Re: SMP & threads for SQL queries

Your question asked about Intel SMP, threads, linux, support for large memory configurations, and queries against a database with minimal updates.

It would be helpful if you gave some information on your priorities. Is it cost, performance, stability, support? But if you're talking about 512MB of RAM, I'll assume it isn't cost.

It's hard to generalize, but large databases are usually I/O bound, not CPU bound. A huge hardware performance boost can come from using RAID disk arrays with Raid Level 0 (no redundancy, just striping). This will speed up read access times according to the number of disks in the array. Most of the major PC vendors support this. If you're serious about performance, and depending on the size of your data, you can have e.g. 18 2GB disk spindles running with three disk controllers, which will give you 36GB capacity, but each file will be striped across 18 spindles, giving an almost 18X improvement in throughput. Such RAID arrays are used in TPC-C PC benchmarks published by the hardware vendors.

I can't comment on Linux, but I've seen Sybase on NT running with 1GB RAM. Current releases of OS/2 have a 512MB limit on RAM, but the upcoming Warp Server SMP for OS/2 (going GA 9/30/96) increases the maximum significantly (don't remember the new limit offhand).

Regarding threads for queries, the multi-platform implementation of Sybase provides a consistent thread model within the Sybase kernel, that is independent of the platform's thread model.

System 11's unique Logical Memory Manager provides great flexibility in tuning large memory configurations to the exact needs of your application and queries, illustrated by its leading TPC-C numbers on many platforms, including Unixware.

Add System 11 to the current low cost of disk and memory, RAID striping, Pentium Pro SMP, and a stable and supported operating system, and you've got unprecedented processing capacity in an affordable workgroup-class system.

Rich Persaud
OS/2 Server Porting
Sybase, Inc.

Linas Vepstas (linas_at_fc.net) wrote:
: Hi,
 

: Can anyone recommend an sql server that supports SMP
: (symmetric multiprocessing) & threads for queries?
 

: We are looking at buying a 2-way or 4-way pentium pro,
: and running linux on this. It seems that the popular
: (i.e. cheap) linux databases (msql, justlogic, empress)
: may not support this. clearly, its a waste to buy an
: MP system if the databases won't make use of the extra
: processors. The database would be mostly queried, and
: very, very rarely updated.
 

: Anyone with experiences, please report ...
 

: Also, what is the largest database anyone has run
: under linux? More than a few gigs? What's the largest
: amount of real memory anyone has used? Has anyone
: attempted to plug in 512 meg of simms, or more into
: a linux box?
 

: --linas
: linas_at_fc.net
Received on Sat Sep 14 1996 - 00:00:00 CEST