Subject Re: [firebird-support] High CPU use after restore
Author Jardar Maatje

Hi again,

Sounds like a reasonable cause for the problem. So now is my question, what is the best way to upgrade.
My current setup is as follows:
I have two databases, one for raw data (RAW), and the second one for decoded data (MAIN). I need to keep the RAW db with as high availability as possible (or we will loose incoming data). For the MAIN db I have more slack regarding downtime (weekends/nights). They both have ODS version 11.2.

The best would be if I could upgrade to the latest version (2.5.4) of the server db without the need to do backup/restore as this takes a lot of time.

Best regards


29. okt. 2015 00.00 skrev "setysvar setysvar@... [firebird-support]" <>:

Den 28.10.2015 20:56, skrev Jardar Maatje jardar.maatje@... [firebird-support]:
Hi again

A bit more details. I found the query the slows this down and it is a query that includes blob data. If I adjust the query to cast the blob to varchar first the query executes 30 timers faster. I will try to change my queries to fix this.

However I still wonder why this suddenly became a problem after restoring the database.

Best regards

Jardar is a report of a 60-time improvement (from half a minute to half a second) with Firebird 2.5.2/2.5.3 and Jaybird 2.2.5/2.1.6 when changing from blob to varchar, I guess this could be the same problem as you observe.

Could it be that your original database had never before been restored with Firebird 2.5.1, but only with an older Firebird/InterBase version (or never restored, but created with an older Firebird/InterBase version)? If so, then you may have been protected against this particular bug (I'm just guessing, I don't know if older versions have it or not), as well as the bug (only existing in 2.5.1, 2.5.0 and 2.5.2 are OK) that I warned about earlier today regarding indexes containing more than one field (which - I think - can give you wrong results from some queries).