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e2fa76d80b
This patch fixes the planner so that it can generate nestloop-with- inner-indexscan plans even with one or more levels of joining between the indexscan and the nestloop join that is supplying the parameter. The executor was fixed to handle such cases some time ago, but the planner was not ready. This should improve our plans in many situations where join ordering restrictions formerly forced complete table scans. There is probably a fair amount of tuning work yet to be done, because of various heuristics that have been added to limit the number of parameterized paths considered. However, we are not going to find out what needs to be adjusted until the code gets some real-world use, so it's time to get it in there where it can be tested easily. Note API change for index AM amcostestimate functions. I'm not aware of any non-core index AMs, but if there are any, they will need minor adjustments.
97 lines
3.4 KiB
C
97 lines
3.4 KiB
C
/*-------------------------------------------------------------------------
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*
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* bitmapset.h
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* PostgreSQL generic bitmap set package
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*
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* A bitmap set can represent any set of nonnegative integers, although
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* it is mainly intended for sets where the maximum value is not large,
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* say at most a few hundred. By convention, a NULL pointer is always
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* accepted by all operations to represent the empty set. (But beware
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* that this is not the only representation of the empty set. Use
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* bms_is_empty() in preference to testing for NULL.)
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*
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*
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* Copyright (c) 2003-2012, PostgreSQL Global Development Group
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*
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* src/include/nodes/bitmapset.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef BITMAPSET_H
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#define BITMAPSET_H
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/*
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* Data representation
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*/
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/* The unit size can be adjusted by changing these three declarations: */
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#define BITS_PER_BITMAPWORD 32
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typedef uint32 bitmapword; /* must be an unsigned type */
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typedef int32 signedbitmapword; /* must be the matching signed type */
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typedef struct Bitmapset
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{
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int nwords; /* number of words in array */
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bitmapword words[1]; /* really [nwords] */
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} Bitmapset; /* VARIABLE LENGTH STRUCT */
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/* result of bms_subset_compare */
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typedef enum
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{
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BMS_EQUAL, /* sets are equal */
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BMS_SUBSET1, /* first set is a subset of the second */
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BMS_SUBSET2, /* second set is a subset of the first */
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BMS_DIFFERENT /* neither set is a subset of the other */
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} BMS_Comparison;
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/* result of bms_membership */
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typedef enum
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{
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BMS_EMPTY_SET, /* 0 members */
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BMS_SINGLETON, /* 1 member */
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BMS_MULTIPLE /* >1 member */
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} BMS_Membership;
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/*
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* function prototypes in nodes/bitmapset.c
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*/
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extern Bitmapset *bms_copy(const Bitmapset *a);
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extern bool bms_equal(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_make_singleton(int x);
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extern void bms_free(Bitmapset *a);
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extern Bitmapset *bms_union(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_intersect(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_difference(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_is_subset(const Bitmapset *a, const Bitmapset *b);
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extern BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_is_member(int x, const Bitmapset *a);
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extern bool bms_overlap(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b);
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extern int bms_singleton_member(const Bitmapset *a);
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extern int bms_num_members(const Bitmapset *a);
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/* optimized tests when we don't need to know exact membership count: */
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extern BMS_Membership bms_membership(const Bitmapset *a);
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extern bool bms_is_empty(const Bitmapset *a);
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/* these routines recycle (modify or free) their non-const inputs: */
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extern Bitmapset *bms_add_member(Bitmapset *a, int x);
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extern Bitmapset *bms_del_member(Bitmapset *a, int x);
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extern Bitmapset *bms_add_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_int_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_del_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_join(Bitmapset *a, Bitmapset *b);
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/* support for iterating through the integer elements of a set: */
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extern int bms_first_member(Bitmapset *a);
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/* support for hashtables using Bitmapsets as keys: */
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extern uint32 bms_hash_value(const Bitmapset *a);
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#endif /* BITMAPSET_H */
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