Re: Parallel index building

Thomas Mieslinger wrote: > > Hi *, > > I have a large table fragmented in three dbspaces on three disks. When I > do an create unique index then the iostat tells me the DBMS is reading > just from one disk not from three. > > I'm using Solaris 2.6, IDS 7.31UC2 and the following DSS Settings: > MAX_PDQPRIORITY 100 > DS_MAX_QUERIES 64 > DS_MAX_SCANS 64 > DS_TOTAL_MEMORY 256000> > The system is an 4 way PIII 500 Acer Altos with 512MB RAM. > > So how can I speed up the index building? Can it be done parallel? The key, as the other Thomas pointed out, is that you must set PDQPRIORITY. Setting MAX_PDQPRIORITY just sets the maximum. It does not switch on PDQ. As Art stated, you can gain a significant performance boost by setting PSORT_NPROCS. I know Art always claims using file system space (PSORT_DBTEMP) is faster than dbspaces, but then he probably has about 18 spindles behind each file system. :-) So I would expect dbspaces (DBSPACETEMP) to be quicker on a system that uses no RAID configuration. Cheers, -- Mark. +----------------------------------------------------------+-----------+ | Mark D. Stock http://www.informix.com |//////// /| | mailto:mdstock@mydas.freeserve.co.uk |///// / //| | http://www.iiug.org +-----------------------------------+//// / ///| | |What year 2000 bug? year 2000 bug? |/// / ////| | |year 2000 bug? year 2000 bug? year |// / /////| | |2000 bug? year 2000 bug? year 1900 |/ ////////| +----------------------+-----------------------------------+-----------+