database error help

[Sycoloco1212]

need help i ran this

Admin CP - Maintenance - Rebuild Search Index

i pushed "Note: If you are re-indexing, you may want to empty the indexes. Click Here to do so!"

and pushed rebuild search index

i thought this would redo like the meta key words ect.. and index pages for google? if im correct.. and im getting this database error in my email

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
/home/hacke5/public_html/forums/includes/class_core.php on line 311

MySQL Error :
Error Number :
Request Date : Sunday, August 31st 2008 @ 04:21:07 AM
Error Date : Sunday, August 31st 2008 @ 04:21:07 AM
Script : http://mpgamerz.net/forums/showthread.php?t=807
Referrer : http://mpgamerz.net/forums/forumdisplay.php?f=205
IP Address : ***.***.***.***
Username :
Classname : vb_database
MySQL Version :

--------------- Added 1220181958 at 1220181958 ---------------

nevermind delete this post my forum came back online, whats this do exactly though?

[Opserty]

<a href="http://www.vbulletin.com/docs/html/cantconnect" target="_blank">Can't connect to local MySQL server through socket</a>