mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Mention partitioned indexes in "Data Definition" chapter

Browse Source 
We can now create indexes more easily than before, so update this
chapter to use the simpler instructions.

After an idea of Amit Langote.  I (Álvaro) opted to do more invasive
surgery and remove the previous suggestion to create per-partition
indexes, which his patch left in place.

Discussion: https://postgr.es/m/eafaaeb1-f0fd-d010-dd45-07db0300f645@lab.ntt.co.jp
Author: Amit Langote, Álvaro Herrera
This commit is contained in:
Alvaro Herrera 2018-02-10 10:01:37 -03:00
parent 935dee9ad5
commit fad15f4a54
1 changed files with 8 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
doc/src/sgml/ddl.sgml
View File

@ -3145,18 +3145,15 @@ CREATE TABLE measurement_y2006m02 PARTITION OF measurement
<listitem>
<para>
Create an index on the key column(s), as well as any other indexes you
might want for every partition. (The key index is not strictly
might want, on the partitioned table. (The key index is not strictly
necessary, but in most scenarios it is helpful. If you intend the key
values to be unique then you should always create a unique or
primary-key constraint for each partition.)
primary-key constraint for each partition.) This automatically creates
one index on each partition, and any partitions you create or attach
later will also contain the index.
<programlisting>
CREATE INDEX ON measurement_y2006m02 (logdate);
CREATE INDEX ON measurement_y2006m03 (logdate);
...
CREATE INDEX ON measurement_y2007m11 (logdate);
CREATE INDEX ON measurement_y2007m12 (logdate);
CREATE INDEX ON measurement_y2008m01 (logdate);
CREATE INDEX ON measurement (logdate);
</programlisting>
</para>
</listitem>
@ -3273,12 +3270,9 @@ ALTER TABLE measurement ATTACH PARTITION measurement_y2008m02
<itemizedlist>
<listitem>
<para>
There is no facility available to create the matching indexes on all
partitions automatically. Indexes must be added to each partition with
separate commands. This also means that there is no way to create a
primary key, unique constraint, or exclusion constraint spanning all
partitions; it is only possible to constrain each leaf partition
individually.
There is no way to create a primary key, unique constraint, or
exclusion constraint spanning all partitions; it is only possible
to constrain each leaf partition individually.
</para>
</listitem>