Re: Should vacuum process config file reload more often - Mailing list pgsql-hackers

> On 30 Mar 2023, at 04:57, Masahiko Sawada <sawada.mshk@gmail.com> wrote:

> As another idea, why don't we use macros for that? For example,
> suppose VacuumCostStatus is like:
>
> typedef enum VacuumCostStatus
> {
>    VACUUM_COST_INACTIVE_LOCKED = 0,
>    VACUUM_COST_INACTIVE,
>    VACUUM_COST_ACTIVE,
> } VacuumCostStatus;
> VacuumCostStatus VacuumCost;
>
> non-vacuum code can use the following macros:
>
> #define VacuumCostActive() (VacuumCost == VACUUM_COST_ACTIVE)
> #define VacuumCostInactive() (VacuumCost <= VACUUM_COST_INACTIVE) //
> or we can use !VacuumCostActive() instead.

I'm in favor of something along these lines.  A variable with a name that
implies a boolean value (active/inactive) but actually contains a tri-value is
easily misunderstood.  A VacuumCostState tri-value variable (or a better name)
with a set of convenient macros for extracting the boolean active/inactive that
most of the code needs to be concerned with would more for more readable code I
think.

--
Daniel Gustafsson