Hello, paulruizendaal!

Thursday, October 20, 2005, 1:35:18 PM, you wrote:

p> How about some OLAP-type queries:
p> - how many orders did we ship last month?

If you want to know - store daily count.
Intermediate aggregates is a powerful thing.
If you have ~1000 orders per day, storing
daily order count will take 1000 times less
records to count montly orders count.
Initially trying to count raw data seems strange,
isn't it?

p> - how many customers have ordered widget X?
p> Or think about a web forum, displaying the number of reads, comments,
p> etc. for a specific article.

Another issue. Anyway, with MGA different transactions can
see different count's. Blocking servers uses indices to get
count, so here they are fast.

p> I agree that index-based count(*) is probably not a must-have feature,
p> but to discount it wholesale is a bit steep, I think.

Already discussed. Adding transaction number will enlarge
key size and slowdown some other processes in server.
Double-edged sword.

--
Dmitri Kouzmenko, www.ibanalyst.com