If you can afford the overhead in terms of disk space, you may consider
using a Snapsnot. Of course, you'll still have to put adequate indexes on
the snapshot and be careful when you refresh it.
--
Karl
Oracle Certified DBA
Nighr wrote in message <19980102223701.RAA21024_at_ladder02.news.aol.com>...
>In article <6777t9$ii4$0_at_204.179.92.82>, dshi_at_magpage.com (David Shi)
writes:
>
>>
>Suppose you have two very large tables which you joined together
>frequently,
>>the contents in the two tables do not change. Instead of
sort and merge the
>>two table every time to join the two, is it
possible to have certain kind of
>>link which once setup the first time,
can be used each time later for the
>>table join?
>
>I know cluster can help for such situations but I would like to
>>avoid
>it.
>
>If the above is impossible, then if the key columns used to join
>>in
>the two tables are sorted, will Oracle aware that and directly merge
>the
>>two when joining the two (thus skip the expensive sorting part)?
>
>You may want to look into foreign keys and views. The foreign key
constraint
>will enforce the relationship between the tables and build the index you
need.
>If you use a view to access the data from both of the tables, the join will
be
>done the same way every time. The other advantage of the view is that if
you
>still think that you're not getting the performance you want, just modify
the
>view--not your application code. Since you're keeping the data in separate
>segments, versus combining them into a cluster, you can still access either
>table fairly efficiently. The only clusters I have on my system is within
the
>SYSTEM table space--not in my applications!
>
>--Bob.
>
>
begin 666 Karl E. Jørgensen.vcf
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`
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Received on Sun Jan 04 1998 - 00:00:00 CST
