Thread

1. timezone incompatibility

   Winter, Wolfgang <wolfgang.winter@atosorigin.com> — 2002-06-21T06:46:32Z

   Hi,
   
   I'm testing our auto-configuration persistence framework (acp) against
   several databases and now that it comes to PostgreSQL, I run into a timezone
   incompatibility compared to other jdbc-drivers/databases. The framework
   tests the database specific datatypes by inserting a value, retrieving it
   and comparing the result. Here is the result for timestamp:
   
    Insert and Retrieve of SQLType 93 test value <Sun Jun 20 20:16:54 CEST
   1756> failed. Retrieved after insert: <Sun Jun 20 18:16:54 CEST 1756>
   
   I tried it with a test value in 1992 and the test passes.
   Okay, the docs say:
   "PostgreSQL uses your operating system's underlying features to provide
   output time-zone support, and these systems usually contain information for
   only the time period 1902 through 2038 (corresponding to the full range of
   conventional Unix system time)."
   
   But nevertheless, I feel sick with this behaviour, to me it seems not to be
   correct and it makes PostgreSQL incompatible to other databases. The
   databases I have tested so far retrieve the correct date  before 1902.
   
   
   regards
   Wolfgang
   
   
   
   Dr. Wolfgang Winter
   LogiTags Systems
   http://www.logitags.com
   
   

2. Re: timezone incompatibility

   Dave Cramer <dave@micro-automation.net> — 2002-06-21T09:13:30Z

   Wolfgang,
   
   This isn't a jdbc issue, I would try the hackers list, or the general
   list.
   
   Out of curiosity are you using RedHat? They broke time. You can try
   complaining to them if this is the case.
   
   Dave
   On Fri, 2002-06-21 at 02:46, Winter, Wolfgang wrote:
   > Hi,
   > 
   > I'm testing our auto-configuration persistence framework (acp) against
   > several databases and now that it comes to PostgreSQL, I run into a timezone
   > incompatibility compared to other jdbc-drivers/databases. The framework
   > tests the database specific datatypes by inserting a value, retrieving it
   > and comparing the result. Here is the result for timestamp:
   > 
   >  Insert and Retrieve of SQLType 93 test value <Sun Jun 20 20:16:54 CEST
   > 1756> failed. Retrieved after insert: <Sun Jun 20 18:16:54 CEST 1756>
   > 
   > I tried it with a test value in 1992 and the test passes.
   > Okay, the docs say:
   > "PostgreSQL uses your operating system's underlying features to provide
   > output time-zone support, and these systems usually contain information for
   > only the time period 1902 through 2038 (corresponding to the full range of
   > conventional Unix system time)."
   > 
   > But nevertheless, I feel sick with this behaviour, to me it seems not to be
   > correct and it makes PostgreSQL incompatible to other databases. The
   > databases I have tested so far retrieve the correct date  before 1902.
   > 
   > 
   > regards
   > Wolfgang
   > 
   > 
   > 
   > Dr. Wolfgang Winter
   > LogiTags Systems
   > http://www.logitags.com
   > 
   > ---------------------------(end of broadcast)---------------------------
   > TIP 4: Don't 'kill -9' the postmaster
   > 
   > 
   
   
   
   
   

3. timezone incompatibility

   Barry Lind <barry@xythos.com> — 2002-06-21T16:19:21Z

   This isn't a jdbc issue so I am forwarding to general.
   
   --Barry
   
   Winter, Wolfgang wrote:
   
   >Hi,
   >
   >I'm testing our auto-configuration persistence framework (acp) against
   >several databases and now that it comes to PostgreSQL, I run into a timezone
   >incompatibility compared to other jdbc-drivers/databases. The framework
   >tests the database specific datatypes by inserting a value, retrieving it
   >and comparing the result. Here is the result for timestamp:
   >
   > Insert and Retrieve of SQLType 93 test value <Sun Jun 20 20:16:54 CEST
   >1756> failed. Retrieved after insert: <Sun Jun 20 18:16:54 CEST 1756>
   >
   >I tried it with a test value in 1992 and the test passes.
   >Okay, the docs say:
   >"PostgreSQL uses your operating system's underlying features to provide
   >output time-zone support, and these systems usually contain information for
   >only the time period 1902 through 2038 (corresponding to the full range of
   >conventional Unix system time)."
   >
   >But nevertheless, I feel sick with this behaviour, to me it seems not to be
   >correct and it makes PostgreSQL incompatible to other databases. The
   >databases I have tested so far retrieve the correct date  before 1902.
   >
   >
   >regards
   >Wolfgang
   >
   >
   >
   >Dr. Wolfgang Winter
   >LogiTags Systems
   >http://www.logitags.com
   >
   >---------------------------(end of broadcast)---------------------------
   >TIP 4: Don't 'kill -9' the postmaster
   >
   >  
   >
   
   
   
   

4. Re: timezone incompatibility

   lockhart@fourpalms.org — 2002-06-21T22:21:00Z

   > This isn't a jdbc issue so I am forwarding to general.
   
   Hmm. Why is it not a jdbc issue? There is a documented, consistant, and
   altogether reasonable behavior from the database (imho of course ;). If
   there is a Java spec that somehow time zones must be respected for
   decades and centuries when there was no such concept even defined, then
   it would seem to fall on jdbc to implement that idea.
   
   The symptom is that a time from 1756 is entered with an explicit time
   zone. PostgreSQL accepts that. On query, the time is returned in GMT,
   without any claim for a time zone at all:
   
   lockhart=# select timestamp with time zone
   lockhart-# 'Sun Jun 20 20:16:54 CEST 1756';
        timestamptz     
   ---------------------
    1756-06-20 18:16:54
   
   So although the date is not returned with an explicit "GMT" for the time
   zone, it is not claiming to be CEST either.
   
   What different behavior would we need to get JDBC to infer the expected
   result? It may be we need to change *both* JDBC and PostgreSQL, but
   certainly changing just PostgreSQL won't fix the problem (at least
   without introducing troubles for others).
   
                     - Thomas
   
   > >I'm testing our auto-configuration persistence framework (acp) against
   > >several databases and now that it comes to PostgreSQL, I run into a timezone
   > >incompatibility compared to other jdbc-drivers/databases. The framework
   > >tests the database specific datatypes by inserting a value, retrieving it
   > >and comparing the result. Here is the result for timestamp:
   > >
   > > Insert and Retrieve of SQLType 93 test value <Sun Jun 20 20:16:54 CEST
   > >1756> failed. Retrieved after insert: <Sun Jun 20 18:16:54 CEST 1756>
   > >
   > >I tried it with a test value in 1992 and the test passes.
   > >Okay, the docs say:
   > >"PostgreSQL uses your operating system's underlying features to provide
   > >output time-zone support, and these systems usually contain information for
   > >only the time period 1902 through 2038 (corresponding to the full range of
   > >conventional Unix system time)."
   > >
   > >But nevertheless, I feel sick with this behaviour, to me it seems not to be
   > >correct and it makes PostgreSQL incompatible to other databases. The
   > >databases I have tested so far retrieve the correct date  before 1902.
   > >
   > >
   > >regards
   > >Wolfgang
   > >
   > >
   > >
   > >Dr. Wolfgang Winter
   > >LogiTags Systems
   > >http://www.logitags.com
   > >
   > >---------------------------(end of broadcast)---------------------------
   > >TIP 4: Don't 'kill -9' the postmaster
   > >
   > >
   > >
   
   

5. Re: timezone incompatibility

   Barry Lind <barry@xythos.com> — 2002-06-22T03:46:09Z

   OK, I found the bug in the jdbc code.  It was treating a date coming 
   from the server without timezone information as being in the local 
   timezone instead of being in GMT.  I will fix this over the weekend.
   
   thanks,
   --Barry
   
   
   Thomas Lockhart wrote:
   
   >>This isn't a jdbc issue so I am forwarding to general.
   >>    
   >>
   >
   >Hmm. Why is it not a jdbc issue? There is a documented, consistant, and
   >altogether reasonable behavior from the database (imho of course ;). If
   >there is a Java spec that somehow time zones must be respected for
   >decades and centuries when there was no such concept even defined, then
   >it would seem to fall on jdbc to implement that idea.
   >
   >The symptom is that a time from 1756 is entered with an explicit time
   >zone. PostgreSQL accepts that. On query, the time is returned in GMT,
   >without any claim for a time zone at all:
   >
   >lockhart=# select timestamp with time zone
   >lockhart-# 'Sun Jun 20 20:16:54 CEST 1756';
   >     timestamptz     
   >---------------------
   > 1756-06-20 18:16:54
   >
   >So although the date is not returned with an explicit "GMT" for the time
   >zone, it is not claiming to be CEST either.
   >
   >What different behavior would we need to get JDBC to infer the expected
   >result? It may be we need to change *both* JDBC and PostgreSQL, but
   >certainly changing just PostgreSQL won't fix the problem (at least
   >without introducing troubles for others).
   >
   >                  - Thomas
   >
   >  
   >
   >>>I'm testing our auto-configuration persistence framework (acp) against
   >>>several databases and now that it comes to PostgreSQL, I run into a timezone
   >>>incompatibility compared to other jdbc-drivers/databases. The framework
   >>>tests the database specific datatypes by inserting a value, retrieving it
   >>>and comparing the result. Here is the result for timestamp:
   >>>
   >>>Insert and Retrieve of SQLType 93 test value <Sun Jun 20 20:16:54 CEST
   >>>1756> failed. Retrieved after insert: <Sun Jun 20 18:16:54 CEST 1756>
   >>>
   >>>I tried it with a test value in 1992 and the test passes.
   >>>Okay, the docs say:
   >>>"PostgreSQL uses your operating system's underlying features to provide
   >>>output time-zone support, and these systems usually contain information for
   >>>only the time period 1902 through 2038 (corresponding to the full range of
   >>>conventional Unix system time)."
   >>>
   >>>But nevertheless, I feel sick with this behaviour, to me it seems not to be
   >>>correct and it makes PostgreSQL incompatible to other databases. The
   >>>databases I have tested so far retrieve the correct date  before 1902.
   >>>
   >>>
   >>>regards
   >>>Wolfgang
   >>>
   >>>
   >>>
   >>>Dr. Wolfgang Winter
   >>>LogiTags Systems
   >>>http://www.logitags.com
   >>>
   >>>---------------------------(end of broadcast)---------------------------
   >>>TIP 4: Don't 'kill -9' the postmaster
   >>>
   >>>
   >>>
   >>>      
   >>>
   >
   >---------------------------(end of broadcast)---------------------------
   >TIP 5: Have you checked our extensive FAQ?
   >
   >http://www.postgresql.org/users-lounge/docs/faq.html
   >
   >  
   >
   
   
   
   

6. Re: timezone incompatibility

   lockhart@fourpalms.org — 2002-06-22T05:27:24Z

   Barry Lind wrote:
   > 
   > OK, I found the bug in the jdbc code.  It was treating a date coming
   > from the server without timezone information as being in the local
   > timezone instead of being in GMT.  I will fix this over the weekend.
   
   For "timestamptz" aka TIMESTAMP WITH TIME ZONE if it doesn't have a time
   zone then it is GMT. If it is "timestamp" aka TIMESTAMP WITHOUT TIME
   ZONE then they all are in the local time zone.
   
   Does the JDBC driver let you distinguish between all of the cases?
   
                       - Thomas