Give me an example of HSQLDB corruption!

[f***@atlassian.com]

The documentation on JIRA warns against staying with the shipped Hypersonic database, giving quite strong advice to switch to something more industrial strength. We are migrating from CVSTrac which did us well for a few years, and that just sits on its own little SQL-lite database, and we never had any corruption problems.

Can anyone give me a real example of what terrible thing can happen if we stick with Hypersonic and under what circumstance does it occur?

Cheers!
Rob
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Post by cats - online at:
http://forums.atlassian.com/thread.jspa?forumID=46&threadID=29189

[f***@atlassian.com]

Partial or complete loss of all the data is a distinct possibility. I've seen it several times (not just under Jira though, and with SQL-Lite as well as HSQLDB).

Possible causes I've seen
* Killing a service instead of shutting down cleanly on a Windows machine (hard reboots mostly, but even a "kill" from task manager can do it)
* Developers latest code tried to do something "clever" in the application (Oracle and MySQL threw an error, ignored the commit and carried on, HSQLDB corrupted a table)
* Any form of disk problem, from something writing to the directory with the database file in it inappropriately, through to the day I physically moved my box, dropped it, and the disk took a hard knock
* Buffer overflow on another application overwrote part of the HLSQLDB memory space, which got written to disk and mangled some data.

I've heard that it can corrupt itself if the application server runs out of memory as well, but I've never used a database large enough to cause that.

Most of the time, I imagine you're fine - all of these are exceptions to "normal" working conditions.
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Post by broughn2 - online at:
http://forums.atlassian.com/thread.jspa?forumID=46&threadID=29189

[f***@atlassian.com]

You'd have to be crazy to use HSQL in production, especially given that you can get perfectly good DBMSs like postgreSQL and MySQL for free.

For one thing, you cannot run a SQL query directly against the database, outside of the context of jira. This will be useful for trouble-shooting.

jamie
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Post by JamieEchlin - online at:
http://forums.atlassian.com/thread.jspa?forumID=46&threadID=29189

[f***@atlassian.com]

You can also download for free SQLSERVER Express.
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Post by jmacleod - online at:
http://forums.atlassian.com/thread.jspa?forumID=46&threadID=29189

[f***@atlassian.com]

Thanks guys. Just wanted a little more context to help explain the requirement to the guys doing the planning round here, so we know the relative urgency of this. I think SQL Server has been mentioned, although I've had limited, but good experience with postgreSQL in the past, so I'll push for that if possible.

Good point about the SQL client for queries as well. I think it would definitely help as we bring JIRA onboard to get more familiar under the covers.

I must admit that I hadn't realised Hypersonic was flaky until I saw the Atlassian information.

Cheers!
Rob
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Post by cats - online at:
http://forums.atlassian.com/thread.jspa?forumID=46&threadID=29189