PostgreSQL 9.0 Released

PostgreSQL version 9.0 was released yesterday (Sept 20th). The 9.0 version of PostgreSQL includes a number of important new features, more new features in fact than any previous release.

Some of the new features found in 9.0 are:

• Streaming Replication - This allows one or more databases to be replicated from a primary database. The replication is asychronous but the lag between replications is short. Note that other 3rd party solutions for this have existed for some time.
• Hot Standby - This allows a second (duplicate) database to be designated as a standby in case the primary database goes down for some reason. The standby can also be used for read-only queries when the primary database is active, thereby providing a bit of load balancing. HotStandby works well with the new Streaming Replication feature.
• In-Place Upgrade - Using the pg_upgrade module databases created with older versions of PostgreSQL can be upgraded in-place without the need to dump and reload the database.
• Support for 64-bit Windows - For those of you that are familiar with whatever this "Windows" thing is.

For more on the new features of PostgreSQL see the release notes and the what's new wiki page.

I had an opportunity to talk to Robin Schumacher of EnterpriseDB and Josh Berkus of the PostgreSQL community. EnterpriseDB is a company that provides commercial versions of PostgreSQL. EnterpriseDB refers to itself as "The Enterprise Postgres Company." One of the things that I didn't realize about PostgreSQL is that it's not GPL licensed, rather it's licensed under the PostgreSQL License which is a license similar to the BSD or MIT licenses.

I asked a couple of minor things before I got to the big question:

• I asked about the usage figures for the different embedded languages available in PostgreSQL. PostreSQL has a built-in procedural programming language called PL/pgSQL, but it also supports extensions that allow you to use other languages such as Perl, Python, and Tcl (PL/Perl, PL/Python, and PL/Tcl respectively). Others may exist, but these are the ones documented with PostgreSQL itself. According to an onsite survey from a few years ago, PL/pgSQL is used by a bit more than half of all developers and the others have low double digit percentage usage.
• I also asked about the number of contributors that PostgreSQL has. Josh put that number at somewhere around 100 for core contributors and another 150 that contribute in other ways. He also mentioned that the project has been reorganizing itself to make it easier to contribute.
• And of course I asked about code size. Currently, PostgreSQL consists of about 300-400K lines of code.

Finally, I got to the big question, which was "How does PostgreSQL measure up against Oracle as an enterprise database?" Robin and Josh's answers follow:

Robin Schumacher (EnterpriseDB):

From an EnterpriseDB perspective, we're the leaders in providing an Oracle compatibility layer that people can use to run their Oracle applications on Postgres with little to no changes. Companies like IBM and Netezza use our Oracle compatibility layer inside their products to enable the same type of functionality.

With our Postgres Plus Advanced Server, we have everything from mirrored Oracle core features, support for Oracle's PL/SQL language, built in Oracle SQL packages, Oracle data dictionary and performance diagnostic compatibility, and more that lets database professionals use Advanced Server instead of Oracle as their database. We also support replicating data from Oracle to Postgres Plus Advanced Server so users can offload Oracle transactional data for reporting or other purposes on a more cost effective platform.

Josh Berkus (PostgreSQL community):

The limited benchmark results we have available, such as the SpecJAppserver benchmark published in 2007, indicate that performance on the two database systems is very similar, and that differences in performance are not enough to prevent migration. Beyond that, each database system has its strengths. Certainly, hundreds of users have migrated applications from Oracle to PostgreSQL successfully, and hundreds more work in a hybrid PostgreSQL-Oracle environment.

PostgreSQL 9.0 is superior for:

• Integration with 3rd-party open source tools
• Ability to extend functionality for specialized needs (such as biotech, security, or marketing analytics)
• Virtualized (cloud) deployments

Oracle 11 is superior for:

• Compatibility with existing proprietary vendor tools
• OLAP business intelligence
• Monitoring and administration tools

The last point is one which the PostgreSQL community is working actively on; each recent annual release has added several new or easier-to-use tools for monitoring and administration. Your primary reader audience will be particularly interested in the tools designed to integrate with Linux, such as pgTop (now available for Android as well) and pgFincore.

See the download page on the PostgreSQL site for more information on getting the new 9.0 version of PostgreSQL.