Collecting Statistics on Global Temporary Tables

Database

Collecting Statistics on Global Temporary Tables

Hi,

Can anyone help me on this question??... For GTT Tables while defining stats which one of the below Query works better?

 1.

collect stats on tablename column ColumnNM/Index

OR

2.

Collect stats on temporary tablename column ColumnNM/Index

After defining the stats using 1st query and  loading the data, I checked the table with HELPSTATS command.... but I couldn't see any stats!

So I used the 2nd query and checked.Then I saw the stats for the tables.

My question is : When I am using the index columns or some key columns in some join conditions from this GTT for loading data into another table how should I define stats for this GTT as stats helps in performance improvement. Does both the query work fine ? or the 2nd query is better?

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2 REPLIES
Teradata Employee

Re: Collecting Statistics on Global Temporary Tables

The second form (with TEMPORARY keyword) collects statistics on your session's materialized instance of the GTT.

For a GTT, the first form only defines (dummy) statistics on the base definition of the GTT. Those stats definitions are inherited when a new instance is materialized; you can then use "re-collect" syntax with the TEMPORARY keyword to collect the actual stats:

COLLECT STATS ON TEMPORARY tablename;

Re: Collecting Statistics on Global Temporary Tables

Thanks! Fred.