MySQL - Blockfactor

[drmaves]

Does MySQL support the attribute Blockfactor in CFQUERY?

[cf_menace]

Never heard of Blockfactor before. Had to Google it. There's no results for
"blockfactor" when searching MySQL.com, so I'd say it doesn't support it.
Howver, I believe the funcitonality you're trying to get is the same thing that
LIMIT furnishes.

SELECT someID, someLabel
FROM someTable
LIMIT #x# OFFSET #y#

LIMIT tells MySQL to return only "X" number or rows at a time. OFFSET tells
MySQL to start at row "Y".

HTH

[Neculai Macarie]

> Does MySQL support the attribute Blockfactor in CFQUERY?

It certainly doesn't error on it. In CFMX 6 it says it applies to ORACLE
native drivers, in CFMX7 it says that it might not be supported by some db
systems.

--
<mack />

[drmaves]

cf_menance,

LIMIT actual limits the number of records returned so if your query found 100
records and your limit was set to 10 you would only have 10 records to work
with.

BLOCKFACTOR is different. It's supposed give CF a heads up on whether to
expect a large number of records or just one or two. The end result is that you
still have all the records selected to work with as opposed to LIMIT. Evidently
you can improve performance by giving CF an estimate of the number of records
it might expect to receive.

[drmaves]

Neculai,

I read the CF docs on this as well; however, "might not be supported by some
db systems" is pretty vague if you ask me.
It still doesn't say specifically whether MySQL supports it.

I as well do not get an error but I'm wondering if it's having any effect or
is only a waste of my time using the setting.

[Neculai Macarie]

> Neculai,

>
> I read the CF docs on this as well; however, "might not be supported by

some

> db systems" is pretty vague if you ask me.
> It still doesn't say specifically whether MySQL supports it.
>
> I as well do not get an error but I'm wondering if it's having any effect

or

> is only a waste of my time using the setting.

I did some pretty basic testing and and it had no noticeable effect on the
speed of the queries.

--
<mack />

[drmaves]

After an inquiry to Macromedia support the answer seems to be that the MySQL drivers that ship with MySQL 7 do not support BLOCKFACTOR.