static int executeXMLPlan(char *szXml)
{
PlannedStmt *pplstmt = COptTasks::PplstmtFromXML(szXml);
// The following steps are required to be able to execute the query.
DestReceiver *pdest = CreateDestReceiver(DestNone, NULL);
QueryDesc *pqueryDesc = CreateQueryDesc(pplstmt, PStrDup("Internal Query") /*plan->query */,
ActiveSnapshot,
InvalidSnapshot,
pdest,
NULL /*paramLI*/,
false);
elog(NOTICE, "Executing thawed plan...");
ExecutorStart(pqueryDesc, 0);
ExecutorRun(pqueryDesc, ForwardScanDirection, 0);
ExecutorEnd(pqueryDesc);
int iProcessed = (int) pqueryDesc->es_processed;
FreeQueryDesc(pqueryDesc);
return iProcessed;
}
static int executeXMLQuery(char *szXml)
{
Query *pquery = COptTasks::PqueryFromXML(szXml);
PlannedStmt *pplstmt = pg_plan_query(pquery, NULL);
DestReceiver *pdest = CreateDestReceiver(DestNone, NULL);
QueryDesc *pqueryDesc = CreateQueryDesc(pplstmt, PStrDup("Internal Query") /*plan->query */,
ActiveSnapshot,
InvalidSnapshot,
pdest,
NULL /*paramLI*/,
false);
elog(NOTICE, "Executing thawed plan...");
ExecutorStart(pqueryDesc, 0);
ExecutorRun(pqueryDesc, ForwardScanDirection, 0);
ExecutorEnd(pqueryDesc);
int iProcessed = (int) pqueryDesc->es_processed;
FreeQueryDesc(pqueryDesc);
return iProcessed;
}
/*
* refresh_matview_datafill
*/
static void
refresh_matview_datafill(DestReceiver *dest, Query *query,
const char *queryString)
{
List *rewritten;
PlannedStmt *plan;
QueryDesc *queryDesc;
Query *copied_query;
/* 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();
}
/*
* PortalCleanup
*
* Clean up a portal when it's dropped. This is the standard cleanup hook
* for portals.
*
* Note: if portal->status is PORTAL_FAILED, we are probably being called
* during error abort, and must be careful to avoid doing anything that
* is likely to fail again.
*/
void
PortalCleanup(Portal portal)
{
QueryDesc *queryDesc;
/*
* sanity checks
*/
AssertArg(PortalIsValid(portal));
AssertArg(portal->cleanup == PortalCleanup);
/*
* Shut down executor, if still running. We skip this during error abort,
* since other mechanisms will take care of releasing executor resources,
* and we can't be sure that ExecutorEnd itself wouldn't fail.
*/
queryDesc = PortalGetQueryDesc(portal);
if (queryDesc)
{
/*
* Reset the queryDesc before anything else. This prevents us from
* trying to shut down the executor twice, in case of an error below.
* The transaction abort mechanisms will take care of resource cleanup
* in such a case.
*/
portal->queryDesc = NULL;
if (portal->status != PORTAL_FAILED)
{
ResourceOwner saveResourceOwner;
/* We must make the portal's resource owner current */
saveResourceOwner = CurrentResourceOwner;
PG_TRY();
{
if (portal->resowner)
CurrentResourceOwner = portal->resowner;
ExecutorFinish(queryDesc);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
}
PG_CATCH();
{
/* Ensure CurrentResourceOwner is restored on error */
CurrentResourceOwner = saveResourceOwner;
PG_RE_THROW();
}
PG_END_TRY();
CurrentResourceOwner = saveResourceOwner;
}
}
}
static int extractFrozenQueryPlanAndExecute(char *pcQuery)
{
Assert(pcQuery);
ULONG ulQueryLen = -1;
memcpy(&ulQueryLen, pcQuery, sizeof(ULONG));
pcQuery+=sizeof(ULONG);
Query *pquery = (Query *) readNodeFromBinaryString(pcQuery, ulQueryLen);
pcQuery+=ulQueryLen;
PlannedStmt *pplstmt = pg_plan_query(pquery, NULL);
if (!pplstmt)
{
elog(ERROR, "Problem with planned statement of query tree %s", gpdb::SzNodeToString(pquery));
}
// The following steps are required to be able to execute the query.
DestReceiver *pdest = CreateDestReceiver(DestNone, NULL);
QueryDesc *pqueryDesc = CreateQueryDesc(pplstmt, PStrDup("Internal Query") /*plan->query */,
ActiveSnapshot,
InvalidSnapshot,
pdest,
NULL /*paramLI*/,
false);
// Do not record gpperfmon information about internal queries
pqueryDesc->gpmon_pkt = NULL;
elog(NOTICE, "Executing thawed plan...");
ExecutorStart(pqueryDesc, 0);
ExecutorRun(pqueryDesc, ForwardScanDirection, 0);
ExecutorEnd(pqueryDesc);
int iProcessed = (int) pqueryDesc->es_processed;
FreeQueryDesc(pqueryDesc);
return iProcessed;
}
/*
* PortalCleanup
*
* Clean up a portal when it's dropped. This is the standard cleanup hook
* for portals.
*/
void
PortalCleanup(Portal portal)
{
QueryDesc *queryDesc;
/*
* sanity checks
*/
AssertArg(PortalIsValid(portal));
AssertArg(portal->cleanup == PortalCleanup);
/*
* Shut down executor, if still running. We skip this during error abort,
* since other mechanisms will take care of releasing executor resources,
* and we can't be sure that ExecutorEnd itself wouldn't fail.
*/
queryDesc = PortalGetQueryDesc(portal);
if (queryDesc)
{
portal->queryDesc = NULL;
if (portal->status != PORTAL_FAILED)
{
ResourceOwner saveResourceOwner;
/* We must make the portal's resource owner current */
saveResourceOwner = CurrentResourceOwner;
PG_TRY();
{
CurrentResourceOwner = portal->resowner;
/* we do not need AfterTriggerEndQuery() here */
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
}
PG_CATCH();
{
/* Ensure CurrentResourceOwner is restored on error */
CurrentResourceOwner = saveResourceOwner;
PG_RE_THROW();
}
PG_END_TRY();
CurrentResourceOwner = saveResourceOwner;
}
}
}
static int extractFrozenPlanAndExecute(char *pcSerializedPS)
{
Assert(pcSerializedPS);
ULONG ulPlannedStmtLen = -1;
memcpy(&ulPlannedStmtLen, pcSerializedPS, sizeof(ULONG));
pcSerializedPS+=sizeof(ULONG);
PlannedStmt *pplstmt = (PlannedStmt *) readNodeFromBinaryString(pcSerializedPS, ulPlannedStmtLen);
pcSerializedPS+=ulPlannedStmtLen;
//The following steps are required to be able to execute the query.
DestReceiver *pdest = CreateDestReceiver(DestNone, NULL);
QueryDesc *pqueryDesc = CreateQueryDesc(pplstmt, PStrDup("Internal Query") /*plan->query */,
ActiveSnapshot,
InvalidSnapshot,
pdest,
NULL /*paramLI*/,
false);
// Do not record gpperfmon information about internal queries
pqueryDesc->gpmon_pkt = NULL;
elog(NOTICE, "Executing thawed plan...");
ExecutorStart(pqueryDesc, 0);
ExecutorRun(pqueryDesc, ForwardScanDirection, 0);
ExecutorEnd(pqueryDesc);
int iProcessed = (int) pqueryDesc->es_processed;
FreeQueryDesc(pqueryDesc);
return iProcessed;
}
/*
* PersistHoldablePortal
*
* Prepare the specified Portal for access outside of the current
* transaction. When this function returns, all future accesses to the
* portal must be done via the Tuplestore (not by invoking the
* executor).
*/
void
PersistHoldablePortal(Portal portal)
{
QueryDesc *queryDesc = PortalGetQueryDesc(portal);
Portal saveActivePortal;
ResourceOwner saveResourceOwner;
MemoryContext savePortalContext;
MemoryContext oldcxt;
/*
* If we're preserving a holdable portal, we had better be inside the
* transaction that originally created it.
*/
Assert(portal->createSubid != InvalidSubTransactionId);
Assert(queryDesc != NULL);
/*
* Caller must have created the tuplestore already.
*/
Assert(portal->holdContext != NULL);
Assert(portal->holdStore != NULL);
/*
* Before closing down the executor, we must copy the tupdesc into
* long-term memory, since it was created in executor memory.
*/
oldcxt = MemoryContextSwitchTo(portal->holdContext);
portal->tupDesc = CreateTupleDescCopy(portal->tupDesc);
MemoryContextSwitchTo(oldcxt);
/*
* Check for improper portal use, and mark portal active.
*/
if (portal->status != PORTAL_READY)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("portal \"%s\" cannot be run", portal->name)));
portal->status = PORTAL_ACTIVE;
/*
* Set up global portal context pointers.
*/
saveActivePortal = ActivePortal;
saveResourceOwner = CurrentResourceOwner;
savePortalContext = PortalContext;
PG_TRY();
{
ActivePortal = portal;
CurrentResourceOwner = portal->resowner;
PortalContext = PortalGetHeapMemory(portal);
MemoryContextSwitchTo(PortalContext);
PushActiveSnapshot(queryDesc->snapshot);
/*
* Rewind the executor: we need to store the entire result set in the
* tuplestore, so that subsequent backward FETCHs can be processed.
*/
ExecutorRewind(queryDesc);
/*
* Change the destination to output to the tuplestore. Note we tell
* the tuplestore receiver to detoast all data passed through it.
*/
queryDesc->dest = CreateDestReceiver(DestTuplestore);
SetTuplestoreDestReceiverParams(queryDesc->dest,
portal->holdStore,
portal->holdContext,
true);
/* Fetch the result set into the tuplestore */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
(*queryDesc->dest->rDestroy) (queryDesc->dest);
queryDesc->dest = NULL;
/*
* Now shut down the inner executor.
*/
portal->queryDesc = NULL; /* prevent double shutdown */
/* we do not need AfterTriggerEndQuery() here */
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
/*
* Set the position in the result set: ideally, this could be
* implemented by just skipping straight to the tuple # that we need
* to be at, but the tuplestore API doesn't support that. So we start
* at the beginning of the tuplestore and iterate through it until we
* reach where we need to be. FIXME someday? (Fortunately, the
* typical case is that we're supposed to be at or near the start of
* the result set, so this isn't as bad as it sounds.)
*/
MemoryContextSwitchTo(portal->holdContext);
if (portal->atEnd)
{
/* we can handle this case even if posOverflow */
while (tuplestore_advance(portal->holdStore, true))
/* continue */ ;
}
else
{
long store_pos;
if (portal->posOverflow) /* oops, cannot trust portalPos */
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not reposition held cursor")));
tuplestore_rescan(portal->holdStore);
for (store_pos = 0; store_pos < portal->portalPos; store_pos++)
{
if (!tuplestore_advance(portal->holdStore, true))
elog(ERROR, "unexpected end of tuple stream");
}
}
}
PG_CATCH();
{
/* Uncaught error while executing portal: mark it dead */
portal->status = PORTAL_FAILED;
/* Restore global vars and propagate error */
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PG_RE_THROW();
}
PG_END_TRY();
MemoryContextSwitchTo(oldcxt);
/* Mark portal not active */
portal->status = PORTAL_READY;
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PopActiveSnapshot();
/*
* We can now release any subsidiary memory of the portal's heap context;
* we'll never use it again. The executor already dropped its context,
* but this will clean up anything that glommed onto the portal's heap via
* PortalContext.
*/
MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
}
/*
* 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);
}
}
/*
* 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;
DestReceiver *dest;
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;
ExecuteQuery(estmt, into, queryString, params, dest, completionTag);
return;
}
Assert(query->commandType == CMD_SELECT);
/*
* 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();
}
/*
* ProcessQuery
* Execute a single plannable query within a PORTAL_MULTI_QUERY,
* PORTAL_ONE_RETURNING, or PORTAL_ONE_MOD_WITH portal
*
* plan: the plan tree for the query
* sourceText: the source text of the query
* params: any parameters needed
* dest: where to send results
* completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
* in which to store a command completion status string.
*
* completionTag may be NULL if caller doesn't want a status string.
*
* Must be called in a memory context that will be reset or deleted on
* error; otherwise the executor's memory usage will be leaked.
*/
static void
ProcessQuery(PlannedStmt *plan,
const char *sourceText,
ParamListInfo params,
DestReceiver *dest,
char *completionTag)
{
QueryDesc *queryDesc;
elog(DEBUG3, "ProcessQuery");
/*
* Create the QueryDesc object
*/
queryDesc = CreateQueryDesc(plan, sourceText,
GetActiveSnapshot(), InvalidSnapshot,
dest, params, 0);
/*
* Call ExecutorStart to prepare the plan for execution
*/
ExecutorStart(queryDesc, 0);
/*
* Run the plan to completion.
*/
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
/*
* Build command completion status string, if caller wants one.
*/
if (completionTag)
{
Oid lastOid;
switch (queryDesc->operation)
{
case CMD_SELECT:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"SELECT %u", queryDesc->estate->es_processed);
break;
case CMD_INSERT:
if (queryDesc->estate->es_processed == 1)
lastOid = queryDesc->estate->es_lastoid;
else
lastOid = InvalidOid;
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"INSERT %u %u", lastOid, queryDesc->estate->es_processed);
break;
case CMD_UPDATE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"UPDATE %u", queryDesc->estate->es_processed);
break;
case CMD_DELETE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"DELETE %u", queryDesc->estate->es_processed);
break;
default:
strcpy(completionTag, "???");
break;
}
}
/*
* Now, we close down all the scans and free allocated resources.
*/
ExecutorFinish(queryDesc);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
}
/*
* 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);
}
/*
* ContinuousQueryWorkerStartup
*
* Launches a CQ worker, which continuously generates partial query results to send
* back to the combiner process.
*/
void
ContinuousQueryWorkerRun(Portal portal, ContinuousViewState *state, QueryDesc *queryDesc, ResourceOwner owner)
{
EState *estate = NULL;
DestReceiver *dest;
CmdType operation;
MemoryContext oldcontext;
int timeoutms = state->maxwaitms;
MemoryContext runcontext;
CQProcEntry *entry = GetCQProcEntry(MyCQId);
ResourceOwner cqowner = ResourceOwnerCreate(NULL, "CQResourceOwner");
bool savereadonly = XactReadOnly;
cq_stat_initialize(state->viewid, MyProcPid);
dest = CreateDestReceiver(DestCombiner);
SetCombinerDestReceiverParams(dest, MyCQId);
/* workers only need read-only transactions */
XactReadOnly = true;
runcontext = AllocSetContextCreate(TopMemoryContext, "CQRunContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
elog(LOG, "\"%s\" worker %d running", queryDesc->plannedstmt->cq_target->relname, MyProcPid);
MarkWorkerAsRunning(MyCQId, MyWorkerId);
pgstat_report_activity(STATE_RUNNING, queryDesc->sourceText);
TupleBufferInitLatch(WorkerTupleBuffer, MyCQId, MyWorkerId, &MyProc->procLatch);
oldcontext = MemoryContextSwitchTo(runcontext);
retry:
PG_TRY();
{
bool xact_commit = true;
TimestampTz last_process = GetCurrentTimestamp();
TimestampTz last_commit = GetCurrentTimestamp();
start_executor(queryDesc, runcontext, cqowner);
CurrentResourceOwner = cqowner;
estate = queryDesc->estate;
operation = queryDesc->operation;
/*
* Initialize context that lives for the duration of a single iteration
* of the main worker loop
*/
CQExecutionContext = AllocSetContextCreate(estate->es_query_cxt, "CQExecutionContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
estate->es_lastoid = InvalidOid;
/*
* Startup combiner receiver
*/
(*dest->rStartup) (dest, operation, queryDesc->tupDesc);
for (;;)
{
if (!TupleBufferHasUnreadSlots())
{
if (TimestampDifferenceExceeds(last_process, GetCurrentTimestamp(), state->emptysleepms))
{
/* force stats flush */
cq_stat_report(true);
pgstat_report_activity(STATE_IDLE, queryDesc->sourceText);
TupleBufferWait(WorkerTupleBuffer, MyCQId, MyWorkerId);
pgstat_report_activity(STATE_RUNNING, queryDesc->sourceText);
}
else
pg_usleep(Min(WAIT_SLEEP_MS, state->emptysleepms) * 1000);
}
TupleBufferResetNotify(WorkerTupleBuffer, MyCQId, MyWorkerId);
if (xact_commit)
StartTransactionCommand();
set_snapshot(estate, cqowner);
CurrentResourceOwner = cqowner;
MemoryContextSwitchTo(estate->es_query_cxt);
estate->es_processed = 0;
estate->es_filtered = 0;
/*
* Run plan on a microbatch
*/
ExecutePlan(estate, queryDesc->planstate, operation,
true, 0, timeoutms, ForwardScanDirection, dest);
IncrementCQExecutions(1);
TupleBufferClearPinnedSlots();
if (state->long_xact)
{
if (TimestampDifferenceExceeds(last_commit, GetCurrentTimestamp(), LONG_RUNNING_XACT_DURATION))
xact_commit = true;
else
xact_commit = false;
}
unset_snapshot(estate, cqowner);
if (xact_commit)
{
CommitTransactionCommand();
last_commit = GetCurrentTimestamp();
}
MemoryContextResetAndDeleteChildren(CQExecutionContext);
MemoryContextSwitchTo(runcontext);
CurrentResourceOwner = cqowner;
if (estate->es_processed || estate->es_filtered)
{
/*
* If the CV query is such that the select does not return any tuples
* ex: select id where id=99; and id=99 does not exist, then this reset
* will fail. What will happen is that the worker will block at the latch for every
* allocated slot, TILL a cv returns a non-zero tuple, at which point
* the worker will resume a simple sleep for the threshold time.
*/
last_process = GetCurrentTimestamp();
/*
* Send stats to the collector
*/
cq_stat_report(false);
}
/* Has the CQ been deactivated? */
if (!entry->active)
{
if (ActiveSnapshotSet())
unset_snapshot(estate, cqowner);
if (IsTransactionState())
CommitTransactionCommand();
break;
}
}
CurrentResourceOwner = cqowner;
/*
* The cleanup functions below expect these things to be registered
*/
RegisterSnapshotOnOwner(estate->es_snapshot, cqowner);
RegisterSnapshotOnOwner(queryDesc->snapshot, cqowner);
RegisterSnapshotOnOwner(queryDesc->crosscheck_snapshot, cqowner);
/* cleanup */
ExecutorFinish(queryDesc);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
}
PG_CATCH();
{
EmitErrorReport();
FlushErrorState();
/* Since the worker is read-only, we can simply commit the transaction. */
if (ActiveSnapshotSet())
unset_snapshot(estate, cqowner);
if (IsTransactionState())
CommitTransactionCommand();
TupleBufferUnpinAllPinnedSlots();
TupleBufferClearReaders();
/* This resets the es_query_ctx and in turn the CQExecutionContext */
MemoryContextResetAndDeleteChildren(runcontext);
IncrementCQErrors(1);
if (continuous_query_crash_recovery)
goto retry;
}
PG_END_TRY();
(*dest->rShutdown) (dest);
MemoryContextSwitchTo(oldcontext);
MemoryContextDelete(runcontext);
XactReadOnly = savereadonly;
/*
* Remove proc-level stats
*/
cq_stat_report(true);
cq_stat_send_purge(state->viewid, MyProcPid, CQ_STAT_WORKER);
CurrentResourceOwner = owner;
}
/*
* PersistHoldablePortal
*
* Prepare the specified Portal for access outside of the current
* transaction. When this function returns, all future accesses to the
* portal must be done via the Tuplestore (not by invoking the
* executor).
*/
void
PersistHoldablePortal(Portal portal)
{
QueryDesc *queryDesc = PortalGetQueryDesc(portal);
Portal saveActivePortal;
ResourceOwner saveResourceOwner;
MemoryContext savePortalContext;
MemoryContext oldcxt;
/*
* If we're preserving a holdable portal, we had better be inside the
* transaction that originally created it.
*/
Assert(portal->createSubid != InvalidSubTransactionId);
Assert(queryDesc != NULL);
/*
* Caller must have created the tuplestore already ... but not a snapshot.
*/
Assert(portal->holdContext != NULL);
Assert(portal->holdStore != NULL);
Assert(portal->holdSnapshot == NULL);
/*
* Before closing down the executor, we must copy the tupdesc into
* long-term memory, since it was created in executor memory.
*/
oldcxt = MemoryContextSwitchTo(portal->holdContext);
portal->tupDesc = CreateTupleDescCopy(portal->tupDesc);
MemoryContextSwitchTo(oldcxt);
/*
* Check for improper portal use, and mark portal active.
*/
MarkPortalActive(portal);
/*
* Set up global portal context pointers.
*/
saveActivePortal = ActivePortal;
saveResourceOwner = CurrentResourceOwner;
savePortalContext = PortalContext;
PG_TRY();
{
ActivePortal = portal;
if (portal->resowner)
CurrentResourceOwner = portal->resowner;
PortalContext = PortalGetHeapMemory(portal);
MemoryContextSwitchTo(PortalContext);
PushActiveSnapshot(queryDesc->snapshot);
/*
* Rewind the executor: we need to store the entire result set in the
* tuplestore, so that subsequent backward FETCHs can be processed.
*/
ExecutorRewind(queryDesc);
/*
* Change the destination to output to the tuplestore. Note we tell
* the tuplestore receiver to detoast all data passed through it; this
* makes it safe to not keep a snapshot associated with the data.
*/
queryDesc->dest = CreateDestReceiver(DestTuplestore);
SetTuplestoreDestReceiverParams(queryDesc->dest,
portal->holdStore,
portal->holdContext,
true);
/* Fetch the result set into the tuplestore */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
(*queryDesc->dest->rDestroy) (queryDesc->dest);
queryDesc->dest = NULL;
/*
* Now shut down the inner executor.
*/
portal->queryDesc = NULL; /* prevent double shutdown */
ExecutorFinish(queryDesc);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
/*
* Set the position in the result set.
*/
MemoryContextSwitchTo(portal->holdContext);
if (portal->atEnd)
{
/*
* Just force the tuplestore forward to its end. The size of the
* skip request here is arbitrary.
*/
while (tuplestore_skiptuples(portal->holdStore, 1000000, true))
/* continue */ ;
}
else
{
tuplestore_rescan(portal->holdStore);
if (!tuplestore_skiptuples(portal->holdStore,
portal->portalPos,
true))
elog(ERROR, "unexpected end of tuple stream");
}
}
PG_CATCH();
{
/* Uncaught error while executing portal: mark it dead */
MarkPortalFailed(portal);
/* Restore global vars and propagate error */
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PG_RE_THROW();
}
PG_END_TRY();
MemoryContextSwitchTo(oldcxt);
/* Mark portal not active */
portal->status = PORTAL_READY;
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PopActiveSnapshot();
/*
* We can now release any subsidiary memory of the portal's heap context;
* we'll never use it again. The executor already dropped its context,
* but this will clean up anything that glommed onto the portal's heap via
* PortalContext.
*/
MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
}
/*
* refresh_matview_datafill
*/
static void
refresh_matview_datafill(DestReceiver *dest, Query *query,
const char *queryString)
{
List *rewritten;
PlannedStmt *plan;
QueryDesc *queryDesc;
List *rtable;
RangeTblEntry *initial_rte;
RangeTblEntry *second_rte;
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 REFRESH MATERIALIZED VIEW");
query = (Query *) linitial(rewritten);
/* Check for user-requested abort. */
CHECK_FOR_INTERRUPTS();
/*
* Kludge here to allow refresh of a materialized view which is invalid
* (that is, it was created or refreshed WITH NO DATA. We flag the first
* two RangeTblEntry list elements, which were added to the front of the
* rewritten Query to keep the rules system happy, with the isResultRel
* flag to indicate that it is OK if they are flagged as invalid. See
* UpdateRangeTableOfViewParse() for details.
*
* NOTE: The rewrite has switched the frist two RTEs, but they are still
* in the first two positions. If that behavior changes, the asserts here
* will fail.
*/
rtable = query->rtable;
initial_rte = ((RangeTblEntry *) linitial(rtable));
Assert(strcmp(initial_rte->alias->aliasname, "new"));
initial_rte->isResultRel = true;
second_rte = ((RangeTblEntry *) lsecond(rtable));
Assert(strcmp(second_rte->alias->aliasname, "old"));
second_rte->isResultRel = true;
/* 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();
}
/*
* ProcessQuery
* Execute a single plannable query within a PORTAL_MULTI_QUERY
* or PORTAL_ONE_RETURNING portal
*
* parsetree: the query tree
* plan: the plan tree for the query
* params: any parameters needed
* dest: where to send results
* completionTag: points to a buffer of size COMPLETION_TAG_BUFSIZE
* in which to store a command completion status string.
*
* completionTag may be NULL if caller doesn't want a status string.
*
* Must be called in a memory context that will be reset or deleted on
* error; otherwise the executor's memory usage will be leaked.
*/
static void
ProcessQuery(Query *parsetree,
Plan *plan,
ParamListInfo params,
DestReceiver *dest,
char *completionTag)
{
int operation = parsetree->commandType;
QueryDesc *queryDesc;
ereport(DEBUG3,
(errmsg_internal("ProcessQuery")));
/*
* Must always set snapshot for plannable queries. Note we assume that
* caller will take care of restoring ActiveSnapshot on exit/error.
*/
ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
/*
* Create the QueryDesc object
*/
queryDesc = CreateQueryDesc(parsetree, plan,
ActiveSnapshot, InvalidSnapshot,
dest, params, false);
/*
* Set up to collect AFTER triggers
*/
AfterTriggerBeginQuery();
/*
* Call ExecutorStart to prepare the plan for execution
*/
ExecutorStart(queryDesc, 0);
/*
* Run the plan to completion.
*/
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
/*
* Build command completion status string, if caller wants one.
*/
if (completionTag)
{
Oid lastOid;
switch (operation)
{
case CMD_SELECT:
strcpy(completionTag, "SELECT");
break;
case CMD_INSERT:
if (queryDesc->estate->es_processed == 1)
lastOid = queryDesc->estate->es_lastoid;
else
lastOid = InvalidOid;
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"INSERT %u %u", lastOid, queryDesc->estate->es_processed);
break;
case CMD_UPDATE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"UPDATE %u", queryDesc->estate->es_processed);
break;
case CMD_DELETE:
snprintf(completionTag, COMPLETION_TAG_BUFSIZE,
"DELETE %u", queryDesc->estate->es_processed);
break;
default:
strcpy(completionTag, "???");
break;
}
}
/* Now take care of any queued AFTER triggers */
AfterTriggerEndQuery(queryDesc->estate);
/*
* Now, we close down all the scans and free allocated resources.
*/
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
FreeSnapshot(ActiveSnapshot);
ActiveSnapshot = NULL;
}
