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" <[EMAIL PROTECTED]> To: "Alexander Priem" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Friday, August 29, 2003 10:57 AM Subject: Re: [PERFORM] Indexing question > > create index orad_id_index on orderadvice (orad_id) where orad_deleteddate > > 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 these > > 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 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html