Because we assume that int64 and double have the same alignment
requirement, AIX's default behavior that alignof(double) = 4 while
alignof(int64) = 8 is a headache. There are two issues:
1. We align both int8 and float8 tuple columns per ALIGNOF_DOUBLE,
which is an ancient choice that can't be undone without breaking
pg_upgrade and creating some subtle SQL-level compatibility issues
too. However, the cost of that is just some marginal inefficiency
in fetching int8 values, which can't be too awful if the platform
architects were willing to pay the same costs for fetching float8s.
So our decision is to leave that alone. This patch makes our
alignment choices the same as they were pre-v17, namely that
ALIGNOF_DOUBLE and ALIGNOF_INT64_T are whatever the compiler prefers
and then MAXIMUM_ALIGNOF is the larger of the two. (On all supported
platforms other than AIX, all three values will be the same.)
2. We need to overlay C structs onto catalog tuples, and int8 fields
in those struct declarations may not be aligned to match this rule.
In the old branches we had some annoying rules about ordering catalog
columns to avoid alignment problems, but nobody wants to resurrect
those. However, there's a better answer: make the compiler construe
those struct declarations the way we need it to by using the pack(N)
pragma. This requires no manual effort to maintain going forward;
we only have to insert the pragma into all the catalog *.h files.
(As the catalogs stand at this writing, nothing actually changes
because we've not moved any affected columns since v16; hence no
catversion bump is required. The point of this is to not have
to worry about the issue going forward.)
We did not have this option when the AIX port was first made. This
patch depends on the C99 feature _Pragma(), as well as the pack(N)
pragma which dates to somewhere around gcc 4.0, and probably doesn't
exist in xlc at all. But now that we've agreed to toss xlc support
out the window, there doesn't seem to be a reason not to go this way.
In passing, I got rid of LONGALIGN[_DOWN] along with the configure
probes for ALIGNOF_LONG. We were not using those anywhere and it
seems highly unlikely that we'd do so in future. Instead supply
INT64ALIGN[_DOWN], which isn't used either but at least could
have a good reason to be used.
Discussion: https://postgr.es/m/1127261.1769649624@sss.pgh.pa.us
Add "IWYU pragma: export" annotations in each catalog header file so
that, for instance, including "catalog/pg_aggregate.h" is considered
acceptable in place of "catalog/pg_aggregate_d.h". This is very
common and it seems better to silence IWYU about it than trying to fix
this up.
Discussion: https://www.postgresql.org/message-id/flat/9395d484-eff4-47c2-b276-8e228526c8ae@eisentraut.org
Run renumber_oids.pl to move high-numbered OIDs down, as per pre-beta
tasks specified by RELEASE_CHANGES. For reference, the command was
./renumber_oids.pl --first-mapped-oid 8000 --target-oid 6205
This is needed so that renumber_oids.pl can handle renumbering
shared catalog declarations, which need to provide C macros for
the OIDs of the shared toast table and index. The previous
method of writing a C macro separately was error-prone anyway.
Also teach renumber_oids.pl about DECLARE_UNIQUE_INDEX_PKEY,
as we missed doing when inventing that macro.
There are no changes to postgres.bki here, so no need for a
catversion bump.
Discussion: https://postgr.es/m/2995325.1650487527@sss.pgh.pa.us
This patch allows "PGC_SUSET" parameters to be set by non-superusers
if they have been explicitly granted the privilege to do so.
The privilege to perform ALTER SYSTEM SET/RESET on a specific parameter
can also be granted.
Such privileges are cluster-wide, not per database. They are tracked
in a new shared catalog, pg_parameter_acl.
Granting and revoking these new privileges works as one would expect.
One caveat is that PGC_USERSET GUCs are unaffected by the SET privilege
--- one could wish that those were handled by a revocable grant to
PUBLIC, but they are not, because we couldn't make it robust enough
for GUCs defined by extensions.
Mark Dilger, reviewed at various times by Andrew Dunstan, Robert Haas,
Joshua Brindle, and myself
Discussion: https://postgr.es/m/3D691E20-C1D5-4B80-8BA5-6BEB63AF3029@enterprisedb.com
