[R] loading data and executing queries with R and Mysql

bogdan romocea
Wed, 03 Jan 2007 13:30:01 -0000

Nevermind the CPU usage, the likely problem is that your queries are
inefficient in one or more ways (i.e., you don't use indexes when you
really should - it's impossible to guess without knowing how the data
and the queries look like, which somehow you've decided are not
important enough to describe in your email). One nice reference is
http://highperformancemysql.com/


> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Bagatti Davide
> Sent: Wednesday, January 03, 2007 8:05 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] loading data and executing queries with R and Mysql
>
> Hello everyone,
>
> I have a problem when I execute queries using R 2.3.1 and
> MySql server 5.0.
> What I do: I load data in different csv files (every file represents a
> particular temporal step of a simulation) using Mysql query
> "load data" with
> RMySQL command DbSendQuery (but the same problem there is also using
> DbWritetable). Then I use a function where I have a lot of
> queries that
> interact with the database.
> Well, while loading data is very fast, query execution is very slow
> ...looking to Windows task manager I see that my cpu doesn't
> go to 100% of
> usage, but only at 30-45%. Looking at the processes I see Rgui.exe use
> between 0-23% and mysql-nt.exe use between 8-20% and so it is
> very slow. I
> am sure my cpu has no particular problems.
> Could you help me?
>
> Thanks in advance
>
> Davide
>
> 	[[alternative HTML version deleted]]
>
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