Re: Does PostgreSQL check database integrity at startup?

Em 26/12/2017 13:57, Pavel Stehule escreveu:
>
>
> 2017-12-26 16:50 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 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.
>
>
> very simple check
>
> pgdumpall > /dev/null
>
> but this doesn't check indexes.
>
> Regards
>
> Pavel
>
>
>
I'll check it and make some tests.
Thanks!

Edson