Re: regclass without error?

Excerpts from David Fetter's message of vie sep 03 10:21:00 -0400 2010:

> > How about using a SAVEPOINT before the cast?  Wouldn't fail your
> > transaction..
> 
> For unattended operation, there are some issues:
> 
> * Generating appropriate SAVEPOINT names
> * Keeping track of same
> * Detecting errors
> * Issuing ROLLBACKs to the aforementioned SAVEPOINT
> 
> None of this works super well for a bulk load.

Why do you need any of this?  The logic is pretty simple:

SAVEPOINT my_savepoint;
select ...::regclass;

-- if it works
RELEASE my_savepoint;

-- if it fails
ROLLBACK TO my_savepoint;
RELEASE my_savepoint;


Granted, it's not super-performant ...

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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