Subject | Re: Active transactions (benchmark results - updated) |
---|---|
Author | k_smith_000 |
Post date | 2005-10-18T21:25:09Z |
--- In firebird-support@yahoogroups.com, "Ann W. Harrison"
<aharrison@i...> wrote:
Do the LockHashSlots has any impact on the speed on hash function?
If not, why can't we set LockHashSlots to maximum value...
Best regards,
Kevin Smith
<aharrison@i...> wrote:
> Ah. Check here: www.ibdeveloper.com for a full explanation. Theshort
> version is that the Firebird lock manager locates resources through aThe
> 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 slotThe shorter hash chain, the faster object lookup.
> 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.
Do the LockHashSlots has any impact on the speed on hash function?
If not, why can't we set LockHashSlots to maximum value...
>Definitely it is :( Thanks a lot!
> > "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.
Best regards,
Kevin Smith