postgresql/src/include/executor/execPartition.h

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/*--------------------------------------------------------------------
* execPartition.h
* POSTGRES partitioning executor interface
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/include/executor/execPartition.h
*--------------------------------------------------------------------
*/
#ifndef EXECPARTITION_H
#define EXECPARTITION_H
#include "nodes/execnodes.h"
#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
#include "partitioning/partprune.h"
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
/* See execPartition.c for the definitions. */
typedef struct PartitionDispatchData *PartitionDispatch;
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
typedef struct PartitionTupleRouting PartitionTupleRouting;
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
/*
* PartitionRoutingInfo
*
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
* Additional result relation information specific to routing tuples to a
* table partition.
*/
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
typedef struct PartitionRoutingInfo
{
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
/*
* Map for converting tuples in root partitioned table format into
* partition format, or NULL if no conversion is required.
*/
TupleConversionMap *pi_RootToPartitionMap;
/*
* Map for converting tuples in partition format into the root partitioned
* table format, or NULL if no conversion is required.
*/
TupleConversionMap *pi_PartitionToRootMap;
/*
* Slot to store tuples in partition format, or NULL when no translation
* is required between root and partition.
*/
TupleTableSlot *pi_PartitionTupleSlot;
} PartitionRoutingInfo;
/*
* PartitionedRelPruningData - Per-partitioned-table data for run-time pruning
* of partitions. For a multilevel partitioned table, we have one of these
* for the topmost partition plus one for each non-leaf child partition.
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
*
* subplan_map[] and subpart_map[] have the same definitions as in
* PartitionedRelPruneInfo (see plannodes.h); though note that here,
* subpart_map contains indexes into PartitionPruningData.partrelprunedata[].
*
* subplan_map Subplan index by partition index, or -1.
* subpart_map Subpart index by partition index, or -1.
* present_parts A Bitmapset of the partition indexes that we
* have subplans or subparts for.
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
* context Contains the context details required to call
* the partition pruning code.
* pruning_steps List of PartitionPruneSteps used to
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
* perform the actual pruning.
* do_initial_prune true if pruning should be performed during
* executor startup (for this partitioning level).
* do_exec_prune true if pruning should be performed during
* executor run (for this partitioning level).
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
*/
typedef struct PartitionedRelPruningData
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
{
int *subplan_map;
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
int *subpart_map;
Bitmapset *present_parts;
PartitionPruneContext context;
List *pruning_steps;
bool do_initial_prune;
bool do_exec_prune;
} PartitionedRelPruningData;
/*
* PartitionPruningData - Holds all the run-time pruning information for
* a single partitioning hierarchy containing one or more partitions.
* partrelprunedata[] is an array ordered such that parents appear before
* their children; in particular, the first entry is the topmost partition,
* which was actually named in the SQL query.
*/
typedef struct PartitionPruningData
{
int num_partrelprunedata; /* number of array entries */
PartitionedRelPruningData partrelprunedata[FLEXIBLE_ARRAY_MEMBER];
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
} PartitionPruningData;
/*
* PartitionPruneState - State object required for plan nodes to perform
* run-time partition pruning.
*
* This struct can be attached to plan types which support arbitrary Lists of
* subplans containing partitions, to allow subplans to be eliminated due to
* the clauses being unable to match to any tuple that the subplan could
* possibly produce.
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
*
* execparamids Contains paramids of PARAM_EXEC Params found within
* any of the partprunedata structs. Pruning must be
* done again each time the value of one of these
* parameters changes.
* other_subplans Contains indexes of subplans that don't belong to any
* "partprunedata", e.g UNION ALL children that are not
* partitioned tables, or a partitioned table that the
* planner deemed run-time pruning to be useless for.
* These must not be pruned.
* prune_context A short-lived memory context in which to execute the
* partition pruning functions.
* do_initial_prune true if pruning should be performed during executor
* startup (at any hierarchy level).
* do_exec_prune true if pruning should be performed during
* executor run (at any hierarchy level).
* num_partprunedata Number of items in "partprunedata" array.
* partprunedata Array of PartitionPruningData pointers for the plan's
* partitioned relation(s), one for each partitioning
* hierarchy that requires run-time pruning.
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
*/
typedef struct PartitionPruneState
{
Bitmapset *execparamids;
Bitmapset *other_subplans;
MemoryContext prune_context;
bool do_initial_prune;
bool do_exec_prune;
int num_partprunedata;
PartitionPruningData *partprunedata[FLEXIBLE_ARRAY_MEMBER];
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
} PartitionPruneState;
extern PartitionTupleRouting *ExecSetupPartitionTupleRouting(ModifyTableState *mtstate,
Relation rel);
Redesign initialization of partition routing structures This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well as the future MERGE) on partitioned tables. This changes the setup for tuple routing so that it does far less work during the initial setup and pushes more work out to when partitions receive tuples. PartitionDispatchData structs for sub-partitioned tables are only created when a tuple gets routed through it. The possibly large arrays in the PartitionTupleRouting struct have largely been removed. The partitions[] array remains but now never contains any NULL gaps. Previously the NULLs had to be skipped during ExecCleanupTupleRouting(), which could add a large overhead to the cleanup when the number of partitions was large. The partitions[] array is allocated small to start with and only enlarged when we route tuples to enough partitions that it runs out of space. This allows us to keep simple single-row partition INSERTs running quickly. Redesign The arrays in PartitionTupleRouting which stored the tuple translation maps have now been removed. These have been moved out into a PartitionRoutingInfo struct which is an additional field in ResultRelInfo. The find_all_inheritors() call still remains by far the slowest part of ExecSetupPartitionTupleRouting(). This commit just removes the other slow parts. In passing also rename the tuple translation maps from being ParentToChild and ChildToParent to being RootToPartition and PartitionToRoot. The old names mislead you into thinking that a partition of some sub-partitioned table would translate to the rowtype of the sub-partitioned table rather than the root partitioned table. Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera Testing help from Jesper Pedersen and Kato Sho. Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
2018-11-16 18:54:15 +01:00
extern ResultRelInfo *ExecFindPartition(ModifyTableState *mtstate,
ResultRelInfo *rootResultRelInfo,
PartitionTupleRouting *proute,
TupleTableSlot *slot,
EState *estate);
extern void ExecCleanupTupleRouting(ModifyTableState *mtstate,
PartitionTupleRouting *proute);
extern PartitionPruneState *ExecCreatePartitionPruneState(PlanState *planstate,
PartitionPruneInfo *partitionpruneinfo);
Support partition pruning at execution time Existing partition pruning is only able to work at plan time, for query quals that appear in the parsed query. This is good but limiting, as there can be parameters that appear later that can be usefully used to further prune partitions. This commit adds support for pruning subnodes of Append which cannot possibly contain any matching tuples, during execution, by evaluating Params to determine the minimum set of subnodes that can possibly match. We support more than just simple Params in WHERE clauses. Support additionally includes: 1. Parameterized Nested Loop Joins: The parameter from the outer side of the join can be used to determine the minimum set of inner side partitions to scan. 2. Initplans: Once an initplan has been executed we can then determine which partitions match the value from the initplan. Partition pruning is performed in two ways. When Params external to the plan are found to match the partition key we attempt to prune away unneeded Append subplans during the initialization of the executor. This allows us to bypass the initialization of non-matching subplans meaning they won't appear in the EXPLAIN or EXPLAIN ANALYZE output. For parameters whose value is only known during the actual execution then the pruning of these subplans must wait. Subplans which are eliminated during this stage of pruning are still visible in the EXPLAIN output. In order to determine if pruning has actually taken place, the EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never executed due to the elimination of the partition then the execution timing area will state "(never executed)". Whereas, if, for example in the case of parameterized nested loops, the number of loops stated in the EXPLAIN ANALYZE output for certain subplans may appear lower than others due to the subplan having been scanned fewer times. This is due to the list of matching subnodes having to be evaluated whenever a parameter which was found to match the partition key changes. This commit required some additional infrastructure that permits the building of a data structure which is able to perform the translation of the matching partition IDs, as returned by get_matching_partitions, into the list index of a subpaths list, as exist in node types such as Append, MergeAppend and ModifyTable. This allows us to translate a list of clauses into a Bitmapset of all the subpath indexes which must be included to satisfy the clause list. Author: David Rowley, based on an earlier effort by Beena Emerson Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi, Jesper Pedersen Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
2018-04-07 22:54:31 +02:00
extern Bitmapset *ExecFindMatchingSubPlans(PartitionPruneState *prunestate);
extern Bitmapset *ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate,
int nsubplans);
#endif /* EXECPARTITION_H */