Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
![]() |
![]() |
Home -> Community -> Mailing Lists -> Oracle-L -> dbms_HASH...or something like it?...comparing data...
Need some help.
Developer has a wide table...20 columns.
He would like to add a 21st column to the table.
Then he would like to (be able to) store the first=20
20 columns data in concatenated form in the 21st column.
For example;
col1, col2, col3
Joe,Smith,JoeSmith
No problem PL/SQL program can handle this, BUT he would rather store the 20 concatenated columns in=20 a simpler, tighter form. He suggested "hashing" the=20 20 concatenated columns to (I guess) an Alphanumeric string?
And given that this is possible, what would be the=20 best/required data type for the hashed data?
Why you ask?
Because he want to be able to compare rows=20
(against new data) simply and quickly without selecting and=20
concatenating all 20 originally columns.
So he would store the hashed version of a row (data) on Insert.
Then on Update using a function hash the update data and compare
it to the already hashed value in the row.
=20
Any help is appreciated?
Any other solution is appreciated, BUT his program is limited and=20
can only S,I,U,D and call PROCEDURES or FUNCTIONS.
Please reply directly to me as well as to the list.
Thanks in advance,
Chris Marquez
Oracle DBA
HEYMONitor(tm) - heymonitor.com
"Oracle Monitoring & Alerting Solution"
-- http://www.freelists.org/webpage/oracle-lReceived on Sat Jan 22 2005 - 18:06:52 CST
![]() |
![]() |