cache lookup failed for function 19119

Hi All

I am using  postgres-8.1.2 .

And getting this error “cache lookup failed for function 19119”.

Can anyone please let me know what could have gone wrong.

How can a function go missing . And which function

Its talkig about ?? its some postgres’s internal function or a user defined function ??

 How can I get function name corresponding 19119

Thanks..

Tamanna