Showing posts with label mysql tmp tables solaris dtrace. Show all posts
Showing posts with label mysql tmp tables solaris dtrace. Show all posts

Wednesday, April 14, 2010

Which sql query you think is the worst for disks ...

Based on milek.blogspot.com

#!/usr/sbin/dtrace -qs

#pragma D option strsize=8192


pid$3::*mysql_parse*:entry
{
self->a=1;
self->query=copyinstr(arg1);
self->count=0;

}

pid$3::*mysql_parse*:return
/ self->a && self->count > $2 /
{
printf(\"### write() count: %d ###\\n%s\\n\\n\", self->count, self->query);

self->a=0;
self->query=0;

}

pid$3::*mysql_parse*:return
/ self->a /
{
self->a=0;
self->query=0;
}

syscall::*write*:entry
/ self->a /
{
self->count++;
}

tick-$1
{
exit(0);
}