Very slow HREADSEEK

Hi all

A HREADSEEK being issued against a Firebird table's primary key (an integer) is taking 28s to come back the first time it is run. Subsequent reads of different rows are taking millisecounds. When using a HEXECUTEQUERY to do essentially the same read it takes millisecounds. A straight SQL query is similarly quick.

Does anyone know of any issues with HREADSEEK which could be causing this?

Using OLEDB driver, Firebird 2.

Rgds
Paul

G'day Paul

HReadSeek() will search for a match that is greater than or equal to the key but HReadSeekFirst() will search for the exact match.
The fact that HReadSeek() is a more general search may be the cause of the delay in Firebird. In HF there is no discernible difference between the two commands but it would be interesting to compare it to HReadSeekFirst() in Firebird

Regards
Al

Hi Al

Already tried that - no difference :-(

Also tried the exact match option in HReadSeek with no luck.

Any other ideas?

Rgds
Paul

All apologies, this is a test
Do not answer

Hi,

I believe having read time ago an explanation in a French forum that hReadSeek browses both file and index which makes it even slower on a Client/Server DB. The recommendation was to use hSeekFirst (acting on the index only), followed by a hRead on the current record if hSeekFirst was successful.

hSeekFirst also has the parameter hLimitParsing specifically for C/S.

Regards
Mat

p.s. I'm interested hearing about your experience with Firebird and OLEDB. What driver are you using?



Edited 1 time(s). Last edit at 04/02/2008 11:58PM by mat.

Hi Mat,

Thanks for the tip. Unfortunately it didn't help.

We're using the OLEDB driver from IBProvider.

Rgds
Paul.

Did you already try with sqlmanagerx? It is an ALTERnative access

see www.sqlmanagerx.com :spos:

best regards

Quote
Paul Turner
Hi Mat

Thanks for the tip. Unfortunately it didn't help.

We're using the OLEDB driver from IBProvider.

Rgds
Paul.

I tried Firebird with this driver and WD9 about two years ago but had to give up because of inconsistent behaviour and performance. At the time I didn't think the problem had to do with the driver because it worked perfectly well under MS Access.

Hope you'll have more success.

Regards
Mat

Our development started with IB Provider around 8 months ago. The system is running against of range of RDBMS - Firebird, MySQL, HFCS, MSSQL. The end user gets to chose. Whilst some of those perform better than others, all are providing consistently reliably performance.

Rgds
Paul