On 2003-03-31 10:48:05 +0200, Peter Conrad wrote: > Certain java.sql.Timestamp values aren't written to (or retrieved from) > the database correctly. Timestamps affected are in the time interval just > before switchover from DST to non-DST (the bug was noticed on > October 27th 2002 for the first time, when the switchover from MET/DST to MET > took place). Various timestamp values in the range > 2:00 AM - 2:59:59 AM (MET/DST) on October 27th 2002 as well as on October > 26th 2003 have been verified to reproduce the bug, with the database as > well as the JDBC client running in MET. [...] > Timestamp problem = new Timestamp(1067130000000L); // 26.10.03 02:00 MET/DST
That's a general problem with daylight savings time. On the switch from
DST to standard time, one hour (02:00:00 .. 03:00:00 in the case of MET)
occurs twice. If a timestamp is stored in the local timezone but without
timezone information, this information is ambiguous.
This is not Oracle-specific but would happen with any database which
stores timestamps in "human readable" form without timezone information.
If you need to store unambiguous timestamps, use UTC or a numeric
"units since the epoch" format (like POSIX time_t or Java millis).
What's nasty about your sample code is that you specify the timestamp in
Java millis, but it isn't stored that way. It is easy for a programmer
to forget about the type conversion and possible loss of information.
hp
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_ | Peter J. Holzer | Unser Universum w�re betr�blich
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