Subject Re: [firebird-support] Re: Active transactions (benchmark results - updated)
Author Ann W. Harrison
k_smith_000 wrote:
> #
> # Tune lock hash list; more hash slots mean shorter hash chains.
> I don't get this :(

Ah. Check here: for a full explanation. The short
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. The
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.

> "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.