partprune.h

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/*-------------------------------------------------------------------------
 *
 * partprune.h
 *    prototypes for partprune.c
 *
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/partitioning/partprune.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PARTPRUNE_H
#define PARTPRUNE_H
 
#include "nodes/execnodes.h"
#include "partitioning/partdefs.h"
 
struct PlannerInfo;             /* avoid including pathnodes.h here */
struct RelOptInfo;
 
 
/*
 * PartitionPruneContext
 *      Stores information needed at runtime for pruning computations
 *      related to a single partitioned table.
 *
 * strategy         Partition strategy, e.g. LIST, RANGE, HASH.
 * partnatts        Number of columns in the partition key.
 * nparts           Number of partitions in this partitioned table.
 * boundinfo        Partition boundary info for the partitioned table.
 * partcollation    Array of partnatts elements, storing the collations of the
 *                  partition key columns.
 * partsupfunc      Array of FmgrInfos for the comparison or hashing functions
 *                  associated with the partition keys (partnatts elements).
 *                  (This points into the partrel's partition key, typically.)
 * stepcmpfuncs     Array of FmgrInfos for the comparison or hashing function
 *                  for each pruning step and partition key.
 * ppccontext       Memory context holding this PartitionPruneContext's
 *                  subsidiary data, such as the FmgrInfos.
 * planstate        Points to the parent plan node's PlanState when called
 *                  during execution; NULL when called from the planner.
 * exprcontext      ExprContext to use when evaluating pruning expressions
 * exprstates       Array of ExprStates, indexed as per PruneCxtStateIdx; one
 *                  for each partition key in each pruning step.  Allocated if
 *                  planstate is non-NULL, otherwise NULL.
 */
typedef struct PartitionPruneContext
{
    char        strategy;
    int         partnatts;
    int         nparts;
    PartitionBoundInfo boundinfo;
    Oid        *partcollation;
    FmgrInfo   *partsupfunc;
    FmgrInfo   *stepcmpfuncs;
    MemoryContext ppccontext;
    PlanState  *planstate;
    ExprContext *exprcontext;
    ExprState **exprstates;
} PartitionPruneContext;
 
/*
 * PruneCxtStateIdx() computes the correct index into the stepcmpfuncs[]
 * and exprstates[] arrays for step step_id and partition key column keyno.
 * (Note: there is code that assumes the entries for a given step are
 * sequential, so this is not chosen freely.)
 */
#define PruneCxtStateIdx(partnatts, step_id, keyno) \
    ((partnatts) * (step_id) + (keyno))
 
extern PartitionPruneInfo *make_partition_pruneinfo(struct PlannerInfo *root,
                                                    struct RelOptInfo *parentrel,
                                                    List *subpaths,
                                                    List *prunequal);
extern Bitmapset *prune_append_rel_partitions(struct RelOptInfo *rel);
extern Bitmapset *get_matching_partitions(PartitionPruneContext *context,
                                          List *pruning_steps);
 
#endif                          /* PARTPRUNE_H */