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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2021-03-26 13:54:29 +0100 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2021-03-26 13:54:30 +0100 |
| commit | ab596105b55f1d7fbd5a66b66f65227d210b047d (patch) | |
| tree | ba03f65e68913c0a684e9483a0c43e0df0229ee3 /src/include/access/transam.h | |
| parent | 77b88cd1bb9041a735f24072150cacfa06c699a3 (diff) | |
BRIN minmax-multi indexes
Adds BRIN opclasses similar to the existing minmax, except that instead
of summarizing the page range into a single [min,max] range, the summary
consists of multiple ranges and/or points, allowing gaps. This allows
more efficient handling of data with poor correlation to physical
location within the table and/or outlier values, for which the regular
minmax opclassed tend to work poorly.
It's possible to specify the number of values kept for each page range,
either as a single point or an interval boundary.
CREATE TABLE t (a int);
CREATE INDEX ON t
USING brin (a int4_minmax_multi_ops(values_per_range=16));
When building the summary, the values are combined into intervals with
the goal to minimize the "covering" (sum of interval lengths), using a
support procedure computing distance between two values.
Bump catversion, due to various catalog changes.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Sokolov Yura <y.sokolov@postgrespro.ru>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
Discussion: https://postgr.es/m/5d78b774-7e9c-c94e-12cf-fef51cc89b1a%402ndquadrant.com
Diffstat (limited to 'src/include/access/transam.h')
| -rw-r--r-- | src/include/access/transam.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/include/access/transam.h b/src/include/access/transam.h index 82e874130d0..2f7338ee827 100644 --- a/src/include/access/transam.h +++ b/src/include/access/transam.h @@ -161,18 +161,18 @@ FullTransactionIdAdvance(FullTransactionId *dest) * development purposes (such as in-progress patches and forks); * they should not appear in released versions. * - * OIDs 10000-11999 are reserved for assignment by genbki.pl, for use + * OIDs 10000-12999 are reserved for assignment by genbki.pl, for use * when the .dat files in src/include/catalog/ do not specify an OID * for a catalog entry that requires one. * - * OIDS 12000-16383 are reserved for assignment during initdb - * using the OID generator. (We start the generator at 12000.) + * OIDS 13000-16383 are reserved for assignment during initdb + * using the OID generator. (We start the generator at 13000.) * * OIDs beginning at 16384 are assigned from the OID generator * during normal multiuser operation. (We force the generator up to * 16384 as soon as we are in normal operation.) * - * The choices of 8000, 10000 and 12000 are completely arbitrary, and can be + * The choices of 8000, 10000 and 13000 are completely arbitrary, and can be * moved if we run low on OIDs in any category. Changing the macros below, * and updating relevant documentation (see bki.sgml and RELEASE_CHANGES), * should be sufficient to do this. Moving the 16384 boundary between @@ -186,7 +186,7 @@ FullTransactionIdAdvance(FullTransactionId *dest) * ---------- */ #define FirstGenbkiObjectId 10000 -#define FirstBootstrapObjectId 12000 +#define FirstBootstrapObjectId 13000 #define FirstNormalObjectId 16384 /* |