Subject | Re: [IBO] SQL Hourglass et. al. |
---|---|
Author | Aage Johansen |
Post date | 2006-02-23T20:12:49Z |
Anthony Tanas wrote:
property (or two).
joins, don't use the old method of putting the join logic in the where
clause). Watch out for low-selectivity indexes, though.
Indexes for sorting (order by) is usually not a good idea.
You might find that Foreign Key constraints gives you an index with low
selectivity. It can be a problem in Fb/1.5, but less so in Fb/2.
Take a look at the plan for your queries, and ask on this list. There are
a few tricks tha can come in handy.
Helen's Firebird book may be the answer to a lot of questions.
--
Aage J.
> Hello everybody,:-)
> I'm new to IBObjects and to this list.
> I just converted my program over to the IBOBjects Tdataset module. It was
> amazingly fast and easy! I was so excited about jumping back on it today
> that I was up before the crack of 11 AM!
>Drop a TIB_SessionProps component on a form. You might need to set a
> My questions:
>
> 1) How can I reintroduce the "SQL Hourglass" behavior that I got with BDE
> components? Now I don't get an hour glass. In most places I can set
> Screen.Hourglass but I have a few databound grids with huge datasets that
> grind a bit when scrolling and get no hour glass at all.
property (or two).
> 2) How much of a performance gain would I get by converting my executed SQLSome, but not a lot (I would think). But you may find added functionality.
> statements (INSERT, UPDATE, DELETE) that are currently in the Tquery
> equivalent into the component (I forget what it's called) with the "low
> overhead" SQL components.
> 3) Please give me some pointers on indexing to increase efficiency. DuringUse indexes to support the WHERE clause. And for joins (do use explicit
> most of my career as a corporate programmer we had a DBA who took care of
> the database stuff like this. Now I'm on my own. Is setting up foreign key
> contraints important for performance or just for data integrity? What's a
> good place to learn about stored procedures?
joins, don't use the old method of putting the join logic in the where
clause). Watch out for low-selectivity indexes, though.
Indexes for sorting (order by) is usually not a good idea.
You might find that Foreign Key constraints gives you an index with low
selectivity. It can be a problem in Fb/1.5, but less so in Fb/2.
Take a look at the plan for your queries, and ask on this list. There are
a few tricks tha can come in handy.
> Like for example right now if I delete a Billing Number (like an invoice) inPut Referential Integrity constraints in the database.
> my system, I first delete the billing items, and before that the payments
> towards each item (it's medical related so payments are for individual
> items)...and I do this in my client program by executing delete statements.
> Is this something that should be done on the server (I seem to recall
> something about ON DELETE CASCADE from my database class in college).
>
> On the other hand if I move functionality to the server then I am going to
> be more tightly attached to firebird. Is this a good bet?
Helen's Firebird book may be the answer to a lot of questions.
--
Aage J.