You could also look into a filtered index that perhaps only covers dates earlier than a certain point in time where regular performance wouldn't be hindered. But Gavin is absolutely right otherwise.
On Jan 5, 2014 5:22 PM, "Sergey Konoplev" <gray...@gmail.com> wrote: > > On Sun, Jan 5, 2014 at 2:19 PM, Gavin Flower > <gavinflo...@archidevsys.co.nz> wrote: > > On 06/01/14 11:08, Sergey Konoplev wrote: > > [...] > > > >> An index might be considered as useless when there were no idx scans for > >> the significantly long period. However it might be non-trivial to define > >> this period. Eg. one have a query building an annual report that uses this > >> index and the period here is one year. > > > > [...] > > > > An index only used by an annual report, should possibly be only created > > prior to the report run & dropped immediately afterwards - why carry its > > overhead for the bulk of the year? > > I fully agree. This is the matter of implementation. > > -- > Kind regards, > Sergey Konoplev > PostgreSQL Consultant and DBA > > http://www.linkedin.com/in/grayhemp > +1 (415) 867-9984, +7 (901) 903-0499, +7 (988) 888-1979 > gray...@gmail.com > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general
