Auto-indexing

* Christopher Kings-Lynne <chriskl@familyhealth.com.au> [010206 18:29] wrote:

Is it a feasible idea that PostgreSQL could detect when an index would be
handy, and create it itself, or at least log that a table is being queried
but the indices are not appropriate?

I suggest this as it's a feature of most windows databases, and MySQL does
it. I think it would be a great timesaver as we have hundreds of different
queries, and it's a real pain to have to EXPLAIN them all, etc. Is that
possible? Feasible?

Probably both, but if it's done there should be options to:

.) disable it completely or by table/database or even threshold or
disk free parameters (indicies can be large)
.) log any auto-created databases to inform the DBA.
.) if disabled optionally log when it would have created an index on
the fly. (suggest an index)
.) expire old and unused auto-created indecies.

Generally Postgresql assumes the user knows what he's doing, but
it couldn't hurt too much to provide an option to have it assist
the user.

--
-Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org]
"I have the heart of a child; I keep it in a jar on my desk."

Probably both, but if it's done there should be options to:

.) disable it completely or by table/database or even threshold or
disk free parameters (indicies can be large)
.) log any auto-created databases to inform the DBA.
.) if disabled optionally log when it would have created an index on
the fly. (suggest an index)
.) expire old and unused auto-created indecies.

Generally Postgresql assumes the user knows what he's doing, but
it couldn't hurt too much to provide an option to have it assist
the user.

I want to implement a SET PERFORMANCE_TIPS, hopefully for 7.2:

* Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
ANALYZE, and CLUSTER

I think suggesting items to the adminstrator is the way to go.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
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