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

cschang wrote:

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@x.washington.edu
(replace 'x' with 'u' to respond)