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postgresql/src/include/executor/execParallel.h

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Parallel executor support. This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
2015-09-29 03:55:57 +02:00
/*--------------------------------------------------------------------
* execParallel.h
* POSTGRES parallel execution interface
*
Update copyright for 2016 Backpatch certain files through 9.1
2016-01-02 19:33:40 +01:00
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
Parallel executor support. This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
2015-09-29 03:55:57 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/include/executor/execParallel.h
*--------------------------------------------------------------------
*/
#ifndef EXECPARALLEL_H
#define EXECPARALLEL_H
#include "access/parallel.h"
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
typedef struct SharedExecutorInstrumentation SharedExecutorInstrumentation;
typedef struct ParallelExecutorInfo
{
pgindent run for 9.6
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PlanState *planstate;
Parallel executor support. This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
2015-09-29 03:55:57 +02:00
ParallelContext *pcxt;
BufferUsage *buffer_usage;
SharedExecutorInstrumentation *instrumentation;
shm_mq_handle **tqueue;
pgindent run for 9.6
2016-06-10 00:02:36 +02:00
bool finished;
} ParallelExecutorInfo;
Parallel executor support. This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
2015-09-29 03:55:57 +02:00
extern ParallelExecutorInfo *ExecInitParallelPlan(PlanState *planstate,
EState *estate, int nworkers);
extern void ExecParallelFinish(ParallelExecutorInfo *pei);
Rewrite interaction of parallel mode with parallel executor support. In the previous coding, before returning from ExecutorRun, we'd shut down all parallel workers. This was dead wrong if ExecutorRun was called with a non-zero tuple count; it had the effect of truncating the query output. To fix, give ExecutePlan control over whether to enter parallel mode, and have it refuse to do so if the tuple count is non-zero. Rewrite the Gather logic so that it can cope with being called outside parallel mode. Commit 7aea8e4f2daa4b39ca9d1309a0c4aadb0f7ed81b is largely to blame for this problem, though this patch modifies some subsequently-committed code which relied on the guarantees it purported to make.
2015-10-16 17:56:02 +02:00
extern void ExecParallelCleanup(ParallelExecutorInfo *pei);
Avoid aggregating worker instrumentation multiple times. Amit Kapila, per design ideas from me.
2015-11-18 18:35:25 +01:00
extern void ExecParallelReinitialize(ParallelExecutorInfo *pei);
Parallel executor support. This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
2015-09-29 03:55:57 +02:00
#endif /* EXECPARALLEL_H */