Re: [GENERAL] advisory locks: documentation hint and feature request

Marc Mamin wrote:
> doing this, I missed an information in the documentation that would be
> useful to add:
>
>
> pg_locks columns definition
> ---------------------------
>
> current definition:
>
> objid : OID of the object within its system catalog,
> or NULL if the object is not a general database object
>
> to add: "For advisory locks it is used to distinguish the two key
> spaces (one int8 or two int4 keys)
>
>
> Table 9-56. Advisory Lock Functions (8.3 Beta)
> -----------------------------------
> current: (note that these two key spaces do not overlap)
>
> to add: "; The two key spaces are separated on the column objid in the
> pg_locks view"
>

I have added your suggested changes to the docs with the attached patch.
Thanks.

> Moreover I missed some function that would allow a cleaner
> implementation of my features
> (reducing the need to query the pg_locks view)
>
> For example:
>
> --current shared lock count (owned / all)
> pg_advisory_lock_shared_count_my(key bigint)
> pg_advisory_lock_shared_count_all(key bigint)
>
>
> --enforce exclusive locks so that they cannot be stacked
> pg_try_advisory_lock_single(key bigint)

Sorry, I am afraid they would not have general-enough usefulness.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com

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