Re: Error with temporary tables

Claire McLister <mclister@zeesource.net> writes:
> This was all working fine until E.Value became some large strings
> with some occasional funny characters.

> The hack that solved the problem was:

>   R.Field := substring(E.Value from 1);

>   This is a complete hack, so I'd like to find out what is going
> wrong and why this worked. For now, it keeps the system functional.

Oooh.  You were probably dealing with values that had gotten large
enough to be "toasted", ie, stored out-of-line in a TOAST table.
So the datum being passed around in memory was just a pointer to the
row in the TOAST table.  Dropping the temp table made its TOAST table
go away, resulting in a dangling pointer stored in the plpgsql variable.

The easy fix would be to forcibly detoast any value stored into a
plpgsql variable, but the performance implications of that seem a
bit nasty.  Not sure I want to do it for such a weird corner case...

            regards, tom lane