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Home -> Community -> Mailing Lists -> Oracle-L -> RE: what is wrong with this idea ...
Gene - What is the motivation here? Are you trying to save space in a fact
table with many, many rows? I agree that in data warehousing we sometimes
violate the normal rules we adhere to in OLTP databases, and I think some of
your responses have been assuming OLTP rules. For example, someone pointed
out that updating might cause inconsistencies, etc. Well, in a data
warehouse you usually write once, read many. You may never update the data,
depending on the warehouse. Is your tradeoff between four separate columns
or a single column with concatenated values?
Dennis Williams
DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Wednesday, August 14, 2002 8:19 AM
To: Multiple recipients of list ORACLE-L
Hi. We have a table in our data warehouse which keeps info about calls made. This table has a child table with some detailed information about parts of the call. There may be any number of "parts" within a call (1 to many) and every part has a status.
MY developer wants to add a string field to the parent table which will concatinate all the statuses for all the parts within this call. For example if a call has 4 parts and their statuses are "A","B","A" and "F", the value of that field will be "ABFA". Then the developer will be able to query smalle parent table instead of a large child table in order to see how many calls had at least one part with status "A" or statuses "A" and "F" etc by using a INSTR (or SUBSTR) command.
Would it be better (from performance/CPU standpoint) to add several separate fields: STATUS_A_CNT, STATUS_B_CNT (the list of status codes is fairly static) instead? There is something about this string that rubs me the wrong way, but I can't put my finger on it.
Any thoughts?
thank you
Gene
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Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists --------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed Aug 14 2002 - 10:28:39 CDT
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