Reduce size of database file

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Reduce size of database file

Saqib-215297

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Points: 147
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December 27, 2007 at 5:55 am

#122773

hi all,
I am using SQL server 2000. My databse file MyDB_DATA.MDF grew up to 60161 MB.
please suggest me should I reduce the size of the file, and how it can be.
I have about 2,00,00,000 records in a table which are being queried.
More over I have 2 more tables of same specs mentioned above.
Queries are taking lot of time. usually more then 30 minutes to execute.
please suggest me, what stuff should be considered for an efficient query.
I am not joining the tables rather quering them sepately.
Should I keep only one table ? Do the above situation creates a lot of burden on SQL server?
do the efficiency increases by removing extra tables?
any help ??

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AlexSQLForums SSChampion Points: 14277 More actions · Answer 1

Run this script to find out how much free space you have in your database.

-----------------------------------------------------------------

Set Nocount On

Create Table ##filestats (

DbName varchar(100) NULL,

FileID int NULL,

FileGroupID int NULL,

FileTotalSizeMB dec(19,4) NULL,

FileUsedSpaceMB dec(19,4) NULL,

FileFreeSpaceMB dec(19,4) NULL,

FileLogicalName varchar(100) NULL,

FilePath varchar(100) NULL

)

Exec sp_MSForeachDB

--@command1 = 'Use ?; DBCC UPDATEUSAGE(0)',

@command1 = 'Use ?;Insert ##filestats (FileID, FileGroupID, FileTotalSizeMB, FileUsedSpaceMB, FileLogicalName, FilePath) exec (''DBCC SHOWFILESTATS WITH NO_INFOMSGS ''); update ##filestats set dbname = ''?'' where dbname is null'

-- remove any db's that we don't care about monitoring

Delete From ##filestats where charindex(dbname, 'master-model-pubs-northwind-distribution-msdb') > 0

Update ##filestats set FileTotalSizeMB = Round(FileTotalSizeMB*64/1024,2), FileUsedSpaceMB = Round(FileUsedSpaceMB*64/1024,2)

where FileFreeSpaceMB is null

Update ##filestats set FileFreeSpaceMB = FileTotalSizeMB - FileUsedSpaceMB

where FileFreeSpaceMB is null

Select dbname, fileusedspacemb, filefreespacemb from ##filestats

Drop table ##filestats

Set Nocount Off

-----------------------------------------------------------------

fileusedspacemb and filefreespacemb will show you how much space your database is actually using and how much space there is free.

you can then run

DBCC SHRINKFILE (N'MyDB_DATA.MDF' , 0, TRUNCATEONLY) - -this will free up filefreespacemb

or

DBCC SHRINKFILE (N'MyDB_DATA.MDF' , 'number of MB you want to shrink it to')

you should create indexes on the columns that you use in your where clause.

Alex S

Steve Jones - SSC Editor SSC Guru Points: 736504 More actions · Answer 2

Extra data can have an impact, but only in the data cache. SQL can easily handle 60GB of data in a few tables.

Are your tables indexed? They should be indexed on columns used in WHERE clauses as well as join conditions.

If you need the data, then it should stay. If you have extra copies to speed things up, that doesn't help.

colin.Leversuch-Roberts SSC Guru Points: 52643 More actions · Answer 3

shrinking a mdf file can have serious detrimental effects on your database, if you must shrink the file you should rebuild all your indexes afterwards to get the best chance of contiguous data storage and minimise mixed extents.

[font="Comic Sans MS"]The GrumpyOldDBA[/font]
www.grumpyolddba.co.uk
http://sqlblogcasts.com/blogs/grumpyolddba/

rlvantrease SSC Enthusiast Points: 113 More actions · Answer 4

I agree with SSCommitted. I wouldn't just shrink your DB just because it is large. I also agree with Steve. 60 GB isn't beyond SQL Server's capabilities by any means.

If there is a large amount of unused space in your DB, you should probably look at why. If it grew to 60 GB but now has a large amount of free space chances are good that if you shrink it it will simply grow again. The shrinking and growing will bog down your server if it is done continuously.

You mentioned a couple things that made me think you might have design issues. First you mentioned that you have one really large table and two more tables with the same specs. Second you asked if you should "keep only one table".

It sounds like your database design might not be normalized very well. If you post your table structures, indexes and a brief description of what you are doing with both as well as a sample query that is taking 30 minutes you might be able to get some good suggestions here.

Jeff Moden SSC Guru Points: 1004414 More actions · Answer 5

have about 2,00,00,000 records in a table which are being queried.
More over I have 2 more tables of same specs mentioned above.
Queries are taking lot of time. usually more then 30 minutes to execute.
please suggest me, what stuff should be considered for an efficient query.
I am not joining the tables rather quering them sepately.

Without knowing the table schema, what the indexes are, how often you maintain them, what the code is, and what the actual data looks like, the simple answer would be that you need to get better at all of that... particullarly where the code and the indexes come into play.

If you want help, please help us help you... do read the following if you actually want an answer that helps...

http://www.sqlservercentral.com/articles/Best+Practices/61537/

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

Ian McQuade SSC-Addicted Points: 464 More actions · Answer 6

Hello,

Depending on the data kept you may want to divide it up amongst other tables if possible

Your queries may be iterating through chunks of data you dont really care about.

Have you looked at execution plans of you scripts to see what they are doing? This should really help you out.

Try using Profiler and the Tuning Wizard to give you some help also

Thanks

Ian