Monthly Archives: July 2008

Quick note on bulk performance using on duplicate key update

Had an interesting thought today, I wonder how much faster ( if at all ) updating via insert on duplicate key in bulk was compared to individual update statements.  The client  app I was looking at receives updates to a … Continue reading

Posted in mysql, performance | 1 Comment

MySQL, Innodb, DBT2 Core Scalability Graphs

I was at a client site with Yves Trudeau ( another MySQL consultant ) and the client had purchased a brand new top of the line 16 core server.  It is well documented in many places that scalability beyond 4-8 … Continue reading

Posted in linux, mysql, performance | 5 Comments

Single Quotes and integers

While looking at the performance of multiple datafiles I noticed something kind of interesting.  A query searching for a integer based PK value that had the value escaped with single quotes was faster then another lookup on a PK without … Continue reading

Posted in mysql, performance | 1 Comment

Single Innodb Datafile vs Multiple datafiles

Over the past couple of months I have seen a few different clients with innodb setup to have multiple datafiles opposed to using file per table or a single datafile. While I generally do not think twice about a handful … Continue reading

Posted in Common Mistakes, mysql, performance | 3 Comments

Dell/LSI Mega raid CLI command cheatsheet

Wanted to remember these for later: DELL PERC 6i & LSI RAID CHEAT SHEET: To add a RAID 10: ./MegaCli64 -CfgSpanAdd -R10 -Array0[17:0,17:1] -Array1[17:2,17:3] -Array2[17:4,17:5] -Array3[17:6,17:7] -Array4[17:8,17:9] WB NORA  -strpsz64 -a0 (WB is write back, WT is write through) (NORA … Continue reading

Posted in hardware, linux, raid | 1 Comment