Secondary Index Usage

Database

Secondary Index Usage

I am currently examing table definitions for usage of the secondary indexes and have come across what I take as conflicting information.

 

In the first source, I'm looking at the DBC.Indices view. The view tells me that one of the secondary indexes (Group_Key) in the LastAccessTimeStamp column says that the index was last accessed on 1/27/2017 17:52:12. 

 

In the second source, I'm looking at the DBQLObjTbl. The most recent CollectTimeStamp here says that the Group_Key secondary index was used on 2/3/2017 12:40:28. 

 

My question is why am I seeing these two different dates?  Does the information in these two columns mean different things?

5 REPLIES
Teradata Employee

Re: Secondary Index Usage

What version of TD? LastAccessTimeStamp is maintained through UseCount logging, which is a separate option from Objects.

Enthusiast

Re: Secondary Index Usage

Interesting. I was under the believe that Object Use Count (OUC) would only track tables/views.

Re: Secondary Index Usage

Fred,

 

We are running TD 14.10

Teradata Employee

Re: Secondary Index Usage

Then ObjectUseCount logging is a system-wide dbscontrol setting rather than DBQL. But still an entirely separate option.

 

Re: Secondary Index Usage

Fred,

 

Thanks for the clarification on the difference.