EM 13.4: Support for DST Enabled Databases in Fleet Maintenance (Doc ID 2725653.1)

Last updated on APRIL 23, 2024

Applies to:

Goal

Fleet Maintenance is a centralized mechanism for Patching/Upgrading of Oracle Homes and maintain consistency. This document lists how to Upgrading the Time Zone Data Using the DBMS_DST Package using Fleet Maintenance Activity.

Daylight Saving Time (DST) Transition Rules Changes

Governments can and do change the rules for when Daylight Saving Time takes effect or how it is handled. When this occurs, Oracle provides a new set of transition rules for handling timestamp with time zone data.Transition periods for the beginning or ending of Daylight Saving Time can potentially introduce problems (such as data loss) when handling timestamps with time zone data. Oracle has provided the PL/SQL package DBMS_DST and the utltz_* scripts to deal with this transition.

The changes to DST transition rules may affect existing data of TIMESTAMP WITH TIME ZONE data type, because of the way Oracle Database stores this data internally. When users enter timestamps with time zone, Oracle Database converts the data to UTC, based on the transition rules in the time zone file, and stores the data together with the ID of the original time zone on disk. When data is retrieved, the reverse conversion from UTC takes place.

Solution

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