Right now I’m working on some internal documentation and referencing Oracle 11g’s Storage Administrators Guide (ASM manual). And I think there’s a bit of a contradiction here about the stripe size. ASM uses a variable “data extent” size when allocating space for files (like any sane filesystem) – the first 20000 data extents are equal to the diskgroup allocation unit (AU), the next 20000 are AU*8, etc. But it’s a little unclear to me how the stripe size is determined. Seems to me that you’d stripe “data extents” rather than allocation units and I think I’ve even heard before that “extents are mirrored [and presumably striped]” in ASM. In fact the illustration in the manual shows the stripes in exactly that manner:

ASM Extents

However the manual states that the opposite is true – striping based on AU instead of data extent – in two different places on that page. › Read more

This article isn’t directly database-related, but I think it’s a great software engineering topic so it seemed worth writing about. Right now I’m involved in a project that involves releasing software packages of a few different flavors. Some of them are other people’s software that we’re re-packaging (like oracle database binaries) and some are code that was completely written and is maintained in-house. And as we’ve been working through the software development process this question has recently come to mind: how should we assign version numbers?

Actually it’s part of a bigger question of how we develop elegant software – other related design issues in this project are clear end-to-end traceability (requirement -> source code version -> released binary package), solid change control, integrated testing framework and readiness for automation (build and test). But the one I’m interested in right now is this: how can I develop a robust version numbering strategy?

First of all, there really isn’t a one-size-fits-all “correct” version numbering scheme. The best way to choose version numbers is influenced by your software development philosophy (and resultant development lifecycle), project management approach and development team. (Globally distributed informal volunteer network or local engineers on payroll?) So the best solution for my current project might not be the best solution for my next project.

But lets take a closer look at this project. First, a little background on the art of version numbering. › Read more