Update completed . No rows changed

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1 .The below collect stats statment on volatile table in Teradata Bteq script returns no rows changed . Can some one help me to understand whether the stats are collected or not ?.

collect stats on ORDER_VT column (ORDER_ID);

** Update completed. No rows changed. *** Total elapsed time was 16 seconds.

2.Trying to collect the stats on below volatile created in two different ways .

  • Collect stats on all columns at a time
  • Collecting stats on each column individually Whats make the the difference here .

Create multiset volatile table TEST1 as ( select COLMN1, COLMN2, COLMN3, from TABLE1 T1 inner join TABLE2 T2 on T1.KEY1=T2.KEY1 AND T1.KEY2=T2.KEY2 )WITH DATA PRIMARY INDEX(COLMN1,COLMN2,COLMN3) ON COMMIT PRESERVE ROWS;

Collect stats on TEST1 column(COLMN1,COLMN2,COLMN3);
Collect stats on TEST1 column(COLMN1 );
Collect stats on TEST1 column(COLMN2 );
Collect stats on TEST1 column(COLMN3 );
teradata
1 Answers

#1: Stats on a Volatile Table are stored in memory only, not in the data dictionary -> no row updated.

#2: The 1st collect creates a multi-column statistics, the other ones are single column.

To see the actual data use help stats on test1; and show stats values on test1;

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