I have seen some slight performance degradation above 4 indices. I usually recommend that you have no more than 6, but 5 or even 6 can be ok, in a pinch. So the answer is that you're approaching the point where there will be a measurable negative impact on throughput. The complete answer is test it & see if the performance hit exceeds your tolerance level.
Defining the indices as NO.NULLS helps a lot (I've had folks tell me that they _had_ to index on null values. I'm unconvinced that there's much value in that unless only a tiny percentage of the records will have a null value in the field). With a dynamic file that large, I'd also be looking for ways to minimize split operations. Usually, I'll see a very high percentage of writes doing splits when a dynamic file is that large - and those are expensive writes. You may want to make sure that MINIMUM.MODULUS is not less than CURRENT.MODULUS, and increase it with an ample growth factor. Of course, if you're running in 32 bit mode, you may not have any wiggle room left there, and may want to look into converting this into either 64-bit or a distributed file.> Date: Wed, 12 Sep 2007 11:39:09 -0700> From: [EMAIL PROTECTED]> To: [email protected]> Subject: [U2] Does anyone know the effect of adding an ndex to a UniVerse file?> > Does anyone know the effect of adding an index to a UniVerse file?> > I'd like to add a date index to a type 30 file with 11 million records. (> ANALYZE.FILE Total size ................. 2,115,325,952 bytes)> > Would this have any measurable speed slowdown on applications running> against the file?> > The file currently has 4 other indexes.> > -- Louie Bergsagel> Seattle> -------> u2-users mailing list> [email protected]> To unsubscribe please visit http://listserver.u2ug.org/ _________________________________________________________________ Can you find the hidden words? Take a break and play Seekadoo! http://club.live.com/seekadoo.aspx?icid=seek_wlmailtextlink ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
