Best way to do mass delete of records MSsql server 2005 coldfusion
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.
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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>
>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.
Then DELETE is your only option, as only DELETE supports a WHERE clause where you can delete a subset of rows.
ASKER
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
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
ASKER
no schedule outage - but could put message in application.cfm that database is being maintained
ASKER
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?
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?
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
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
ASKER
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
in SQL Server Management Studio, right click the database and choose to Shrink File and you can shrink the database file down.
ASKER
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
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.