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| author | Tom Lane | 2021-04-05 22:41:09 +0000 |
|---|---|---|
| committer | Tom Lane | 2021-04-05 22:41:21 +0000 |
| commit | 09c1c6ab4bc5764dd69c53ccfd43b2060b1fd090 (patch) | |
| tree | 0b5eacefe5007d52388f475499b018cccd228c0e /doc/src/sgml/spgist.sgml | |
| parent | 49f49defe7c0a330cca084de5da14ccdfdafc6a3 (diff) | |
Support INCLUDE'd columns in SP-GiST.
Not much to say here: does what it says on the tin.
We steal a previously-always-zero bit from the nextOffset
field of leaf index tuples in order to track whether there
is a nulls bitmap. Otherwise it works about like included
columns in other index types.
Pavel Borisov, reviewed by Andrey Borodin and Anastasia Lubennikova,
and rather heavily editorialized on by me
Discussion: https://postgr.es/m/CALT9ZEFi-vMp4faht9f9Junb1nO3NOSjhpxTmbm1UGLMsLqiEQ@mail.gmail.com
Diffstat (limited to 'doc/src/sgml/spgist.sgml')
| -rw-r--r-- | doc/src/sgml/spgist.sgml | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml index 054234784fa..cfb2b3c836f 100644 --- a/doc/src/sgml/spgist.sgml +++ b/doc/src/sgml/spgist.sgml @@ -217,6 +217,14 @@ </para> <para> + When an <acronym>SP-GiST</acronym> index is created with + <literal>INCLUDE</literal> columns, the values of those columns are also + stored in leaf tuples. The <literal>INCLUDE</literal> columns are of no + concern to the <acronym>SP-GiST</acronym> operator class, so they are + not discussed further here. + </para> + + <para> Inner tuples are more complex, since they are branching points in the search tree. Each inner tuple contains a set of one or more <firstterm>nodes</firstterm>, which represent groups of similar leaf values. |