Re: Disruptive corruption of data during an update

On Thu, 2012-03-29 at 13:49 +0200, Ennio-Sr wrote:

A few minutes ago I wrote: 
---- quote
update command:
--------
mydb=> update bibl set argomento='curatori', autore='DELLA VOLPE Galvano \      (con due capitoli aggiunti e note di)  where n_prog=3285;
mydb'> ';

UPDATE 12845
mydb=>
--------

Having an adequate back-up I think I'll be able to recover the data, but
can someone explain what the hell happened?

-------- unquote

Having come out of the initial panic I reconsidered the thing with calm
and of course 'discovered' that the program has done exactly what I told
it to do, as the 'where' clause was incorporated within the two «'».

My question now is: 
is there any possibility to recover such type of error while postgres is
still running and no other transacion has been committed?

I cannot help with the recovery, but as a general rule I tend to place all updates/deletes within an explicit transaction. Obviously you can then rollback the transaction should the results not be as required.

dev_reinsure=# begin;
BEGIN
dev_reinsure=# update address set addrLine1='N where recno=2';
UPDATE 911
dev_reinsure=# rollback;
ROLLBACK

Regards,    ennio

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