On 2011-02-07, A B <gentosaker@xxxxxxxxx> wrote: > Hello. > > How do you create an index for only some of the rows in a table? I > read in the docs: > > "The expression used in the WHERE clause can refer only to columns of > the underlying table, but it can use all columns, not just the ones > being indexed. Presently, subqueries and aggregate expressions are > also forbidden in WHERE. The same restrictions apply to index fields > that are expressions. " > > So until this changes, can you just add a boolean field to tell if the > column should be used in the index, and then run "create index .... > where use_in_index = true" or are there other (better?) ways of doing > this? the manual section quoted above is not exactly correct, you are also allowed constants, immutable functions and operators. create index foo_bigbar on foo(bar) where quux > 8.6; create index foo_bar_nofred on foo(bar) where fred is null; etc... -- ââ 100% natural -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
