partdesc.h

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/*-------------------------------------------------------------------------
 *
 * partdesc.h
 *
 * Copyright (c) 1996-2025, PostgreSQL Global Development Group
 *
 * src/include/partitioning/partdesc.h
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef PARTDESC_H
#define PARTDESC_H
 
#include "partitioning/partdefs.h"
#include "utils/relcache.h"
 
/*
 * Information about partitions of a partitioned table.
 *
 * For partitioned tables where detached partitions exist, we only cache
 * descriptors that include all partitions, including detached; when we're
 * requested a descriptor without the detached partitions, we create one
 * afresh each time.  (The reason for this is that the set of detached
 * partitions that are visible to each caller depends on the snapshot it has,
 * so it's pretty much impossible to evict a descriptor from cache at the
 * right time.)
 */
typedef struct PartitionDescData
{
    int         nparts;         /* Number of partitions */
    bool        detached_exist; /* Are there any detached partitions? */
    Oid        *oids;           /* Array of 'nparts' elements containing
                                 * partition OIDs in order of their bounds */
    bool       *is_leaf;        /* Array of 'nparts' elements storing whether
                                 * the corresponding 'oids' element belongs to
                                 * a leaf partition or not */
    PartitionBoundInfo boundinfo;   /* collection of partition bounds */
 
    /* Caching fields to cache lookups in get_partition_for_tuple() */
 
    /*
     * Index into the PartitionBoundInfo's datum array for the last found
     * partition or -1 if none.
     */
    int         last_found_datum_index;
 
    /*
     * Partition index of the last found partition or -1 if none has been
     * found yet.
     */
    int         last_found_part_index;
 
    /*
     * For LIST partitioning, this is the number of times in a row that the
     * datum we're looking for a partition for matches the datum in the
     * last_found_datum_index index of the boundinfo->datums array.  For RANGE
     * partitioning, this is the number of times in a row we've found that the
     * datum we're looking for a partition for falls into the range of the
     * partition corresponding to the last_found_datum_index index of the
     * boundinfo->datums array.
     */
    int         last_found_count;
} PartitionDescData;
 
 
extern PartitionDesc RelationGetPartitionDesc(Relation rel, bool omit_detached);
 
extern PartitionDirectory CreatePartitionDirectory(MemoryContext mcxt, bool omit_detached);
extern PartitionDesc PartitionDirectoryLookup(PartitionDirectory, Relation);
extern void DestroyPartitionDirectory(PartitionDirectory pdir);
 
extern Oid  get_default_oid_from_partdesc(PartitionDesc partdesc);
 
#endif                          /* PARTCACHE_H */