Re: Inheritance efficiency - Mailing list pgsql-general

From Bruce Momjian
Subject Re: Inheritance efficiency
Date
Msg-id 201004302048.o3UKmsO25945@momjian.us
Whole thread Raw
In response to Re: Inheritance efficiency  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-general
Alvaro Herrera wrote:
> Vincenzo Romano wrote:
>
> > This is not enterprise grade.
>
> "Enterprise grade" is nothing but a buzzword.  Oh, it's also a moving
> target.  We've been not enterprise grade for years, always one feature
> behind (and strangely, the one lacking feature is always the one of
> interest to the complainant).

We do have this enhancement coming in Postgres 9.0:

     Add an index on pg_inherits.inhparent, and use it to avoid seqscans
     in find_inheritance_children().  This is a complete no-op in databases
     without any inheritance.  In databases where there are just a few
     entries in pg_inherits, it could conceivably be a small loss.  However,
     in databases with many inheritance parents, it can be a big win.

However, I don't think this going to help a lot for partitioning because
the cost is mostly checking the CHECK constraints, not finding the
table's children.

Like all Postgres missing features, we just need someone with time to
volunteer to research and fix it.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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