Archives of the TeradataForum
Message Posted: Mon, 16 Jan 2012 @ 15:07:51 GMT
| Subj: || || Re: Compress Null value |
| From: || || Newell, Ray |
Nulls are not automatically compressed. If the column is defined as, for example, CHAR(20) and it is null, Teradata will store 20 spaces in
the row and set a presence bit to indicate that the value is not spaces but null.
So if you want to save space and you have a lot of nulls in a column, then you must compress it. The amount of space savings depends on the
column size and the number of rows that have nulls. The same goes for numeric fields except Teradata will store zeros instead of blanks.