Re: BUG #14621: ERROR: compressed data is corrupt

lara(dot)schembri(at)nyxgg(dot)com writes:
> Currently I'm trying to archive an old table is not being used and during
> the pg_dump the below error was given
> ERROR: compressed data is corrupt

> I have identified that a text coloumn of the ctid (74127541,3) was
> corrupted. This was done by doing a full table scan and wait for that error.
> However, I would like to know how extensive this corruption is. Is there a
> way to be able to extract all the corrupted CTID's and ignore them from the
> copy.

> Please note i have tried the chk function
> declare t text;
> begin t := $1;
> return false;
> exception when others then return true;
> end;

> which did not work.

You would get better responses if you defined what you meant by "did not
work", but I'm going to guess that the issue is that this code failed to
expose corrupted data. That's probably because it would have just
assigned the bad datum to "t" without decompressing it. I'd try something
that would require examination of the actual content of the string,
perhaps "t := md5($1)".

regards, tom lane