PL/pgSQL question about EXCEPTION clause & corrupt records

["Nick Renders" <postgres@xxxxxxxxxx>]

Hello,

We recently suffered a database crash which resulted in some corrupt 
records.

I thought I would write a little PL script that would loop through all 
the data and report any inconsistencies. However, I can't get it to work 
properly.

For instance, if I run the following statement in pgAdmin:

	SELECT * FROM f_gsxws_transaction WHERE gwta_number = 762513

I get the following message:

	ERROR:  missing chunk number 0 for toast value 8289525 in 
pg_toast_5572299


So, as a test, I created a function that would just retrieve that one 
record:

	DECLARE
		rcontent f_gsxws_transaction%ROWTYPE;
	BEGIN
		SELECT * INTO rcontent FROM f_gsxws_transaction where gwta_number = 
762513;
	    RETURN rcontent;
	EXCEPTION WHEN OTHERS THEN
		RAISE NOTICE 'Record 762513 is corrupt';
	END;


Now, when I run this function, I have noticed two things:

1) The function has no problem executing the SELECT statement. It is 
only when "rcontents" is returned, that the function fails. This is a 
problem, because the ultimate goal is to loop through all records and 
only return/alert something in case of an error.

2) The function never enters the EXCEPTION clause. Instead, when it hits 
the RETURN command, it breaks and shows the same message as in pgAdmin: 
missing chunk number 0 for toast value 8289525 in pg_toast_5572299.


Is it possible to check for these kind of errors with a PL script? Or is 
there perhaps a better way to check for corrupt records in a database?

Best regards,

Nick Renders