Historically, the initial catalog data to be installed during bootstrap
has been written in DATA() lines in the catalog header files. This had
lots of disadvantages: the format was badly underdocumented, it was
very difficult to edit the data in any mechanized way, and due to the
lack of any abstraction the data was verbose, hard to read/understand,
and easy to get wrong.
Hence, move this data into separate ".dat" files and represent it in a way
that can easily be read and rewritten by Perl scripts. The new format is
essentially "key => value" for each column; while it's a bit repetitive,
explicit labeling of each value makes the data far more readable and less
error-prone. Provide a way to abbreviate entries by omitting field values
that match a specified default value for their column. This allows removal
of a large amount of repetitive boilerplate and also lowers the barrier to
adding new columns.
Also teach genbki.pl how to translate symbolic OID references into
numeric OIDs for more cases than just "regproc"-like pg_proc references.
It can now do that for regprocedure-like references (thus solving the
problem that regproc is ambiguous for overloaded functions), operators,
types, opfamilies, opclasses, and access methods. Use this to turn
nearly all OID cross-references in the initial data into symbolic form.
This represents a very large step forward in readability and error
resistance of the initial catalog data. It should also reduce the
difficulty of renumbering OID assignments in uncommitted patches.
Also, solve the longstanding problem that frontend code that would like to
use OID macros and other information from the catalog headers often had
difficulty with backend-only code in the headers. To do this, arrange for
all generated macros, plus such other declarations as we deem fit, to be
placed in "derived" header files that are safe for frontend inclusion.
(Once clients migrate to using these pg_*_d.h headers, it will be possible
to get rid of the pg_*_fn.h headers, which only exist to quarantine code
away from clients. That is left for follow-on patches, however.)
The now-automatically-generated macros include the Anum_xxx and Natts_xxx
constants that we used to have to update by hand when adding or removing
catalog columns.
Replace the former manual method of generating OID macros for pg_type
entries with an automatic method, ensuring that all built-in types have
OID macros. (But note that this patch does not change the way that
OID macros for pg_proc entries are built and used. It's not clear that
making that match the other catalogs would be worth extra code churn.)
Add SGML documentation explaining what the new data format is and how to
work with it.
Despite being a very large change in the catalog headers, there is no
catversion bump here, because postgres.bki and related output files
haven't changed at all.
John Naylor, based on ideas from various people; review and minor
additional coding by me; previous review by Alvaro Herrera
Discussion: https://postgr.es/m/CAJVSVGWO48JbbwXkJz_yBFyGYW-M9YWxnPdxJBUosDC9ou_F0Q@mail.gmail.com
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
We have had support for restrictive RLS policies since 9.5, but they
were only available through extensions which use the appropriate hooks.
This adds support into the grammer, catalog, psql and pg_dump for
restrictive RLS policies, thus reducing the cases where an extension is
necessary.
In passing, also move away from using "AND"d and "OR"d in comments.
As pointed out by Alvaro, it's not really appropriate to attempt
to make verbs out of "AND" and "OR", so reword those comments which
attempted to.
Reviewed By: Jeevan Chalke, Dean Rasheed
Discussion: https://postgr.es/m/20160901063404.GY4028@tamriel.snowman.net
Fix unsafe coding around PG_TRY in RelationBuildRowSecurity: can't change
a variable inside PG_TRY and then use it in PG_CATCH without marking it
"volatile". In this case though it seems saner to avoid that by doing
a single assignment before entering the TRY block.
I started out just intending to fix that, but the more I looked at the
row-security code the more distressed I got. This patch also fixes
incorrect construction of the RowSecurityPolicy cache entries (there was
not sufficient care taken to copy pass-by-ref data into the cache memory
context) and a whole bunch of sloppiness around the definition and use of
pg_policy.polcmd. You can't use nulls in that column because initdb will
mark it NOT NULL --- and I see no particular reason why a null entry would
be a good idea anyway, so changing initdb's behavior is not the right
answer. The internal value of '\0' wouldn't be suitable in a "char" column
either, so after a bit of thought I settled on using '*' to represent ALL.
Chasing those changes down also revealed that somebody wasn't paying
attention to what the underlying values of ACL_UPDATE_CHR etc really were,
and there was a great deal of lackadaiscalness in the catalogs.sgml
documentation for pg_policy and pg_policies too.
This doesn't pretend to be a complete code review for the row-security
stuff, it just fixes the things that were in my face while dealing with
the bugs in RelationBuildRowSecurity.
As pointed out by Robert, we should really have named pg_rowsecurity
pg_policy, as the objects stored in that catalog are policies. This
patch fixes that and updates the column names to start with 'pol' to
match the new catalog name.
The security consideration for COPY with row level security, also
pointed out by Robert, has also been addressed by remembering and
re-checking the OID of the relation initially referenced during COPY
processing, to make sure it hasn't changed under us by the time we
finish planning out the query which has been built.
Robert and Alvaro also commented on missing OCLASS and OBJECT entries
for POLICY (formerly ROWSECURITY or POLICY, depending) in various
places. This patch fixes that too, which also happens to add the
ability to COMMENT on policies.
In passing, attempt to improve the consistency of messages, comments,
and documentation as well. This removes various incarnations of
'row-security', 'row-level security', 'Row-security', etc, in favor
of 'policy', 'row level security' or 'row_security' as appropriate.
Happy Thanksgiving!
Tom Lane
Bruce Momjian
Stephen Frost