Re: Library cache lock vs. pin

  • From: Harish Kalra <harish.kumar.kalra@xxxxxxxxx>
  • To: paul.baumgartel@xxxxxxxxx
  • Date: Tue, 31 Jan 2006 13:02:29 +0530

Paul:

Library cache locks are held on Library cache object handles whereas Library
cache pins held on data heaps.
Pins are held in shared mode to read data heap / to avoid modifications of
dependant objects.
Pins held in exclusive mode to mdify data heap.
Where as Library cache locks are held in exclusive mode to all parent and
child object handles and simultaneously held in shared mode for all
dependencies.

Thanks
-Harish Kalra



On 1/20/06, Paul Baumgartel <paul.baumgartel@xxxxxxxxx> wrote:
>
> Can someone on the list explain succinctly the difference between a
> library cache lock and a library cache pin, and why both of these
> concurrency control mechanisms are necessary?
>
> --
> Paul Baumgartel
> paul.baumgartel@xxxxxxxxxxxx
>
>

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