VM's consumes resources, so it can affect performance, specially I/O.

I think the first thing you should do is to install IB and FB in the exactly same environment and check if they really have that performance diference you talked about.

Carlos
Firebird Performance in Detail - http://videos.firebirddevelopersday.com
www.firebirdnews.org - www.FireBase.com.br

Forgot to mention both servers (FB and IB) are on virtual machines over KVM. Both VMs have the same resources and same linux distro installed. They have linux 64 bit and I installed FB2.5.4 SS 32bit. Could be any issue related to bad performance of FB over KVM? I'll also try to put FB on a phisical server to see if it behaves better. 2015-09-05 14:40 GMT+02:00 'Carlos H. Cantu' listas@... [firebird-support] <firebird-support@yahoogroups.com>:   Just curious, when you said IB took 40 seconds, were you using the same machine that you are using with Firebird? If don't so, can you try it and report the result? []s Carlos www.firebirdnews.org - www.FireBase.com.br He again Alexey, As I suspected, my problem is not caused by GC: gstat over the table reported this: TABLE1 (503)   Primary pointer page: 9374, Index root page: 9375   Average record length: 317.63, total records: 3261775   Average version length: 0.00, total versions: 0, max versions: 0   Data pages: 304880, data page slots: 304880, average fill: 90% Also, as you suggested ran the query twice a got exaclty the same times: 51minutes to complete!!! I must have something obvious which is killing firebird performance, but cannot guess it. Any help would be appretiated. 2015-09-05 11:59 GMT+02:00 Alexey Kovyazin ak@... [firebird-support] <firebird-support@yahoogroups.com>: Hi Hector, So you finally decided to try Firebird - that's good. I think that you are facing garbage collection problem - if there are a lot of record versions in the TABLE1 which are not interested to any transaction, your query will force garbage collection, and it can take some time. How to check? run SELECT count(*) twice and compare execution times, and other query statistics (reads/writes). Also, run gstat -a -r <database> and check information for TABLE1 - VERSIONS and MAX VERSIONS, if there are big numbers there, problem is certainly related with record versions, with the initial cause in wrong transactions management - i.e., long-running write transactions or forced rollbacks. Regards, Alexey Kovyazin IBSurgeon I'm doing some basic tests with Firebird and I'm facing something I cannot understand (I'm a newbie to Firebird which has worked with IB7.5 for years, so I apologize if I ask something obvious): - I have a linux server with firebird 2.5.4 Superserver: multi-core (4), 3GB RAM - I placed a "huge" database: 1000 tables, 9GB - When I issue a query like this "select count(*) from TABLE1" it takes very long time to complete (>30 min). - TABLE 1 has 3 million records As I told you, I'm quite used to IB7.5, but I guess this is not normal at all...probably I'm missing something but I couldn't find any document which gives me an idea of what I'm doing wrong. With same hardware an IB7.5 same query took 40 sec to complete (first time issued, no cache). Could anyone help? -- -- Planatec Software S.L. ** <http://www.planatec.es> telf: +34 964 340 560 ** fax: +34 961 130 921 -- Planatec Software S.L. ** <http://www.planatec.es> telf: +34 964 340 560 ** fax: +34 961 130 921 -- Planatec Software S.L. ** <http://www.planatec.es> telf: +34 964 340 560 ** fax: +34 961 130 921