Archives of the TeradataForum
Message Posted: Tue, 22 Mar 2005 @ 20:38:27 GMT
| Subj: || || Re: How to know the size of storage space of NUSI??? |
| From: || || Stover, Terry |
For a non-PPI table it's 8+ bytes per row, for PPI it's 10+ bytes per row. The 8 or 10 bytes is the rowid, the extra "+" depends on the
indexed column data types and distribution. With our data I have found the size to be 8.1 to 8.5 bytes per row, usually towards the 8.1 end.
Before creating any nusi's on a large table you should try collecting stats on the columns of interest. It may solve you're performance
problems, and if you end up creating a nusi you'll have to collect stats anyway. On your 2 billion row table the nusi will take > 16 Gig and
significantly impact load times. Even if it helps query performance it may not pass the cost/benefit test.