As yesterday was April 1st, All Fool’s Day, I decided to wait a day or so before posting on the new free Oracle database edition: 11g XE beta. It is in fact out and downloading it took me less than 1 minute even via my slow wireless connection.
You can download it from http://www.oracle.com/technetwork/database/express-edition/11gxe-beta-download-302519.html and install it after accepting the license agreement:
You probably often click the “Accept” button and then “Next” but this time I decided to read the entire “Oracle Database Express Edition License Agreement”. You will also probably end up with some open questions. Just one example:
During installation, while reading the agreement you will see: “You may make one copy of the programs for backup purposes.” If you check the oracle.com license information, it says: “You may make a reasonable number of copies of the programs for backup purposes.”. But we should not forget that we are talking about a beta release of the software, so many things are to be fixed.
I would like to comment on two main things: restrictions and 11g upgrade.
1. 11g XE main restrictions and limitations:
- if Oracle Database XE is installed on a computer with more than one CPU (including dual-core CPUs), then it will consume, at most, processing resources equivalent to one CPU.
- only one installation of Oracle Database XE can be performed on a single computer which does not affect any existing installation or new installations of Oracle Database 11g Standard Edition, Oracle Database 11g Standard Edition One, or Oracle Database 11g Enterprise Edition. In addition, users can run only one instance of the Oracle Database XE database on each individual computer.
- the maximum amount of user data in an Oracle Database XE database cannot exceed 11 gigabytes compared to 4 gigabytes on 10g XE. If the user data grows beyond this limit, then an ORA-12592 error will appear. Note that 11G is just user data!
- the maximum amount of RAM that an Oracle Database XE database uses cannot exceed 1 gigabyte, even if more is available. The exact amount of RAM that Oracle Database XE uses is the sum of the System Global Area (SGA) and the aggregate Program Global Area (PGA).
- HTTPS is not supported natively with the HTTP listener built into Oracle Database XE.
- the list of all features not available with 11g XE is here. It is a rather long list and XE lacks lots of important stuff realted to HA, performance, securty, replication and DBAism.
2. Upgrade from 10g XE to 11g XE:
- copy the gen_inst.sql file from the upgrade directory of 11.2 XE home to some local directory
- connect to 10.2 XE database as SYS and run gen_inst.sql thus generating install.sql, gen_apps.sql and other .sql files in the local folder containing gen_inst.sql
- export the data from 10.2 XE database
- deinstall 10.2 XE if installation of 11.2 XE is planned on the same computer
- install the 11.2 XE database
- import the data into the 11.2 XE database
- connect to 11.2 XE database as SYS user and run the script install.sql, which was generated after running gen_inst.sql
The most important benefits of 11g XE are (as I see them):
A. Save from license costs by keeping small databases on top of XE. In case, you can live with the limitations of course.
B. On more global terms, you can use 11g XE for Database Sharding. 11 gigabytes of user data is quite sufficient for one shard! When it grows above say 10G, you will split it into at least two new shards.
P.S. Will 12g XE have the limitation of 12 gigabytes of user data :-) ?