database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-27 07:42:10 +03:00
Code Activity

Create an infrastructure for parallel computation in PostgreSQL.

Browse Source 
This does four basic things.  First, it provides convenience routines
to coordinate the startup and shutdown of parallel workers.  Second,
it synchronizes various pieces of state (e.g. GUCs, combo CID
mappings, transaction snapshot) from the parallel group leader to the
worker processes.  Third, it prohibits various operations that would
result in unsafe changes to that state while parallelism is active.
Finally, it propagates events that would result in an ErrorResponse,
NoticeResponse, or NotifyResponse message being sent to the client
from the parallel workers back to the master, from which they can then
be sent on to the client.

Robert Haas, Amit Kapila, Noah Misch, Rushabh Lathia, Jeevan Chalke.
Suggestions and review from Andres Freund, Heikki Linnakangas, Noah
Misch, Simon Riggs, Euler Taveira, and Jim Nasby.
This commit is contained in:
Robert Haas
2015-04-30 15:02:14 -04:00
parent 669c7d20e6
commit 924bcf4f16
37 changed files with 2499 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
src/backend/tcop/utility.c
View File

@@ -128,14 +128,15 @@ CommandIsReadOnly(Node *parsetree)
static void
check_xact_readonly(Node *parsetree)
{
if (!XactReadOnly)
/* Only perform the check if we have a reason to do so. */
if (!XactReadOnly && !IsInParallelMode())
return;
/*
* Note: Commands that need to do more complicated checking are handled
* elsewhere, in particular COPY and plannable statements do their own
* checking. However they should all call PreventCommandIfReadOnly to
* actually throw the error.
* checking. However they should all call PreventCommandIfReadOnly
* or PreventCommandIfParallelMode to actually throw the error.
*/
switch (nodeTag(parsetree))
@@ -208,6 +209,7 @@ check_xact_readonly(Node *parsetree)
case T_ImportForeignSchemaStmt:
case T_SecLabelStmt:
PreventCommandIfReadOnly(CreateCommandTag(parsetree));
PreventCommandIfParallelMode(CreateCommandTag(parsetree));
break;
default:
/* do nothing */
@@ -232,6 +234,24 @@ PreventCommandIfReadOnly(const char *cmdname)
cmdname)));
}
/*
* PreventCommandIfParallelMode: throw error if current (sub)transaction is
* in parallel mode.
*
* This is useful mainly to ensure consistency of the error message wording;
* most callers have checked IsInParallelMode() for themselves.
*/
void
PreventCommandIfParallelMode(const char *cmdname)
{
if (IsInParallelMode())
ereport(ERROR,
(errcode(ERRCODE_INVALID_TRANSACTION_STATE),
/* translator: %s is name of a SQL command, eg CREATE */
errmsg("cannot execute %s during a parallel operation",
cmdname)));
}
/*
* PreventCommandDuringRecovery: throw error if RecoveryInProgress
*
@@ -618,6 +638,7 @@ standard_ProcessUtility(Node *parsetree,
case T_ClusterStmt:
/* we choose to allow this during "read only" transactions */
PreventCommandDuringRecovery("CLUSTER");
/* forbidden in parallel mode due to CommandIsReadOnly */
cluster((ClusterStmt *) parsetree, isTopLevel);
break;
@@ -628,6 +649,7 @@ standard_ProcessUtility(Node *parsetree,
/* we choose to allow this during "read only" transactions */
PreventCommandDuringRecovery((stmt->options & VACOPT_VACUUM) ?
"VACUUM" : "ANALYZE");
/* forbidden in parallel mode due to CommandIsReadOnly */
ExecVacuum(stmt, isTopLevel);
}
break;
@@ -704,6 +726,7 @@ standard_ProcessUtility(Node *parsetree,
* outside a transaction block is presumed to be user error.
*/
RequireTransactionChain(isTopLevel, "LOCK TABLE");
/* forbidden in parallel mode due to CommandIsReadOnly */
LockTableCommand((LockStmt *) parsetree);
break;
@@ -735,6 +758,7 @@ standard_ProcessUtility(Node *parsetree,
/* we choose to allow this during "read only" transactions */
PreventCommandDuringRecovery("REINDEX");
/* forbidden in parallel mode due to CommandIsReadOnly */
switch (stmt->kind)
{
case REINDEX_OBJECT_INDEX: