What does the procedure do? Can you post code?

May I suggest you post mySQL questions on a mySQL site (like http://forums.mysql.com/). This site is specifically for Microsoft SQL Server.

What exactly is wrong with updating a column to NULL?

The Nolock hint will be ignored since it's on the target table for an update (that should be documented in...

Before you go the filegroup route.... The DB needs to be in full recovery and you need log backups covering the range from the oldest read-write filegroup backup to the...

Do you have a clean backup of the MSDB database?

Well.... those are interesting choices of counters. Do you know how (or how not) to...

The answer to both of those is 'test it'

Read committed snapshot can be very useful, you have to test and make sure that the overhead on TempDB isn't too bad....

Views can't have primary keys.

We're not here to do your job for you. If you're going to miss a deadline, tell your manager beforehand that you're behind. If you don't know T-SQL, then make...

I suspect not that much can be done while all those REPLACE and TRIM functions are needed in the WHERE clause. Is the data really that messy?

How? Top without an order by I can see, MIN (the minimum value) should...

Duplicate thread, please stick to a single thread per question: http://www.sqlservercentral.com/Forums/Topic1586319-391-1.aspx

The total memory should be fine, but to be sure rather use Perfmon. Available MB for free memory, SQL's Total Server Memory for what it's using

The optimiser estimated that the operator in question would execute 200 times during the course of the query's execution. It's an estimation.

Don't use Task Manager to check SQL Server's memory usage, it can show incorrect values.