Sun-PostgreSQL win takes swing at Linux, Oracle

Since announcing its intention to contribute to and support the open source PostgreSQL database on its flagship Solaris 10 operating system in late 2005, Sun Microsystems has published a customer win that pulls no punches towards Linux and Oracle.

In a document published on Sun's Web site, the company outlines one customer's transition from Oracle to PostgreSQL and how it chose Solaris 10 over Linux resulting from a failed test project.

The customer, "a large database marketing firm", was serviced by Maryland-based open source consultancy OmniTI.

In its report, Sun claims OmniTI's move from a proprietary application to PostgreSQL for its customer was prompted by growing database requirements that were "threatening to send software costs skyrocketing".

The company's existing half-terabyte OLTP was peaking at 10,000 transactions per second and its data warehouse was consuming 1.2 terabytes of data.

"Scaling the proprietary database application for the OLTP and data warehouse operations would be extremely expensive in light of the application's per-processor licensing requirements," according to Sun. "The open source PostgreSQL database application, on the other hand, had no licensing costs."

Due to the amount of engineering effort required to migrate both database systems, OmniTI decided to only migrate the Oracle-Perl data warehouse to PostgreSQL and keep the OLTP system running Oracle 8i.

"Because Oracle licensing would no longer be needed for the data warehouse, OmniTI moved those Oracle 8i licences to the OLTP, mitigating the costs of scaling the Oracle installation for the OLTP," according to the report.

Sun also took the opportunity to berate Linux by reporting OmniTI initially ran the new PostgreSQL application on 64-bit Linux, but the customer suffered "unacceptable downtime and eventually catastrophic data losses in that environment".

"OmniTI attributes these outages to a number of specific issues associated with the Linux operating system, such as frequent kernel-panic errors, file systems remounting as read-only, and the lack of reliable support for file system snapshots," according to Sun. "After suffering 20 outages in four months on Linux, OmniTI switched to Solaris 10. Since then, the operating environment has been significantly more reliable and stable."

This was confirmed by OmniTI principal and CTO Theo Schlossnagle on his personal blog.

Schlossnagle said during testing the large PostgreSQL data mount point suddenly went read-only on CentOS 4 (a Red Hat derivative) with the ext3 file system.

"So, naturally, I tried to fix the problem by umounting and mounting again, all to no avail," he said. "It turns out that a reboot was required to rectify the issue. While this was disturbing, we rebooted and continued on with life. The more annoying issue was the subsequent 18 times this occurred. The show stopper was the 20th time it failed; upon reboot I found catastrophic data loss."

That said, Schlossnagle also runs a lot of Linux, and BSD and believes there isn't a perfect operating system but Solaris, with its ZFS file system, does "really mesh well with core database needs".

Vendor and operating system politics aside, the real winner appears to be the "large database marketing firm" which experienced a $US400,000 one-time saving and $US100,000 in annual savings on software licensing as a result of the migration, according to Sun.

So far, Schlossnagle is very happy with the new system, which also combines MySQL for data imports and exports, and praised Sun's focus on testing and stability.