wongj@hpsgm2.sgp.hp.com (Jimmy Wong) (10/04/90)
I am designing a relational database that need to join information from quite a number of tables. Can someone tell me will there be a difference in performance if I join the information using a view as oppose to joining the information at run-time ? Thank you in advance. -- Jimmy Wong phone: +65 279-8755 Singapore Networks Operation Unix mail: wongj@hpsgm2.sgp.hp.com Hewlett-Packard 1150 Deport Road Singapore 0410
davidm@uunet.UU.NET (David S. Masterson) (10/05/90)
In article <1070003@hpsgm2.sgp.hp.com> wongj@hpsgm2.sgp.hp.com (Jimmy Wong) writes: I am designing a relational database that need to join information from quite a number of tables. Can someone tell me will there be a difference in performance if I join the information using a view as oppose to joining the information at run-time ? In theory, there will be little difference as the information in the view must still be processed by the query optimizer. What can help the joins more is clustering that some relational database systems implement. That is, some database systems allow keys from multiple tables to be clustered in the same data pages which reduces the number of disk accesses because it will be more likely that, after fetching A to join to B, B will be in memory. Your mileage may vary from system to system. -- ==================================================================== David Masterson Consilium, Inc. uunet!cimshop!davidm Mtn. View, CA 94043 ==================================================================== "If someone thinks they know what I said, then I didn't say it!"