Re: Driver behaves differently with prepareThreshold and timestamp fields when daylights is active (was Re: Re: 9.4-1207 behaves differently with server side prepared statements compared to 9.2-1102)

Warning:

This only happens if your country has Daylights Saving Time active.
In Brazil, default timezone is GMT-03:00. Currently in DST, the timezone
is GMT-02:00.
This seems to affect some kind of value conversion, and subtract 1 hour
from timestamp values.

Atenciosamente,

Edson Carlos Ericksson Richter

Em 11/01/2016 14:15, Edson Richter escreveu:
> I'm using 1201 driver. No matter JDK 7 or JDK 8.
> Big real issue for me: after third query, the prepareThresold is hit,
> and timezone data is converted "on the fly" to "timezone without
> daylights" for timestamp fields.
> Data is stored in database as "2015-09-30 00:00:00", in the 1st to 3rd
> query returns with "2015-09-30 00:00:00", and the 4º and on returns
> "2015-09-29 23:00:00".
>
> Disabling with prepareThreshold=0 solved the problem once for all.
> I had no further time to investigate and/or produce a case for asking
> for a fix.
>
> Regards,
>
> Atenciosamente,
>
> Edson Carlos Ericksson Richter
>
> Em 11/01/2016 12:14, Vladimir Sitnikov escreveu:
>>> In my case, problema is that after optimization at server side,
>>> results get different.
>> Do you mean "wrong results" kind of issue?
>> which driver version are you using?
>>
>> Generally speaking, it is worth submitting "bad performance when using
>> prepared statements" issues to PostgreSQL hackers team.
>> If just a couple of SQLs behave badly due to server-prepared
>> statements, then it might make sense just tune the statements in
>> question.
>> Vladimir
>>
>>
>
>
>