Re: How to insert records by descending order of date ...

In article <42pj1j$o62_at_ixnews2.ix.netcom.com>, chuckh_at_ix.netcom.com (Chuck Hamilton) wrote:

> As stated before, in an RDBMS it's irrelevant. The only time it might
> be relevant is to speed up the loading of data if you're
> simultaneously creating indexes. If that's the case, just sort the
> input data by date in descending order.

In a perfect world all RDBMS would perfectly optimize all relational queries. The problem is we are stuck with SQL. SQL only meets some of the 12 fidelity rules of the relation database model and therefore rule 0 (foundation) is not satisfied. Which means non-relational work arounds are neccessary to make a usable DBMS.

One of those non-relational things I have done with Sybase was the ability to guarantee the physical order of rows in a table. I don't know if I can do this with Oracle.

There are other things that matter in Oracle's (I am sure this applies to other vendors as well) implementation of SQL that are "irrelevant" in an RDBMS. The order of a where clause can have a significant impact on the parse time. My tech. lead insists that the order of tables in the from clause of a select affects execution time.

These things are all supposedly "irrelevant" in a relational-model database. But the real-world tells me otherwise.

-- 
Ed Bruce
edward_at_igate1.hac.com
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