Tivoli Data Warehouse - Summarization And Pruning considerations

We' ve covered quite a bit on the Tivoli Data Warehouse (TDW) and what happens when you initialize history collection for a given table. 

Once you have had history collecting for an interval of time, you may want to look at using summarization and pruning to control the quantity of data being retained, and to also take advantage of the ability to use summarized data for trending purposes. 

Below is an example of the configuration options for summarization and pruning.  As part of the earlier exercise we enabled TDW history collection for Common Storage.  Now we are going to enable summarization and pruning for this data. 

In the above example, we are enabling pruning on detailed data by specifying that we will keep 30 days of detail.  Detail beyond that point will be removed by the Summarization and pruning agent process.   Also, the detail data will be summarized, both on an hourly and on a daily basis.  We will be keeping 90 days of hourly data, and one year of daily data. 

By specifying summarization and pruning, we can control the quantity of data being retained within the TDW.  This can be very important, especially for high volume tables of data or tables being collected for a large number of managed systems. 

Another consideration to be aware of is that when you specify summarization, the summarization agent will create another set of tables.  In the above example, the agent will have DB2 to create a table for hourly data and another table to hold daily data. 

This is an area of confusion for some uers. I have encountered some shops who thought they were going to save space right away by turning on summarization.  However, when they enabled the function, the TDW database ended up requiring more space.  Why?  Because the summarization agent had to create the additional tables to store the summarized data.