Re: remove unnecessary include in src/backend/commands/policy.c

On 2025-Sep-30, Shinya Kato wrote:

> However, the changes make policy.c rely on transitive includes. For
> example, policy.c uses GETSTRUCT(), which is defined in
> access/htup_details.h. Instead of being included directly, that header
> is currently pulled in via a fairly long chain:
> catalog/indexing.h -> nodes/execnodes.h -> access/tupconvert.h ->
> executor/tuptable.h -> access/htup_details.h
> 
> While this works for now, the dependency is fragile and could break if
> header files are rearranged in the future. I'm not sure this is a good
> practice, and although I couldn't find a specific rule against it in
> PostgreSQL's coding conventions, it seems risky.

Yeah -- I'm not very worried about the fragility being introduced, since
if such a problem ever occurs it's very obvious and easy to fix.
However, removing these include lines is just churn with no benefit,
because those includes are still being processed via the indirect
pathways.  We haven't saved anything.

Just look at all the crossed wires here
https://doxygen.postgresql.org/policy_8c.html
Clearly the cross-inclusion of headers in headers is a mess.  Fixing
that mess is going to cause *more* explicit inclusion of headers in .c
files.  Removing a few explicit ones so that they become implicit, only
to have to resurrect the explicit inclusion when we remove some of that
cross-header inclusion is pointless.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"Doing what he did amounts to sticking his fingers under the hood of the
implementation; if he gets his fingers burnt, it's his problem."  (Tom Lane)