MySQL Performance: MySQL => MySQL memory usage planning

MySQL memory usage planning [message #250]

Wed, 11 October 2006 09:47

ugob
Messages: 2
Registered: October 2006

Junior Member

Hi,

I'd like to determine if adding memory to our server may help performance. Our system is basically using two databases. On the first one, there are 2 big tables. The database is 4.4GB big (3.1 data, 1.3 indexes). This database serves mainly for maillog entries. Inserts are ok, but we are looking for a way to increase the speed of report generation (which uses SELECT queries). Everytime we try to generate a report, the cpu falls almost 100% iowait. I guess that means that the CPU is waiting for disk I/O.

There is also one database (about 1.3 Gb 600MB data/700MB index) wich is our Bayes database for spamassassin.

The server has 4 GB of RAM and is running the MySQL server and is also scanning e-mails (wich uses about 800MB of RAM). Server is dual Xeon 3.0Ghz, 2 MB cache, SCSI disks, RAID 1 Megaraid.

We were wondering if increasing the physical memory in this server would increase the performance in report generation. Since the bottleneck is the hard drives, if I put more memory in the server, it may be possible for mysql to put all the table in memory and work on it from there. Am I right?

Regards,

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