Operations Manager: MOM 2005

MOM 2005 Reporting - Grooming and Shrinking the Reporting database

Sat, 24 Mar 2007 17:45:04 GMT

How to Groom and Shrink a Reporting database

We had a MOM 2005 reporting database which had not been archiving correctly and had grown to the point that there wasn’t enough free disk space to run the grooming process, due to increases in the size of the log files. Based on business requirements and hardware constraints the decision was made to trim down the content of the reporting database down to 35 days from what was originally data that was more than 500 days old. The original database size was approximately 55 GB with no free space, after successful grooming it was moved down to .5 GB (prior to re-activating the DTS package to transfer from the Operations database to the reporting database).

To accomplish this, we took the following high level process (all scripts referred to are included in full below):

Identify the count of each of the 6 fact tables using the "Table Count" script, and keep track of those statistics going forward.

Identify the oldest data in the tables using the "Oldest Date" script.

Determine the date difference between the oldest date and the current date with the "Date Diff" script.

Set the grooming interval to higher than the highest date using the "Set Grooming" script. This is done to ensure the grooming process will work as long as there is no data that needs to be groomed.

Verify the change tot he grooming settings with the "Check Grooming" script.

Start the reporting grooming job (called SCDWGroomJob) in the SQL Agent jobs section of the SQL 2000 Enterprise Manager.

When the job (hopefully!) succeeds, run the "Truncate Log" script to free up some of the transaction log space.

Change the grooming setting to slightly less than the highest difference so that the next grooming job will be configured to actually groom out data.

Re-run steps 5 though 8 for the new setting.

Continue this process with decreasing values (the oldest data in the database we were working through was 508 days!). For that particular environment we were grooming settings which decreased from: 700, 500, 400, 350, 275, 200, 125, 35.

Finally we were able to decrease the size of the reporting database through the "Shrinkfile" script.

Last, w reactivated the scheduled task to move data from the Operations database to the Reporting database and started growing the data again; but this time up to a maximum of 35 days.

Fact Table Statistics: 700 Days 400 Days 350 Days 275 Days

AlertFact 715 715 715 715

AlertHistoryFact 32,184 27,919 21,481 15,748

AlertToEventFact 38,969 34,123 27,609 21,151

EventFact 4,415,065 4,291,870 4,079,922 3,862,984

EventParameterFact 828,708 828,708 828,708 828,708

SampledNumericDataFact 152,648,971 138,060,142 121,863,087 98,431,535

Fact Table Statistics: 200 Days 125 Days 35 Days

AlertFact 715 715 26

AlertHistoryFact 9,234 3,051 1

AlertToEventFact 17,230 8,467 5

EventFact 3,752,214 3,022,275 3,625

EventParameterFact 828,708 828,708 3,315

SampledNumericDataFact 87,401,639 47,819,874 413,745

Scripts

Check Grooming

This script checks the current state of the grooming settings.

SELECT cs.cs_tablename 'Table Name', wcs.wcs_groomdays 'Groom Days' from warehouseclassschema wcs

Join classschemas cs

On cs.cs_classID = wcs.wcs_classID

Where cs.cs_tablename = 'SC_AlertFact_Table'