Re: Extract transaction from WAL

Marc Millas <[email protected]>
Newsgroups gmane.comp.db.postgresql.general
Message-ID <CADX_1aa7rOgNdh46-kGKamSJrXtD65JB5RcbpLzepV8Z1AFLag@mail.gmail.com>
Hi,
funny enough, this pb looks similar to mine.
the point is: how to guess: what is the "data I need" ??

Looks like we are looking for a way to ask postgres: which transactions
have occurred between this and that.
Obviously, if we can have, online, both the db after the PITR and the db
"corrupted" we can try to create a dblink from one to the other and, then
try to extract the "differences".

but this is not always possible. hence the question about wals.
or ?

regards,

Marc MILLAS
Senior Architect
+33607850334
www.mokadb.com



On Thu, Nov 21, 2019 at 3:24 PM Michael Loftis <[email protected]> wrote:

>
>
> On Thu, Nov 21, 2019 at 04:56 Jill Jade <[email protected]> wrote:
>
>> Hello everyone,
>>
>> I am new to Postgres and I have a query.
>>
>>  I have updated a table which I should not have.
>>
>>  Is there a way to extract the transactions from the WAL and get back the
>> previous data?
>>
>> Is there a tool that can help to get back the transactions?
>>
>
> The normal way is to use a backup along with point in time recovery. But
> this requires you’ve setup backups and are archiving WALs F/ex with
> pgbackrest. You restore the last full backup from before the incident and
> play back to a time stamp or transaction ID. Either to the original server
> or elsewhere...in this case I would probably restore elsewhere and extract
> the data I needed using tools like pg_dump to restore the selected data.
>
> I’m personally unaware of other methods which may exist.
>
>>
>> Thanks in advance.
>>
>> Regards,
>> Jill
>>
>>
>> --
>
> "Genius might be described as a supreme capacity for getting its possessors
> into trouble of all kinds."
> -- Samuel Butler
>
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