DB versions : 10.2, 11.1 , 11.2.0.4
Platform : RHEL, Oracle Linux 6.XX
Moved this post from Upgrade community to here (General Database discussions) due to less response.
Question1. I gather that , I need to upgrade Timezone file after every DB upgrade.
SQL> SELECT version FROM v$timezone_file;
VERSION
----------
14
What exactly is the timezone file ? Does it store information about DST time changes that happen in countries ?
I understand that the days where clocks need to be set forward or backward are fixed . Right ? I mean, In United States, the DST starts at Second Sunday of March and ends on First sunday of November. In UK, DST starts on 01:00 GMT on last Sunday of March and ends on 01:00 GMT of last Sunday on October.
So, if these 'transition days' are fixed, why do I have to change 'Timezone file' for every DB version upgrade ?
Question2. What happens if I forgot to upgrade the Timezone file during a manual Upgrade ?
Last month, I manually upgraded a 11.1.0.7.0 DB to 11.2.0.4 (Non-Prod DB but still important). I missed the below message from utlu112i.sql (Pre-Upgrade info tool) and didn't run DBMS_DST package after the upgrade. The DB seems to be running fine and no developers have complained so far. But, what are the implications?
WARNING: --> Database is using a timezone file older than version 14.
.... After the release migration, it is recommended that DBMS_DST package
.... be used to upgrade the 11.1.0.7.0 database timezone version
.... to the latest version which comes with the new release.
Question3. If my DB is located in a country where Daylight Savings Time is not used, I don't have to worry about upgrading the timezone file. Right ?
Yes. I have to use DBUA