0
votes
3answers
257 views

How to determine the optimal sort_buffer_size?

I read from a sample configuration file which says the following: # Sort buffer is used to perform sorts for some ORDER BY and GROUP BY # queries. If sorted data does not fit into the sort buffer, a ...
3
votes
1answer
111 views

Tuning key_reads in MySQL

We are trying to tune our MySQL database (Myisam, 5.1.73) which is getting busy. We investigated Key_reads: $ mysqladmin ext -ri10 | grep Key_reads During a normal load we have the following ...
1
vote
0answers
13 views

MySQL: index statistics dropped when table dropped?

When a table is dropped, are its index statistics also removed? The reason I ask is that I was hoping to 'prep' the stats by running log playback via the percona-playback tool prior to cutting over ...
0
votes
2answers
136 views

mysql need help optimizing query

I have a table containing servers logs, and another table containing rules to match certain and drop them. The logs tables contains around 1 million rows, and there are about 20-30 rules. The ...
0
votes
2answers
808 views

Percona Xtradb Cluster : How to speed up insert?

I recently installed a 3 full master node cluster based on Percona Xtradb (very easy install). But now i need to make some tuning to increase INSERT/UPDATE requests. Actually, i made around 100 ...
0
votes
0answers
110 views

InnoDB tuning with 1G of ram limit

I am trying to calculate variable moving averages crossover with variable dates. That is: I want to prompt the user for 3 values and 1 option. The input is through a web front end so I can build/edit ...
0
votes
0answers
64 views

mysql: how many disk seeks were made for a select query

I will fire a select query. I want to know how many disk seeks does that query take. mysql documentation has given formula for full table scan. ...
1
vote
1answer
1k views

MySQL 5.5 - determining correct write[read]_io_threads on high-end system?

Specifically dual-CPU 32 core - 128RAM - RAID 10 SSD . Ubuntu 64 server. Heavy Innodb load at times - ~ 2000+ queries per sec. Heavy read and write. Currently we are running on the default ...
2
votes
1answer
4k views

MySQL 5.5 - Innodb - innodb_log_file_size higher than 4GB combined?

When reading online about innodb_log_file_size, it says The combined size of the log files must be less than 4GB So what happens if it needs to be larger? In books and online, it says to set ...
0
votes
1answer
3k views

Mysql 5.5: Optimizing all tables with mysqlcheck - is it useful to run the -check option along with -optimize?

I plan on running 'mysqlcheck --optimize --all-databases' to clear up some fragmentation. Would it be useful to run -check with this option or does the -optimize already take care of that? I am only ...
1
vote
1answer
79 views

tuning feed item's table query with multiple condition

I have a query like this: SELECT * FROM `rss_item` WHERE `feed_id` = 1 and `timestamp` < 1350698635 ORDER BY `rss_item`.`timestamp` ASC MySQL: 5.1; table engine: innodb Explain result: ...
2
votes
1answer
2k views

InnoDB Performance Tuning

I'm new to database administration so please excuse any omissions of what would seem like basic info to provide for this problem. I'm a RoR developer and our team is currently short a DBA, so we're ...
2
votes
2answers
2k views

MySQL 5.1.63 - using tuning-primer - Table Cache question

tuning_primer says the following: TABLE CACHE Current table_open_cache = 812 tables Current table_definition_cache = 256 tables You have a total of 498 tables You have 812 open tables. Current ...
6
votes
1answer
1k views

Tuning dedicated Percona Server with XtraDB for OLTP

Hardware specs for an OLTP DB dual quad core xeon with hyperthreading 24GB ram Hardware RAID10 BBU Software specs Standard install of Ubuntu 10.04LTS with default LVM partitioning Installed ...
29
votes
3answers
36k views

Possible to make MySQL use more than one core?

I've been presented with some dedicated MySQL servers that never use more than a single core. I'm more developer then DBA for MySQL so need some help Setup The servers are quite hefty with an ...