RE: null columns and memory?
- From: "Justin Cave (DDBC)" <jcave@xxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 27 Sep 2005 15:25:13 -0600
There may be a question of context here as well.
So long as we are talking about database blocks, the block will look
identical whether it happens to reside on disk or in RAM. If and when
you have a chunk of PL/SQL code that declares a VARCHAR2 (<2000) in
order to read data from that block so you can act upon it
programmatically, however, Oracle will reserve a chunk of memory for
that local variable that is the maximum size it can attain..
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:15426
06219593
Justin Cave
Distributed Database Consulting, Inc.
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Paul Baumgartel
Sent: Tuesday, September 27, 2005 4:27 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: Re: null columns and memory?
In memory where? Space is reserved in DB blocks (formerly via PCTFREE,
now via ASSM) for operations that increase the storage requirements of
the block--such as updating a character string to a longer string, or
supplying a value in a column that formerly contained none.
On 9/27/05, ryan_gaffuri@xxxxxxxxxxx <ryan_gaffuri@xxxxxxxxxxx > wrote:
Someone at work told me the following. Having trouble confirming it in
the docs.
If you have a table with a nullable varchar column. If the field is left
null no space will be taken up in the database. However, space will be
reserved in memory for the column. Is this correct?
--
Paul Baumgartel
paul.baumgartel@xxxxxxxxxxxx
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