Skip site navigation (1) Skip section navigation (2)

Re: Indexing question

From: "Alexander Priem" <ap(at)cict(dot)nl>
To: "Tomasz Myrta" <jasiek(at)klaster(dot)net>
Cc: <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Indexing question
Date: 2003-08-29 09:08:21
Message-ID: 01bf01c36e0d$18769280$b696a8c0@APR (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
The first index is for sorting on orad_id, the second one for sorting on
orad_name. The first one would be useful for queries like 'select * from
orderadvice_edit where orad_id=100', the second one for queries like 'select
* from orderadvice_edit order by orad_name'. Right?

Does anyone know whether it is bad practise to have two indexes on the
primary key of a table? (one 'primary key' index and one partial index)

----- Original Message -----
From: "Tomasz Myrta" <jasiek(at)klaster(dot)net>
To: "Alexander Priem" <ap(at)cict(dot)nl>
Cc: <pgsql-performance(at)postgresql(dot)org>
Sent: Friday, August 29, 2003 10:57 AM
Subject: Re: [PERFORM] Indexing question

> > create index orad_id_index on orderadvice (orad_id) where
> > is null;
> > create index orad_name_index on orderadvice (orad_name) where
> > orad_deleteddate is null;
> >
> > create view orderadvice_edit as select
> > orad_id,orad_name,orad_description,orad_value,orad_value_quan from
> > orderadvice where orad_deleteddate is null;
> >
> > Would queries like 'select * from orderadvice_edit where orad_id=100' or
> > 'select * from orderadvice_edit order by orad_name' both use one of
> > two partial indexes, given enough records are present in the table?
> >
> > There would be a double index on the primary key this way, right?
> It looks much better now. I'm not sure about the second index. Probably
> it will be useless, because you sort ALL records with deleteddtata is
> null. Maybe the first index will be enough.
> I'm not sure what to do with doubled index on a primary key field.
> Regards,
> Tomasz Myrta
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend

In response to


pgsql-performance by date

Next:From: Ron JohnsonDate: 2003-08-29 12:05:36
Subject: Re: Hardware recommendations to scale to silly load
Previous:From: Tomasz MyrtaDate: 2003-08-29 08:57:25
Subject: Re: Indexing question

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group