Dear Postgresql experts,
I have a base table that declares a primary key spanning a couple of columns:
create table B ( id integer, xx someothertype, ..... primary key (id, xx)
);
and a number of derived tables that inherit from B:
create table T (....
) inherits (B);
An index is automatically created for B because of the primary key.
If I search for something in T using the key columns, e.g. I do
select * from T where id=1 and xx=something;
will the index be used? Or must I explicity create an index on id and xx for T and each of the other derived tables?
Is it any different if I search in B and find rows that are actually in T?
(Slightly unrelated: does the index on (id,xx) help when I am searching only on id?)
Thanks for any insight anyone can offer.
--Phil.
