Did you know, how to accelerate your large querys with a new feature?
Henri Cujass announced that setting DIRECT_IO 0x5 enables direct I/O for normal and TEMP dbspaces, claiming up to 3x faster large queries. He said it appeared in 12.10.xC13 and 14.10.xC3, per onconfig.std comments. Art Kagel asked for documentation updates; Paul Watson said it is in 14.10.FC2 but undocumented. David Williams asked if anyone had tested it; no answer.
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Hi Informix scentists, I have the feeling, that most of you didn't notice a new performance feature I introduce with Informix R&D last year. If you like to push up your batch or DS querys, try to set "DIRECT_IO 0x5" . This will enabling the direct i/o for the normal DBSpaces AND the TEMP DBSpaces. It's not that easy to see, that the TEMP DBSpaces didn't work with direct i/o by default - that's the reason we introduce this feature and accelerated large querys and report batches up to 3 times ! Thank you very much to Holger K. from the Informix team for support on this new feature. Hi Informix admins: Set the DIRECT_IO parameter in your onconfig file to 0x5 and accelerate your large queries, if available. Have fun on this, Henri Cujass, your friend from leolo IT ------------------------------ Henri Cujass leolo IT, CTO Germany ------------------------------ #Informix
Very cool Henri. Can we get the online documentation updated? Also the New Features pages so we know what versions support this? Art Art S. Kagel, President and Principal Consultant ASK Database Management www.askdbmgt.com Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves.
Hi Art, I think this feature was released for 12.10.xc13 and 14.10.xc3 . You can get the information from the inline comments in the onconfig.std file: # DIRECT_IO - Set of flags that may be combined to control "special" I/O # 0x0 = Neither direct I/O nor concurrent I/O is used # 0x1 = Direct I/O is used if available # 0x2 = Concurrent I/O is enabled (on AIX operating systems) # 0x4 = Special I/O is enabled for TEMP DBspaces I remember, that a student shows me in the online documentation - but maybe it's in developerworld and not in the official Informix online documentation. I had the feeling, that nobody noticed this new hidden feature. Best Regards Henri ------------------------------ Henri Cujass leolo IT, CTO Germany ------------------------------
Henri: Yup. Hoping someone at HCL will see the thread and update the docs. While I'm asking for improvements to the documentation, I'd still like an update to the PDF documentation which has not been updated since 12.10.FC8! Art Art S. Kagel, President and Principal Consultant ASK Database Management www.askdbmgt.com Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves.
A doc request update was made a while back Cheers Paul
It is in 14.10.FC2 although undoc'd. Cheers Paul
I've been making requests for four years now. Art Art S. Kagel, President and Principal Consultant ASK Database Management www.askdbmgt.com Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves.
I saw this (in an IIUG presentation?), has anyone done real world testing with this feature? Regards, David. ------------------------------ David Williams ------------------------------