Re: Does PostgreSQL check database integrity at startup?

Em 26/12/2017 13:40, Pavel Stehule escreveu:
>
>
> 2017-12-26 16:37 GMT+01:00 Edson Carlos Ericksson Richter
> <richter(at)simkorp(dot)com(dot)br <mailto:richter(at)simkorp(dot)com(dot)br>>:
>
> Em 26/12/2017 12:25, Pavel Stehule escreveu:
>>
>>
>> 2017-12-26 14:44 GMT+01:00 Martin Marques
>> <martin(dot)marques(at)2ndquadrant(dot)com
>> <mailto:martin(dot)marques(at)2ndquadrant(dot)com>>:
>>
>> El 26/12/17 a las 09:52, Edson Carlos Ericksson Richter escribió:
>> > Recently I had a problem with a base file with size 0 in a
>> standby server.
>> >
>> > This raised one question: does PostgreSQL (9.6.6) check
>> base integrity
>> > at startup?
>> >
>> > At least if there are 0 byte size files in base dir? Or
>> CRC? Something?
>>
>> Yes it has CRC check, but only if you initialize the cluster with
>> --data-checksums, and there's a price to pay in performance.
>>
>>
>> It has CRC check, but it is used in runtime - when data are
>> necessary
>>
>> So Postgres usually check nothing on start - few system tables
>> and indexes
>>
>> Regards
>>
>> Pavel
>>
>>
>> --
>> Martín Marqués http://www.2ndQuadrant.com/
>> PostgreSQL Development, 24x7 Support, Training & Services
>>
>>
>
> Any tips to make database server don't start if corrupt?
> If I can change the startup script to make some checks before
> effectively starting the database, what would be the recommendations?
>
> One that seems obvious to me are empty data files (something like
> "find -size 0 $PG_DATA/base")...
> But I'm sure that more experienced PostgreSQL DBA would have more
> tests to check before startup.
>
>
> I don't think so anybody does it. Reading 1TB database needs more then
> few hours.
>
> Regards
>
>
>
> Thanks,
>
> Edson
>
>
I'm rebuilding the standby server for two days already, with 23% of
completion status...
If lost the database and backups because of that failure, it would be a
giant disaster.
Few hours checking integrity would be acceptable... Specially if I can
run it on standby only.

Regards,

Edson