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Indexes with INCLUDE columns and their support in B-tree

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This patch introduces INCLUDE clause to index definition.  This clause
specifies a list of columns which will be included as a non-key part in
the index.  The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans.  Also, such columns don't need to have
appropriate operator classes.  Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.

Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine.  For now, only B-tree indexes support INCLUDE clause.

In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys).  Therefore, B-tree indexes
now might have variable number of attributes.  This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid.  Free 13th bit of t_info is used for indicating
that.  This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.

Bump catalog version

Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
			 David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru
This commit is contained in:
Teodor Sigaev
2018-04-07 23:00:39 +03:00
parent 01bb85169a
commit 8224de4f42
89 changed files with 2112 additions and 467 deletions
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7
src/include/access/itup.h
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@@ -41,7 +41,7 @@ typedef struct IndexTupleData
*
* 15th (high) bit: has nulls
* 14th bit: has var-width attributes
* 13th bit: unused
* 13th bit: AM-defined meaning
* 12-0 bit: size of tuple
* ---------------
*/
@@ -63,7 +63,8 @@ typedef IndexAttributeBitMapData * IndexAttributeBitMap;
* t_info manipulation macros
*/
#define INDEX_SIZE_MASK 0x1FFF
/* bit 0x2000 is reserved for index-AM specific usage */
#define INDEX_AM_RESERVED_BIT 0x2000 /* reserved for index-AM specific
* usage */
#define INDEX_VAR_MASK 0x4000
#define INDEX_NULL_MASK 0x8000
@@ -146,5 +147,7 @@ extern Datum nocache_index_getattr(IndexTuple tup, int attnum,
extern void index_deform_tuple(IndexTuple tup, TupleDesc tupleDescriptor,
Datum *values, bool *isnull);
extern IndexTuple CopyIndexTuple(IndexTuple source);
extern IndexTuple index_truncate_tuple(TupleDesc tupleDescriptor,
IndexTuple olditup, int new_indnatts);
#endif /* ITUP_H */