->numLocks < 1) elog(ERROR, "materialized view \"%s\" is missing rewrite information", RelationGetRelationName(matviewRel)); if (matviewRel->rd_rules->numLocks > 1) elog(ERROR, "materialized view \"%s\" has too many rules", RelationGetRelationName(matviewRel)); rule = matviewRel->rd_rules->rules[0]; if (rule->event != CMD_SELECT || !(rule->isInstead)) elog(ERROR, "the rule for materialized view \"%s\" is not a SELECT INSTEAD OF rule", RelationGetRelationName(matviewRel)); actions = rule->actions; if (list_length(actions) != 1) elog(ERROR, "the rule for materialized view \"%s\" is not a single action", RelationGetRelationName(matviewRel)); /* * The stored query was rewritten at the time of the MV definition, but * has not been scribbled on by the planner. */ dataQuery = (Query *) linitial(actions); Assert(IsA(dataQuery, Query)); /* * Check for active uses of the relation in the current transaction, such * as open scans. * * NB: We count on this to protect us against problems with refreshing the * data using HEAP_INSERT_FROZEN. */ CheckTableNotInUse(matviewRel, "REFRESH MATERIALIZED VIEW"); /* * Tentatively mark the matview as populated or not (this will roll back * if we fail later). */ SetMatViewPopulatedState(matviewRel, !stmt->skipData); relowner = matviewRel->rd_rel->relowner; /* * Switch to the owner's userid, so that any functions are run as that * user. Also arrange to make GUC variable changes local to this command. * Don't lock it down too tight to create a temporary table just yet. We * will switch modes when we are about to execute user code. */ GetUserIdAndSecContext(&save_userid, &save_sec_context); SetUserIdAndSecContext(relowner, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); save_nestlevel = NewGUCNestLevel(); /* Concurrent refresh builds new data in temp tablespace, and does diff. */ if (concurrent) tableSpace = GetDefaultTablespace(RELPERSISTENCE_TEMP); else tableSpace = matviewRel->rd_rel->reltablespace; /* * Create the transient table that will receive the regenerated data. Lock * it against access by any other process until commit (by which time it * will be gone). */ OIDNewHeap = make_new_heap(matviewOid, tableSpace, concurrent, ExclusiveLock); LockRelationOid(OIDNewHeap, AccessExclusiveLock); dest = CreateTransientRelDestReceiver(OIDNewHeap); /* * Now lock down security-restricted operations. */ SetUserIdAndSecContext(relowner, save_sec_context | SECURITY_RESTRICTED_OPERATION); /* Generate the data, if wanted. */ if (!stmt->skipData) refresh_matview_datafill(dest, dataQuery, queryString); heap_close(matviewRel, NoLock); /* Make the matview match the newly generated data. */ if (concurrent) { int old_depth = matview_maintenance_depth; PG_TRY(); { refresh_by_match_merge(matviewOid, OIDNewHeap, relowner, save_sec_context); } PG_CATCH(); { matview_maintenance_depth = old_depth; PG_RE_THROW(); } PG_END_TRY(); Assert(matview_maintenance_depth == old_depth); } else refresh_by_heap_swap(matviewOid, OIDNewHeap); /* Roll back any GUC changes */ AtEOXact_GUC(false, save_nestlevel); /* Restore userid and security context */ SetUserIdAndSecContext(save_userid, save_sec_context); }
/* * refresh_matview_datafill */ static void refresh_matview_datafill(DestReceiver *dest, Query *query, const char *queryString, Oid relowner) { List *rewritten; PlannedStmt *plan; QueryDesc *queryDesc; Oid save_userid; int save_sec_context; int save_nestlevel; Query *copied_query; /* * Switch to the owner's userid, so that any functions are run as that * user. Also lock down security-restricted operations and arrange to * make GUC variable changes local to this command. */ GetUserIdAndSecContext(&save_userid, &save_sec_context); SetUserIdAndSecContext(relowner, save_sec_context | SECURITY_RESTRICTED_OPERATION); save_nestlevel = NewGUCNestLevel(); /* Lock and rewrite, using a copy to preserve the original query. */ copied_query = copyObject(query); AcquireRewriteLocks(copied_query, true, false); rewritten = QueryRewrite(copied_query); /* SELECT should never rewrite to more or less than one SELECT query */ if (list_length(rewritten) != 1) elog(ERROR, "unexpected rewrite result for REFRESH MATERIALIZED VIEW"); query = (Query *) linitial(rewritten); /* Check for user-requested abort. */ CHECK_FOR_INTERRUPTS(); /* Plan the query which will generate data for the refresh. */ plan = pg_plan_query(query, 0, NULL); /* * Use a snapshot with an updated command ID to ensure this query sees * results of any previously executed queries. (This could only matter if * the planner executed an allegedly-stable function that changed the * database contents, but let's do it anyway to be safe.) */ PushCopiedSnapshot(GetActiveSnapshot()); UpdateActiveSnapshotCommandId(); /* Create a QueryDesc, redirecting output to our tuple receiver */ queryDesc = CreateQueryDesc(plan, queryString, GetActiveSnapshot(), InvalidSnapshot, dest, NULL, 0); /* call ExecutorStart to prepare the plan for execution */ ExecutorStart(queryDesc, EXEC_FLAG_WITHOUT_OIDS); /* run the plan */ ExecutorRun(queryDesc, ForwardScanDirection, 0L); /* and clean up */ ExecutorFinish(queryDesc); ExecutorEnd(queryDesc); FreeQueryDesc(queryDesc); PopActiveSnapshot(); /* Roll back any GUC changes */ AtEOXact_GUC(false, save_nestlevel); /* Restore userid and security context */ SetUserIdAndSecContext(save_userid, save_sec_context); }
/* * FetchRegularTable fetches the given table's data using the copy out command. * The function then fetches the DDL commands necessary to create this table's * replica, and locally applies these DDL commands. Last, the function copies * the fetched table data into the created table; and on success, returns true. * On failure due to connectivity issues with remote node, the function returns * false. On other types of failures, the function errors out. */ static bool FetchRegularTable(const char *nodeName, uint32 nodePort, const char *tableName) { StringInfo localFilePath = NULL; StringInfo remoteCopyCommand = NULL; List *ddlCommandList = NIL; ListCell *ddlCommandCell = NULL; CopyStmt *localCopyCommand = NULL; RangeVar *localTable = NULL; uint64 shardId = 0; bool received = false; StringInfo queryString = NULL; const char *tableOwner = NULL; Oid tableOwnerId = InvalidOid; Oid savedUserId = InvalidOid; int savedSecurityContext = 0; List *tableNameList = NIL; /* copy remote table's data to this node in an idempotent manner */ shardId = ExtractShardId(tableName); localFilePath = makeStringInfo(); appendStringInfo(localFilePath, "base/%s/%s" UINT64_FORMAT, PG_JOB_CACHE_DIR, TABLE_FILE_PREFIX, shardId); remoteCopyCommand = makeStringInfo(); appendStringInfo(remoteCopyCommand, COPY_OUT_COMMAND, tableName); received = ReceiveRegularFile(nodeName, nodePort, remoteCopyCommand, localFilePath); if (!received) { return false; } /* fetch the ddl commands needed to create the table */ tableOwner = RemoteTableOwner(nodeName, nodePort, tableName); if (tableOwner == NULL) { return false; } tableOwnerId = get_role_oid(tableOwner, false); /* fetch the ddl commands needed to create the table */ ddlCommandList = TableDDLCommandList(nodeName, nodePort, tableName); if (ddlCommandList == NIL) { return false; } /* * Apply DDL commands against the database. Note that on failure from here * on, we immediately error out instead of returning false. Have to do * this as the table's owner to ensure the local table is created with * compatible permissions. */ GetUserIdAndSecContext(&savedUserId, &savedSecurityContext); SetUserIdAndSecContext(tableOwnerId, SECURITY_LOCAL_USERID_CHANGE); foreach(ddlCommandCell, ddlCommandList) { StringInfo ddlCommand = (StringInfo) lfirst(ddlCommandCell); Node *ddlCommandNode = ParseTreeNode(ddlCommand->data); ProcessUtility(ddlCommandNode, ddlCommand->data, PROCESS_UTILITY_TOPLEVEL, NULL, None_Receiver, NULL); CommandCounterIncrement(); }