Re: Delay locking partitions during query execution - Mailing list pgsql-hackers

On 2019/01/04 9:53, David Rowley wrote:
> Without PREPAREd statements, if the planner itself was unable to prune
> the partitions it would already have obtained the lock during
> planning, so AcquireExecutorLocks(), in this case, would bump into the
> local lock hash table entry and forego trying to obtain the lock
> itself.  That's not free, but it's significantly faster than obtaining
> a lock.

Hmm, AcquireExecutorLocks is only called if prepared statements are used
and that too if a generic cached plan is reused.

GetCachedPlan -> CheckCachedPlan -> AcquireExecutorLocks

In GetCachedPlan:

    if (!customplan)
    {
        if (CheckCachedPlan(plansource))


Thanks,
Amit