AUTOTEMP and BLC

Database
Enthusiast

AUTOTEMP and BLC

Hi Community,

 

We are trying to implement AUTOTEMP on a few tables as the next step in compression.  When loading to an empty, AUTOTEMP-defined table, how is the data compressed?  Or is it not expected to be compressed on the initial load?

Is there a QUERY BAND setting that can be used to ensure compression on the initial load?

 

TVSTEMPERATURE doesn't seem to help.

2 REPLIES
Senior Apprentice

Re: AUTOTEMP and BLC

Hi,

 

"how is the data compressed? " - this is done using the block compression algorithm (the feature that you're using is also known as 'temperature based block level compression'). Which brings me on to:

 

Have you tried the BLOCKCOMPRESSION query band?

 

HTH

Dave

Ward Analytics Ltd - information in motion
www: http://www.ward-analytics.com
Enthusiast

Re: AUTOTEMP and BLC

Hi Dave,

 

Thanks for the reply.

Yes, we have enabled BLC in our environment and enabled all features (via dbscontrol) to promote temperature-based compression.  The new table was defined with the BLOCKCOMPRESSION=AUTOTEMP option and  SET QUERY_BAND = 'BLOCKCOMPRESSION=YES': FOR SESSION;  was executed immediately before the INSERT/SELECT.

 

I also tried SET QUERY_BAND = 'TVSTEMPERATURE=COLD;' FOR SESSION

 

The data is loaded fully uncompressed.