/*
* 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();
}
