Re: Larry Ellison and million bucks!

Snorri Bergmann <snorri_at_strengur.is> wrote:
>
>You can argue that these periodic (canned) reports will benefit greatly
>from this feature. However, most OLAP and report tools (example: Crystal
>Reports) have the facilility to run a report once, and the distribute it
>to the approptiate audience via Intranet. This should be much more
>efficient because load times (and disk space) is much affected by
>pre-computing everything. ........

The main advantage of summary tables does not come from running the same report many times. Suppose you have precomputed ( put into a separate table) the following :

SELECT key1,key2,key3,key4, sum(f1) as totf1, sum(f2) as totf2, sum(f3) as totf3
FROM <whatever>
GROUP BY key1,key2,key3,key4

Then all the following selects could benefir from this pre-aggregation:

SELECT key1, sum(f2)
FROM <same as above>
GROUP BY key1

SELECT key2,key4, sum(f1)
FROM <same as above>
WHERE<some_condition_on_key1>
GROUP BY key2,key4

SELECT key3,key2,key4, sum(f3),sum(f1)
FROM <same as above>
GROUP BY key3,key2,key4

.........
and a bunch of other permutations

But this does not have to be built into the db engine, decent OLAP tools can do that easily. Received on Mon Nov 30 1998 - 00:00:00 CST