Re: Are trailing null columns stored?

From: <fgreene_at_hayes.com>
Date: 7 Jun 93 07:29:33 EDT
Message-ID: <7402.2c12ee5d_at_hayes.com>


In article <1993Jun4.134837.18974_at_uvm.edu>, wvw_at_moose.uvm.edu (Warren Van Wyck) writes:
> V6 System Architecture training Doc (page 1-40) states:
> "Trailing null fields not stored"
>
> I tried a test. I inserted a row with both an embedded null column (field)
> and some trailing null fields. After a commit and checkpoint, I dumped the
> relevant Oracle block. It appears that both the embedded null field and
> the trailing ones use one byte of disk storage each -- it's value is x'ff'.
>
> This is of limited practical significance (since we don't have many rows
> with trailing null fields), but I am curious what the facts really are.
> Does anyone have a definitive answer?
>
> We are running Oracle 6.0.34.3.1 (TPO) under AIX 3.2.
>
> Warren Van Wyck University of Vermont wvw_at_moose.uvm.edu (802)656-8421
> --
> Warren Van Wyck Analyst/Programmer (802)656-8421
> University of Vermont, Computing and Information Technology
> Internet: wvw_at_moose.uvm.edu

Trailing columns are supressed during output. Simple case,

	Use a sql statement to create a comma delimited ASCII file for
	subsequent use as as input to Microsoft WORD merge program.  If
	the final column (say salutation) is null, Oracle supresses it
	and later the WORD program goes bananas.

	Solution, always make sure that the last column is NOT null by
	using a dummy field.  Something like 

	SELECT col1, col2, col3, '999'
	etc
Received on Mon Jun 07 1993 - 13:29:33 CEST

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