Re: Unique operator error w/ concatenation

Wells Oliver <woliver@padres.com> writes:
> Folks, experiencing an odd issue. The following on an 8.4 server: select 'foo'::text || 123
> Blows up, saying:

> ERROR:  operator is not unique: text || integer
> LINE 1: select 'fo'::text || 123;
>                           ^
> HINT:  Could not choose a best candidate operator. You might need to add explicit type casts.

> But on another postgres 8.4 server, it properly returns a concatenated string.

> Any tips on how/where I can track down why/where there might be duplicate operators?

psql's "\do ||" might help.  Presumably somebody's stuck a user-defined
operator named || into that database ...

            regards, tom lane