Craig A. James schrieb:
Tino Wildenhain wrote:
You guys can correct me if I'm wrong, but the key feature that's
missing from Postgres's flexible indexing is the ability to maintain
state across queries. Something like this:
select a, b, my_index_state() from foo where ...
offset 100 limit 10 using my_index(prev_my_index_state);
Yes, you are wrong :-) The technique is called "CURSOR"
if you maintain persistent connection per session
(e.g. stand allone application or clever pooling webapplication)
That's my whole point: If relational databases had a simple mechanism
for storing their internal state in an external application, the need
for cursors, connection pools, and all those other tricks would be
eliminated.
Well the cursor is exactly the simple handle to the internal
state of the relational db you are looking for.
Do you really think transferring the whole query-tree, open index
and data files to the client over the network would really improve
the situation?
As I said earlier, relational technology was invented in an earlier era,
and hasn't caught up with the reality of modern web apps.
There is nothing modern with todays web apps.
If its a naive web application you just store your session
in tables where you can easily maintain the scroll state
as well.
One thing I've learned in 25 years of software development is that
people who use my software have problems I never imagined. I've been
the one who was naive when I said similar things about my customers, and
was later embarrassed to learn that their problems were more complex
than I ever imagined.
Sure it really depends on the application how the best solution
would look like but I'm quite certain, counterfaiting internal
stuff of the underlying relational database in the application
makes more problems then it solves. If you can't handle SQL,
dont use SQL, you can build web applications w/o any relational
database if you want it.
Regards
Tino Wildenhain
