Solved

Best way to do mass delete of records MSsql server 2005 coldfusion

Posted on 2014-10-01
11
207 Views
Last Modified: 2014-10-01
I want to migrate a database but reduce it first it is 10.5GB  I have a lot of old statistics  records that will reduce this right down. The database is online with customers, CF9. I ran a query from a template but it seems to bring down cold fusion. I have millions of rows to delete. What is the best way?  Thanks. I am not a system engineer - more of a novice in this area.
0
Comment
Question by:Ian White
  • 6
  • 3
  • 2
11 Comments
 
LVL 39

Accepted Solution

by:
gdemaria earned 500 total points
ID: 40355671
If you want to empty a table completely, you can enter  
> truncate table BigTableName

That will remove all records.
0
 
LVL 65

Expert Comment

by:Jim Horn
ID: 40355677
Truncate is correct, assuming there's not an identity column that would cause problems if it was re-seeded back to the start (usually 1).

so I'll throw in some other stuff:
*  Do you have this data backed up somewhere, in case you need to un-delete it?
*  Do you have a scheduled outage where you can delete without having to worry about users being in the app mid-deletion?
*  Anything else needs to happen with this delete, such as delete related tables?  If yes, a TRANSACTION is an excellent idea.
0
 

Author Comment

by:Ian White
ID: 40355683
No dont want to empty completely


<CFMODULE TEMPLATE="getdatasource.cfm">
<CFMODULE TEMPLATE='getnewdate.cfm' Days=360>

    <cfquery name="Delete_Old_VisitorStatistics"
				datasource="housecare2" 
				dbtype="ODBC" >
  DELETE FROM VisitorStatistics
    		
    	WHERE
  		VisitorStatistics.VisitDate  < #NewDate# 
	
  </cfquery>

Open in new window

0
Complete VMware vSphere® ESX(i) & Hyper-V Backup

Capture your entire system, including the host, with patented disk imaging integrated with VMware VADP / Microsoft VSS and RCT. RTOs is as low as 15 seconds with Acronis Active Restore™. You can enjoy unlimited P2V/V2V migrations from any source (even from a different hypervisor)

 
LVL 65

Expert Comment

by:Jim Horn
ID: 40355689
>No dont want to empty completely
Then DELETE is your only option, as only DELETE supports a WHERE clause where you can delete a subset of rows.
0
 

Author Comment

by:Ian White
ID: 40355691
NO related tables
Yes database backed up nightly
non critical table - rarely accessed by users online
It is written to and records visitors to the site looking at members records
0
 

Author Comment

by:Ian White
ID: 40355698
no schedule outage - but could put message in application.cfm that database is being maintained
0
 

Author Comment

by:Ian White
ID: 40355704
I could bit the bullet and empty the statistics table - it will rebuild

I have another large table notifications that is more critical that will need the where

How long would the truncate take?

I do this in the sql studio? what would be the code to truncate?
0
 
LVL 39

Expert Comment

by:gdemaria
ID: 40355706
Before attempting the delete, you can add an index to the column in the where clause to try and speed it up

VisitDate  

Alternatively, you could come up with a strategy to move date that you want to keep into a warehouse or archive tables (perhaps in a different database with simple backup strategy).   Once desired records are copied off (using insert from select) then you can truncate the table.   I do this on a weekly basis to keep high er level stats where the details are no longer important
0
 

Author Comment

by:Ian White
ID: 40355708
After the records are gone - does the db auto be a smaller size for the backup? - or does something have to be done - the backup is 10.5 gb - took big to restore zip then ftp. Currently take hours to restore from the nightly backup by the current host
0
 
LVL 39

Expert Comment

by:gdemaria
ID: 40355737
in SQL Server Management Studio, right click the database and choose to Shrink File and you can shrink the database file down.
0
 

Author Closing Comment

by:Ian White
ID: 40355969
Thanks that was easy in studio , now just need to check with hosting engineers how to shrink without impacting users - does not appear to be much free space
0

Featured Post

Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Sometimes databases have MILLIONS of records and we need a way to quickly query that table to return the results me need. Sure you could use CFQUERY but it takes too long when there are millions of records. That is why SOLR was invented. Please …
This article explains how to reset the password of the sa account on a Microsoft SQL Server.  The steps in this article work in SQL 2005, 2008, 2008 R2, 2012, 2014 and 2016.
This Micro Tutorial hows how you can integrate  Mac OSX to a Windows Active Directory Domain. Apple has made it easy to allow users to bind their macs to a windows domain with relative ease. The following video show how to bind OSX Mavericks to …
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

773 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question