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Home -> Community -> Usenet -> c.d.o.misc -> Re: Space taken up by a CHAR variable
On Sat, 19 Apr 1997 21:17:07 -0400, Tansel <tansel_at_openix.com> wrote:
>Dear Oracle Users/DBA's,
>
>My question is:
>
>What is the space taken up by a CHAR field when it is not populated,
>i.e. when it is NULL?
>This is very important for me since I have to adjust my PCT_FREE and
>PCT_USED parameters for a 15 million record file accordingly. All the
>fields in the table are CHAR's. If ,when I create the table, the
>unpopulated fields take up as much space as their size, that means when
>I update these fields in future the record size is not going to get
>bigger, which also means my PCT_FREE can be a very small number. The
>only operations on the table are UPDATEs and INSERTs.
>
>Thanks..
>
>Tansel
It will take either 0 or 1 bytes when NULL.
If it is not the last column in the table AND some column after it in the create table is NOT null it will take 1 byte.
If it is the last column in the table OR every column after it is null, then it will take zero bytes.
It will always take a fixed length when NOT null.
Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government
Bethesda MD
http://govt.us.oracle.com/ -- downloadable utilities
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