11g Database Upgrade Options

11g Database Upgrade Options 

The next several Blog entries will be centered on research that I conducted on the possible upgrade options when moving the system to new hardware on both the production and backup servers.

Today we briefly look a some of the options available and I ranked them from  1-5 in  several areas.
 

The simplest upgrade to perform is by installing 11g software on the same server as the 10g instance resides and upgrade the datafiles in place.  The time it takes to upgrade in this manner does not depend on the size of the database but rather the options installed (partitioning, xml, ect.). If all pre-upgrade tasks are completed before the actual time of the upgrade then a database upgrade using Database Upgrade Assistant usually runs between 30 and 90 minutes. There are methods of moving a database to 11g that can either increase or dramatically decrease this downtime. Some of them involve running the DBUA or manually running upgrade scripts and some do not. This paper highlights some of the different options available. They can be modified and adjusted according to needs but the general steps are outlined.

The following table summarizes the upgrade methods and rates them (1 to5) in several areas.  The difficulty in setup describes how hard it would be to setup the scenario. The higher the difficulty means that there is more that needs to be organized between teams, communicated, work done on both the current operations environment (OE) and rehost operations environments (ROE). The usability for testing measures how difficult it would be to use the environment for testing transactions multiple times. The higher the difficulty means that there is more preliminary setup, steps to assure recoverability to designated point in times, or steps to create a repeatable process. The higher the execution difficulty relates to the complexity the actual upgrade process including tasks that need to be performed by non-dbas involved with migrating to 11g on the day of cutover. The fallback ability describes how difficult it would be to fall back to the OE 10g environment. As an example a 1 would indicate that you just need to point the clients to the OE system. A 5 would indicate you would need to recover from a previous backup. The final column estimated down time is just a SWAG (Scientific Wild Butt Guess) on how long the database would be unusable. This can be adjusted as testing occurs.

Method	Difficulty in Setup	Usability for Testing	Execution Difficulty	Fallback Ability	Estimated Down Time Guess
Datapump Import / Export	2	3	2	1	??? Depends on dataset size
Transportable Tablespaces	2	Not an Option	2	2	60 Minutes
Logical Standby Database	4	1	1	1	Less than 15 minutes
Upgrade using DBUA	2	Not an Option	3	5	Depends on options installed 30- 90 minutes
Upgrade using command line interface	2	Not an Option	5	5	Depends on options installed 30- 90 minutes
Physical Standby	4	3	2	1	Depends on options installed 30- 90 minutes
Oracle Streams / Golden Gate (not really considered because of cost / setup)	>5	5	3	1	Less than 15 minutes