Need Your comments please!!!!

Question

HI,
I have four tables like below.
region_master(regionid, region_name)
country_master (country_id, country_name)
state_master(stateid, stte_name)
user_master(user_id,user_name,user_regionid,user_countryid,user_stateid, user_cityname);
Now I want to find our the users who matches to the search words using the intermedia search,
For this I am feeling two ways of searching
1. Searching all the tables with join queries,
2. Making a new column LOCATION in the user_master table and putting the concatenated value of region,country,state,city in it.
So I feel by doing the first way is the exact normalizatin, Doing the second way is some what aquard.
But I feel as I am using the intermedia search , to maintain the indexes and to reduce the number of indexes, and to retrieve from the one table without joins is preferable then joins.
But any way I feel following the first way is the good thing...
So if any comments, you are most welcome... with reasons.
Thanks in advance,
Khaleel.

Answer 1

You are right to be cautious. De-norm,alisation is inherently a bad thing, and only to be approached when you know you have a performance problem that cannot be solved any other way. First of all you ought to try the four table join route and establish that that is too slow and cannot be improved upon.
In that circumstance you need to answer two further questions:
Is the USER_MASTER table fairly stable (i.e. few updates (in particular location derived stuff) and few inserts)?
Is this particular query going to be run often (i.e. at least several times an hour)?
If the answers to both those questions are 'Yes' then de-normalisation is worth the hassle of supporting it. Bear in mind that if you are using STATE_MASTER, etc. as foreign key references to USER_MASTER that can cause the mutating table problem (ORA-4091, ORA-4094), so denormalising via triggers is a bag o' tricks in its own right.
Cheers, APC