Re: Does Trim function is automatically apply to char datatype in 9i

cschang wrote:

> We have an old database. Some of the columns were built with char data
> type. We used to use the Trim() or RTRIM() to trim off the space before
> comparison, such as in left side of where condition ( where Trim(col1) =
> value). Our DBA told us that using the 9i applies the Trim
> automatically already so we do not need the RTrim(). Apparently that
> was not what I saw. I search some web sites and other places, found no
> mentioned about these features. Because adding the trim will cause our
> performance, any other way to avid to use it (besides to convert char
> type to varchar2 type)? Appreciate anyone’s suggestions.
>
> C Chang

Two suggestions:

1. Rather than asking create a little table and check it out.

CREATE TABLE t (
testcol CHAR(20));

INSERT INTO t VALUES ('x');
COMMIT; SELECT LENGTH(testcol) FROM t;

ALTER TABLE t
MODIFY testcol VARCHAR2(20);

SELECT LENGTH(testcol) FROM t;

UPDATE t SET testcol = TRIM(testcol);
COMMIT; SELECT LENGTH(testcol) FROM t;

2. Get a new DBA.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)