On Sun, Feb 27, 2011 at 12:30 AM, John R Pierce <pie...@hogranch.com> wrote:
> On 02/26/11 10:42 AM, Amitabh Kant wrote: > >> On Sat, Feb 26, 2011 at 11:52 PM, John R Pierce <pie...@hogranch.com<mailto: >> pie...@hogranch.com>> wrote: >> >> On 02/26/11 10:01 AM, Alban Hertroys wrote: >> >> On 26 Feb 2011, at 18:04, Amitabh Kant wrote: >> >> Now if I partition the table T2 based on field T1id, >> making sure that each distinct T1id is provided its own >> child table >> >> Table T2C1 (inherited from T2, T1id field only contains 1 >> for all rows) >> Table T2C2 (inherited from T2, T1id field only contains 2 >> for all rows) >> -- -- >> >> What I would like to know here is that do I need to add an >> index for T1id field for either T2 or it's inherited >> tables (T2C1/T2C2 etc)? >> >> No. Either would be rather pointless. In the child tables all >> the values in that index would have the same exact value, >> which you don't need as constraint exclusion already pointed >> the planner to the right table. In the parent table there >> wouldn't be any data to index. >> >> >> the whole idea of one table per row sounds rather odd and >> pointless to me.<http://www.postgresql.org/mailpref/pgsql-general> >> >> >> >> Not sure I am getting you correctly, but every table will have multiple >> rows of data, but for every row in a given table, the value of the FK would >> be the same. >> > > ah, I misunderstood the original description. > > you're not likely to query T2 by T1id, are you? Doing so would return all > of one of those inherited tables > > Almost all queries will have T1id as one of its parameter, although not the only parameter. Amitabh
