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Author Which is faster DBFNTX or DBFCDX?
Ollie

2006-06-26, 6:55 pm

Which is faster DBFNTX or DBFCDX?

Which one is better? Why?


Turan Fettahoglu

2006-06-27, 7:55 am

> Which is faster DBFNTX or DBFCDX?
DBFCDX is lots and lots faster.

> Which one is better? Why?

DBFCDX. If you introduce a new index in a separate .ntx file you have to
rewrite every USE command for the table in question. If you fail to open the
new index it will not be updated and you will get an index error sooner or
later.

USE a .DBF with a .CDX file and the .CDX file will open automatically with
all index tags inside - even the newly introduced ones.

Switch to .cdx indexes as soon as you can and you'll be glad about it soon.

HTH
Turan


Przemyslaw Czerpak

2006-06-27, 6:55 pm

On Mon, 26 Jun 2006 22:11:36 +0200,
Ollie <ollie1@theoasis.co.za> wrote:
> Which is faster DBFNTX or DBFCDX?


If you ask about internal core code then DBFNTX.
If you ask what give you better performance in typical
installation then DBFCDX.

> Which one is better? Why?


In the environment you probably will use it DBFCDX.
It compress keys in leaf nodes what noticeable reduce
index size. When IO operations are critical for performance
DBFCDX will give better results though core RDD code is much
slower, f.e. in CL5.3 about 3 times but we have fast CPU and
disks/networks are usually many times slower then RAM so the
total performance for big files will be much better with
DBFCDX. Of course if you have some dedicated machine with a
lot of RAM for IO buffers and fast IO operation supported by
OS then forget about CDX format. It will have no chance in
comparison to NTX.

best regards,
Przemek
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