Re: Raw partitions / cooked files

>From: uunet!mentat.mel.cocam.oz.au!shaneb (Shane Booth) >Subject: Raw partitions / cooked files >Date: 8 Jul 93 03:19:30 GMT >X-Informix-List-Id: <news.3758> >We have OnLine databases (version 5.0) on a Sun SPARCstation 10, one on a >raw partition and one on a cooked file. >For a query involving a join on two tables, where one of the tables is very >small (~10 rows) and we do a sequential scan through the second table >(~40Mb and ~50000 rows), the raw partition takes 2.6 times as long (on >average) as the cooked file to execute the query. I just can't work out why? >It's supposed to be the other way 'round isn't it? >Details: SPARCstation10 Model 30, OnLine version 5.00.UC3. Yes, the raw device should be faster than the cooked one. That was easy. Now, why aren't you finding that it is? We're going to need to know a good deal more about your hard disk configuration and other aspects of your system. How many physical drives have you got? How are they partitioned? Where is the raw device space, the cooked space, the root file system, the tmp file system, the swap space? How much shared memory (buffers) have you configured? How big is your kernel buffer pool? Have you run update statistics? Would it make any difference? How much other activity is there on the machine? Without most of this information, anybody trying to answer your question will be hunting in the dark. Now, where's my nightsight? Yours, Jonathan Leffler (johnl@obelix.informix.com) #include <disclaimer.h>