Alexey Kovyazin wrote:

I am a bit tired of repeated topics regarding database performance, so I decided to publish short version of our performance questionnaire

I suggest to always ask people who come here with Firebird performance problems to answer these questions and send answers to the list, in order to facilitate performance problems resolution.


  • CPU Model and number of cores
  • RAM amount
  • HDDs
  • Model of HDDs (SAS, SATA, SSD) and their parameters (size, cache size, rpm) or exact HDD model
  • Is there RAID?
  • If yes, what is RAID Controller (model)? If it’s software RAID, model of motherboard
  • How many drives and RAID type (0,1,5,6,10, etc)?
  • Is Battery Backup Unit installed in RAID(if needed)?
  • What is RAID cache mode (Write Through, WriteBack)? What is the size of the stripe set?
  • How system is located at HDDs: where is System location, where is database, where are temp files (if changed)? What is the block/cluster size of the partition with the databases?
  • Any specific details about hardware you can provide (like vendor, model of the server, etc)


  • Is OS running as Virtual Machine instance? If so, what kind of VM (ie: VMWare, VirtualBox, etc), and what are parameters of this instance (# of CPU cores, RAM, HDDs).
  • How many other Virtual Machines are running at the same host with Firebird server?

Operation System

For Windows

  • What is Windows version, is it 32 or 64 bits and service packs installed (like Windows 7 Pro 32 bit, Windows Server 2008 R2 64 bit, Windows 8 64 bit, etc)
  • If it is a Windows server, is it domain controller?

For Linux

  • What is the version of Linux? 32/64 bit?
  • What is Linux kernel version and glibc?


  • What is the exact Firebird version (on Windows you can right-click on Firebird executable, tab Version or Details, on both Windows and Linux run isql -z)?
  • What is Firebird architecture – Embedded, SuperServer, Classic or Super Server (check what is running - fbserver.exe is for SuperServer, multiple fb_inet_server is for Classic, single fb_inet_server - SuperClassic)?
  • Where is Firebird installation folder?
  • Please send firebird.conf
  • Please firebird.log (zipped)
  • Please run fb_lock_print –d 3 times during peak time (for example, 11-00, 14-00 and 16-00), zip results and send to us.


  • What is the database size?
  • How many databases are on the same server?
  • Please post here output of gstat –h from the peak load (around noon), and no load – early morning or late evening.
  • Please get output from peak time with this command gstat –a –r > stat.txt and send it to us (zipped).


  • Is it client/server (when each user runs separate instance of application “per connection”, and usually each user runs on the separate computer) or middleware (when there is the single instance (or a few instances) which works in multi-tier mode, for example, Java web-application in Apache/Tomcat)?
  • Is it 32 or 64 bit?
  • What is the platform (Windows, Linux, MacOS X)?
  • How many client connections do you have during normal load and at peak times? (if you are using FB 2.1 or greater, run SELECT count(*) from MON$ATTACHMENTS )
  • What data access method are you using (ex: JDBC, ODBC, etc… for Delphi apps: BDE, IBX, IBO, dbExpress, etc. )
  • What is the type of the application? For example – CRM, ERP, accounting, etc?

Describe the performance problem

  • Background of the problem
  • Were there changes recently in hardware/OS/applications?
  • Is there random peaks, or problems occur during specific moments (for example, after lunch, around 16-00, etc)?
  • Any other details about the problem (What users say about a problem?)

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