Tim

I´ve been looking the source code of DBISAM (specifically at dbisamen.pas)
and I have a doubt about
TableMaxReadLockCount.

It can´t be set to 0 (no locks) and the default value is 100. For each 100
records browsed (internally by engine) there is a lock/unlock situation.
Some time ago, I have made some tests and check performance impact changing
this value to 1 for example and I have realized this became better for
shortest values. I know that there are concurrency problems with table
(100.000 records locked) but I have a lot of SQL that query old data (no
updates) and therefore I think this is not necessary to lock the table to
prevent updates. It will improve a lot the performance of SQL query.

My question:
It can´be changed to 0 (no locks) ?

Eduardo

Eduardo,

<< It can´t be set to 0 (no locks) and the default value is 100. For each
100 records browsed (internally by engine) there is a lock/unlock situation.
Some time ago, I have made some tests and check performance impact changing
this value to 1 for example and I have realized this became better for
shortest values. I know that there are concurrency problems with table
(100.000 records locked) but I have a lot of SQL that query old data (no
updates) and therefore I think this is not necessary to lock the table to
prevent updates. It will improve a lot the performance of SQL query.

My question:
It can´be changed to 0 (no locks) ? >>

No, it has to be 1 or higher.  Setting it to 0 does not prevent the initial
lock, it would simply prevent DBISAM from ever releasing the lock, which
would cause a serious issue with your database.

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim

> No, it has to be 1 or higher.  Setting it to 0 does not prevent the
> initial lock, it would simply prevent DBISAM from ever releasing the lock,
> which would cause a serious issue with your database.
Ok. Got it.

Eduardo