Re: [PATCH] Add GUCs for predicate lock promotion thresholds

ilmari(at)ilmari(dot)org (Dagfinn Ilmari Mannsåker) writes:

> One thing I don't like about this patch is that if a user has increased
> max_pred_locks_per_transaction, they need to set
> max_pred_locks_per_relation to half of that to retain the current
> behaviour, or they'll suddenly find themselves with a lot more relation
> locks. If it's possible to make a GUCs default value dependent on the
> value of another, that could be a solution. Otherwise, the page lock
> threshold GUC could be changed to be expressed as a fraction of
> max_pred_locks_per_transaction, to keep the current behaviour.

Another option would be to have a special sentinel (e.g. -1) which is
the default, and keeps the current behaviour.

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