Subject Re: Active transactions (benchmark results - updated)
Author k_smith_000
--- In, "Ann W. Harrison"
<aharrison@i...> wrote:
> Ah. Check here: for a full explanation. The
> version is that the Firebird lock manager locates resources through a
> hash lookup on the object name. The name is transformed through a hash
> function into one of n values, where n is the number of hash slots.
> object is then added to a linked list called a hash chain for that slot
> values. If you have m objects, the average length of a chain is m/n.
> > #LockHashSlots = 101
> > Has anyone played with this parameter?
> Often, and with considerable effect.
The shorter hash chain, the faster object lookup.
Do the LockHashSlots has any impact on the speed on hash function?
If not, why can't we set LockHashSlots to maximum value...

> > "In Classic mode, the size given is used for the initial allocation.
> > The table expands dynamically up to the limit of memory."
> > I'm using CS so this one is not for me;)
> That's misleading. The table expands up to the limit set by the
> configuration parameter, not until it fills all of memory.
Definitely it is :( Thanks a lot!

Best regards,
Kevin Smith