On Mon, Oct 14, 2013 at 10:55 AM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> Soroosh Sardari <soroosh.sard...@gmail.com> writes: > > I developed a new character string type, named myvarchar. > > Also an operator class for btree is added. > > PROBLEM: > > When I executed a query with where clause on 'mine' column, PG does not > use > > index. > > Most likely you got the opclass definition wrong. Since you've shown us > no details of what you did, it's hard to speculate about just how. But > note that varchar itself is a pretty bad model for a user-added datatype, > because it has a special symbiotic relationship with type "text" (to wit, > it has no operators of its own but uses text's operators via implicit > casts). To get to a working independent datatype like this, you'd need > to pick the right aspects of each of text and varchar to clone. So my > unfounded speculation is you didn't do that just right. > > regards, tom lane > As Tom said, I did something wrong when I was creating new operators. The RESTRICT parameter is forgotten. Since all varchar operations redirected to text operators, hence my operators must be like operators of type text. I used following command to find text operator: select * from pg_operator where oprleft = 25 and oprright = 25 P.S : 25 is oid of text type. Cheers, Soroosh Sardari
