Update the built-in logical replication system to make use of the
previously added logical decoding for TRUNCATE support. Add the
required truncate callback to pgoutput and a new logical replication
protocol message.
Publications get a new attribute to determine whether to replicate
truncate actions. When updating a publication via pg_dump from an older
version, this is not set, thus preserving the previous behavior.
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Marco Nenciarini <marco.nenciarini@2ndquadrant.it>
Author: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
pg_dump supposed that a stats object necessarily shares the same schema
as its underlying table, and that it doesn't have a separate owner.
These things may have been true during early development of the feature,
but they are not true as of v10 release.
Failure to track the object's schema separately turns out to have only
limited consequences, because pg_get_statisticsobjdef() always schema-
qualifies the target object name in the generated CREATE STATISTICS command
(a decision out of step with the rest of ruleutils.c, but I digress).
Therefore the restored object would be in the right schema, so that the
only problem is that the TOC entry would be mislabeled as to schema. That
could lead to wrong decisions for schema-selective restores, for example.
The ownership issue is a bit more serious: not only was the TOC entry
potentially mislabeled as to owner, but pg_dump didn't bother to issue an
ALTER OWNER command at all, so that after restore the stats object would
continue to be owned by the restoring superuser.
A final point is that decisions as to whether to dump a stats object or
not were driven by whether the underlying table was dumped or not. While
that's not wrong on its face, it won't scale nicely to the planned future
extension to cross-table statistics. Moreover, that design decision comes
out of the view of stats objects as being auxiliary to a particular table,
like a rule or trigger, which is exactly where the above problems came
from. Since we're now treating stats objects more like independent objects
in their own right, they ought to behave like standalone objects for this
purpose too. So change to using the generic selectDumpableObject() logic
for them (which presently amounts to "dump if containing schema is to be
dumped").
Along the way to fixing this, restructure so that getExtendedStatistics
collects the identity info (only) for all extended stats objects in one
query, and then for each object actually being dumped, we retrieve the
definition in dumpStatisticsExt. This is necessary to ensure that
schema-qualification in the generated CREATE STATISTICS command happens
with respect to the search path that pg_dump will now be using at restore
time (ie, the schema the stats object is in, not that of the underlying
table). It's probably also significantly faster in the typical scenario
where only a minority of tables have extended stats.
Back-patch to v10 where extended stats were introduced.
Discussion: https://postgr.es/m/18272.1518328606@sss.pgh.pa.us
When CREATE INDEX is run on a partitioned table, create catalog entries
for an index on the partitioned table (which is just a placeholder since
the table proper has no data of its own), and recurse to create actual
indexes on the existing partitions; create them in future partitions
also.
As a convenience gadget, if the new index definition matches some
existing index in partitions, these are picked up and used instead of
creating new ones. Whichever way these indexes come about, they become
attached to the index on the parent table and are dropped alongside it,
and cannot be dropped on isolation unless they are detached first.
To support pg_dump'ing these indexes, add commands
CREATE INDEX ON ONLY <table>
(which creates the index on the parent partitioned table, without
recursing) and
ALTER INDEX ATTACH PARTITION
(which is used after the indexes have been created individually on each
partition, to attach them to the parent index). These reconstruct prior
database state exactly.
Reviewed-by: (in alphabetical order) Peter Eisentraut, Robert Haas, Amit
Langote, Jesper Pedersen, Simon Riggs, David Rowley
Discussion: https://postgr.es/m/20171113170646.gzweigyrgg6pwsg4@alvherre.pgsql
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources. The upper case spellings are only used
in some files/modules. So standardize on the standard spellings.
The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.
In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.
Reviewed-by: Michael Paquier <michael.paquier@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
This gets rid of the code that issued separate queries to retrieve the
partitioning parent-child relationship, parent partition key, and child
partition bound information. With this patch, the information is
retrieved instead using the queries issued from getTables() and
getInherits(), which is both more efficient than the previous approach
and doesn't require any new code.
Since the partitioning parent-child relationship is now retrieved with
the same old code that handles inheritance, partition attributes receive
a proper flagInhAttrs() treatment (that it didn't receive before), which
is needed so that the inherited NOT NULL constraints are not emitted if
we already emitted it for the parent.
Also, fix a bug in pg_dump's --binary-upgrade code, which caused pg_dump
to emit invalid command to attach a partition to its parent.
Author: Amit Langote, with some additional changes by me.
This is the SQL standard-conforming variant of PostgreSQL's serial
columns. It fixes a few usability issues that serial columns have:
- CREATE TABLE / LIKE copies default but refers to same sequence
- cannot add/drop serialness with ALTER TABLE
- dropping default does not drop sequence
- need to grant separate privileges to sequence
- other slight weirdnesses because serial is some kind of special macro
Reviewed-by: Vitaly Burovoy <vitaly.burovoy@gmail.com>
Add support for explicitly declared statistic objects (CREATE
STATISTICS), allowing collection of statistics on more complex
combinations that individual table columns. Companion commands DROP
STATISTICS and ALTER STATISTICS ... OWNER TO / SET SCHEMA / RENAME are
added too. All this DDL has been designed so that more statistic types
can be added later on, such as multivariate most-common-values and
multivariate histograms between columns of a single table, leaving room
for permitting columns on multiple tables, too, as well as expressions.
This commit only adds support for collection of n-distinct coefficient
on user-specified sets of columns in a single table. This is useful to
estimate number of distinct groups in GROUP BY and DISTINCT clauses;
estimation errors there can cause over-allocation of memory in hashed
aggregates, for instance, so it's a worthwhile problem to solve. A new
special pseudo-type pg_ndistinct is used.
(num-distinct estimation was deemed sufficiently useful by itself that
this is worthwhile even if no further statistic types are added
immediately; so much so that another version of essentially the same
functionality was submitted by Kyotaro Horiguchi:
https://postgr.es/m/20150828.173334.114731693.horiguchi.kyotaro@lab.ntt.co.jp
though this commit does not use that code.)
Author: Tomas Vondra. Some code rework by Álvaro.
Reviewed-by: Dean Rasheed, David Rowley, Kyotaro Horiguchi, Jeff Janes,
Ideriha Takeshi
Discussion: https://postgr.es/m/543AFA15.4080608@fuzzy.czhttps://postgr.es/m/20170320190220.ixlaueanxegqd5gr@alvherre.pgsql
In commit 23f34fa, we changed how ACLs were handled to use the new
pg_init_privs catalog and to dump out the ACL commands as REVOKE+GRANT
combinations instead of trying to REVOKE all rights always and then
GRANT back just the ones which were in place.
Unfortunately, the DEFAULT PRIVILEGES system didn't quite get the
correct treatment with this change and ended up (incorrectly) only
including positive GRANTs instead of both the REVOKEs and GRANTs
necessary to preserve the correct privileges.
There are only a couple cases where such REVOKEs are possible because,
generally speaking, there's few rights which exist on objects by
default to be revoked.
Examples of REVOKEs which weren't being correctly preserved are when
privileges are REVOKE'd from the creator/owner, like so:
ALTER DEFAULT PRIVILEGES
FOR ROLE myrole
REVOKE SELECT ON TABLES FROM myrole;
or when other default privileges are being revoked, such as EXECUTE
rights granted to public for functions:
ALTER DEFAULT PRIVILEGES
FOR ROLE myrole
REVOKE EXECUTE ON FUNCTIONS FROM PUBLIC;
Fix this by correctly working out what the correct REVOKE statements are
(if any) and dump them out, just as we do for everything else.
Noticed while developing additional regression tests for pg_dump, which
will be landing shortly.
Back-patch to 9.6 where the bug was introduced.
Table partitioning is like table inheritance and reuses much of the
existing infrastructure, but there are some important differences.
The parent is called a partitioned table and is always empty; it may
not have indexes or non-inherited constraints, since those make no
sense for a relation with no data of its own. The children are called
partitions and contain all of the actual data. Each partition has an
implicit partitioning constraint. Multiple inheritance is not
allowed, and partitioning and inheritance can't be mixed. Partitions
can't have extra columns and may not allow nulls unless the parent
does. Tuples inserted into the parent are automatically routed to the
correct partition, so tuple-routing ON INSERT triggers are not needed.
Tuple routing isn't yet supported for partitions which are foreign
tables, and it doesn't handle updates that cross partition boundaries.
Currently, tables can be range-partitioned or list-partitioned. List
partitioning is limited to a single column, but range partitioning can
involve multiple columns. A partitioning "column" can be an
expression.
Because table partitioning is less general than table inheritance, it
is hoped that it will be easier to reason about properties of
partitions, and therefore that this will serve as a better foundation
for a variety of possible optimizations, including query planner
optimizations. The tuple routing based which this patch does based on
the implicit partitioning constraints is an example of this, but it
seems likely that many other useful optimizations are also possible.
Amit Langote, reviewed and tested by Robert Haas, Ashutosh Bapat,
Amit Kapila, Rajkumar Raghuwanshi, Corey Huinker, Jaime Casanova,
Rushabh Lathia, Erik Rijkers, among others. Minor revisions by me.
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
pg_dump's traditional solution for breaking a circular dependency involving
a view was to create the view with CREATE TABLE and then later issue CREATE
RULE "_RETURN" ... to convert the table to a view, relying on the backend's
very very ancient code that supports making views that way. We've wanted
to get rid of that kluge for a long time, but the thing that finally
motivates doing something about it is the recognition that this method
fails with the --clean option, because it leads to issuing DROP RULE
"_RETURN" followed by DROP TABLE --- and the backend won't let you drop a
view's _RETURN rule.
Instead, let's break circular dependencies by initially creating the view
using CREATE VIEW AS SELECT NULL::columntype AS columnname, ... (so that
it has the right column names and types to support external references,
but no dependencies beyond the column data types), and then later dumping
the ON SELECT rule using the spelling CREATE OR REPLACE VIEW. This method
wasn't available when this code was originally written, but it's been
possible since PG 7.3, so it seems fine to start relying on it now.
To solve the --clean problem, make the dropStmt for an ON SELECT rule
be CREATE OR REPLACE VIEW with the same dummy target list as above.
In this way, during the DROP phase, we first reduce the view to have
no extra dependencies, and then we can drop it entirely when we've
gotten rid of whatever had a circular dependency on it.
(Note: this should work adequately well with the --if-exists option, since
the CREATE OR REPLACE VIEW will go through whether the view exists or not.
It could fail if the view exists with a conflicting column set, but we
don't really support --clean against a non-matching database anyway.)
This allows cleaning up some other kluges inside pg_dump, notably that
we don't need a notion of reloptions attached to a rule anymore.
Although this is a bug fix, commit to HEAD only for now. The problem's
existed for a long time and we've had relatively few complaints, so it
doesn't really seem worth taking risks to fix it in the back branches.
We might revisit that choice if no problems emerge.
Discussion: <19092.1479325184@sss.pgh.pa.us>
Instead of handling both sequence data and table data internally as
"table data", handle sequences separately under a "sequence set" type.
We already handled materialized view data differently, so it makes the
code somewhat cleaner to handle each relation kind separately at the top
level.
This does not change the output format, since there already was a
separate "SEQUENCE SET" archive entry type. A noticeable difference is
that SEQUENCE SET entries now always appear after TABLE DATA entries.
And in parallel mode there is less sorting to do, because the sequence
data entries are no longer considered table data.
Reviewed-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
The need for dumping from such ancient servers has decreased to about nil
in the field, so let's remove all the code that catered to it. Aside
from removing a lot of boilerplate variant queries, this allows us to not
have to cope with servers that don't have (a) schemas or (b) pg_depend.
That means we can get rid of assorted squishy code around that. There
may be some nonobvious additional simplifications possible, but this patch
already removes about 1500 lines of code.
I did not remove the ability for pg_restore to read custom-format archives
generated by these old versions (and light testing says that that does
still work). If you have an old server, you probably also have a pg_dump
that will work with it; but you have an old custom-format backup file,
that might be all you have.
It'd be possible at this point to remove fmtQualifiedId()'s version
argument, but I refrained since that would affect code outside pg_dump.
Discussion: <2661.1475849167@sss.pgh.pa.us>
Reviewing the cases where we need to LOCK a given table during a dump,
it was pointed out by Tom that we really don't need to LOCK a table if
we are only looking to dump the ACL for it, or certain other
components. After reviewing the queries run for all of the component
pieces, a list of components were determined to not require LOCK'ing
of the table.
This implements a check to avoid LOCK'ing those tables.
Initial complaint from Rushabh Lathia, discussed with Robert and Tom,
the patch is mine.
Now indexes (but only B-tree for now) can contain "extra" column(s) which
doesn't participate in index structure, they are just stored in leaf
tuples. It allows to use index only scan by using single index instead
of two or more indexes.
Author: Anastasia Lubennikova with minor editorializing by me
Reviewers: David Rowley, Peter Geoghegan, Jeff Janes
Now that all of the infrastructure exists, add in the ability to
dump out the ACLs of the objects inside of pg_catalog or the ACLs
for objects which are members of extensions, but only if they have
been changed from their original values.
The original values are tracked in pg_init_privs. When pg_dump'ing
9.6-and-above databases, we will dump out the ACLs for all objects
in pg_catalog and the ACLs for all extension members, where the ACL
has been changed from the original value which was set during either
initdb or CREATE EXTENSION.
This should not change dumps against pre-9.6 databases.
Reviews by Alexander Korotkov, Jose Luis Tallon
Historically, the "dump" component of the namespace has been used
to decide if the objects inside of the namespace should be dumped
also. Given that "dump" is now a bitmask and may be partial, and
we may want to dump out all components of the namespace object but
only some of the components of objects contained in the namespace,
create a "dump_contains" bitmask which will represent what components
of the objects inside of a namespace should be dumped out.
No behavior change here, but in preparation for a change where we
will dump out just the ACLs of objects in pg_catalog, but we might
not dump out the ACL of the pg_catalog namespace itself (for instance,
when it hasn't been changed from the value set at initdb time).
Reviews by Alexander Korotkov, Jose Luis Tallon
pg_dump has historically used a simple boolean 'dump' value to indicate
if a given object should be included in the dump or not. Instead, use
a bitmap which breaks down the components of an object into their
distinct pieces and use that bitmap to only include the components
requested.
This does not include any behavioral change, but is in preperation for
the change to dump out just ACLs for objects in pg_catalog.
Reviews by Alexander Korotkov, Jose Luis Tallon
Per discussion, we want to create a static library and put the stuff into
it that until now has been shared across src/bin/ directories by ad-hoc
methods like symlinking a source file. This commit creates the library and
populates it with a couple of files that contain the widely-useful portions
of pg_dump's dumputils.c file. dumputils.c survives, because it has some
stuff that didn't seem appropriate for fe_utils, but it's significantly
smaller and is no longer referenced from any other directory.
Follow-on patches will move more stuff into fe_utils.
The Mkvcbuild.pm hacking here is just a best guess; we'll see how the
buildfarm likes it.
This enables external code to create access methods. This is useful so
that extensions can add their own access methods which can be formally
tracked for dependencies, so that DROP operates correctly. Also, having
explicit support makes pg_dump work correctly.
Currently only index AMs are supported, but we expect different types to
be added in the future.
Authors: Alexander Korotkov, Petr Jelínek
Reviewed-By: Teodor Sigaev, Petr Jelínek, Jim Nasby
Commitfest-URL: https://commitfest.postgresql.org/9/353/
Discussion: https://www.postgresql.org/message-id/CAPpHfdsXwZmojm6Dx+TJnpYk27kT4o7Ri6X_4OSWcByu1Rm+VA@mail.gmail.com
If a view is split into CREATE TABLE + CREATE RULE to break a circular
dependency, then any triggers on the view must be dumped/reloaded after
the CREATE RULE; else the backend may reject the CREATE TRIGGER because
it's the wrong type of trigger for a plain table. This works all right
in plain dump/restore because of pg_dump's sorting heuristic that places
triggers after rules. However, when using parallel restore, the ordering
must be enforced by a dependency --- and we didn't have one.
Fixing this is a mere matter of adding an addObjectDependency() call,
except that we need to be able to find all the triggers belonging to the
view relation, and there was no easy way to do that. Add fields to
pg_dump's TableInfo struct to remember where the associated TriggerInfo
struct(s) are.
Per bug report from Dennis Kögel. The failure can be exhibited at least
as far back as 9.1, so back-patch to all supported branches.
pg_dump's original approach to handling extension member objects was to
run around and clear (or set) their dump flags rather late in its data
collection process. Unfortunately, quite a lot of code expects those flags
to be valid before that; which was an entirely reasonable expectation
before we added extensions. In particular, this explains Karsten Hilbert's
recent report of pg_upgrade failing on a database in which an extension
has been installed into the pg_catalog schema. Its objects are initially
marked as not-to-be-dumped on the strength of their schema, and later we
change them to must-dump because we're doing a binary upgrade of their
extension; but we've already skipped essential tasks like making associated
DO_SHELL_TYPE objects.
To fix, collect extension membership data first, and incorporate it in the
initial setting of the dump flags, so that those are once again correct
from the get-go. This has the undesirable side effect of slightly
lengthening the time taken before pg_dump acquires table locks, but testing
suggests that the increase in that window is not very much.
Along the way, get rid of ugly special-case logic for deciding whether
to dump procedural languages, FDWs, and foreign servers; dump decisions
for those are now correct up-front, too.
In 9.3 and up, this also fixes erroneous logic about when to dump event
triggers (basically, they were *always* dumped before). In 9.5 and up,
transform objects had that problem too.
Since this problem came in with extensions, back-patch to all supported
versions.
Rather than passing around DumpOptions and RestoreOptions as separate
arguments, add fields to struct Archive to carry pointers to these objects,
and access them through those fields when needed. There already was a
RestoreOptions pointer in Archive, though for no obvious reason it was part
of the "private" struct rather than out where pg_dump.c could see it.
Doing this allows reversion of quite a lot of parameter-addition changes
made in commit 0eea8047bf, which is a good thing IMO because this will
reduce the code delta between 9.4 and 9.5, probably easing a few future
back-patch efforts. Moreover, the previous commit only added a DumpOptions
argument to functions that had to have it at the time, which means we could
anticipate still more code churn (and more back-patch hazard) as the
requirement spread further. I'd hit exactly that problem in my upcoming
patch to fix extension membership marking, which is what motivated me to
do this.
Commit c7e27becd2 fixed this on the backend side, but we neglected
the fact that several code paths in pg_dump were printing reloptions
values that had not gotten massaged by ruleutils. Apply essentially the
same quoting logic in those places, too.
To allow users to force RLS to always be applied, even for table owners,
add ALTER TABLE .. FORCE ROW LEVEL SECURITY.
row_security=off overrides FORCE ROW LEVEL SECURITY, to ensure pg_dump
output is complete (by default).
Also add SECURITY_NOFORCE_RLS context to avoid data corruption when
ALTER TABLE .. FORCE ROW SECURITY is being used. The
SECURITY_NOFORCE_RLS security context is used only during referential
integrity checks and is only considered in check_enable_rls() after we
have already checked that the current user is the owner of the relation
(which should always be the case during referential integrity checks).
Back-patch to 9.5 where RLS was added.
Mistakenly relreplident was stored as a bool. That works today as c.h
typedefs bool to a char, but isn't very future proof.
Discussion: 20150812084351.GD8470@awork2.anarazel.de
Backpatch: 9.4 where replica identity was introduced.
Per discussion, it really ought to do this. The original choice to
exclude shell types was probably made in the dark ages before we made
it harder to accidentally create shell types; but that was in 7.3.
Also, cause the standard regression tests to leave a shell type behind,
for convenience in testing the case in pg_dump and pg_upgrade.
Back-patch to all supported branches.
This provides a mechanism for specifying conversions between SQL data
types and procedural languages. As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.
reviews by Pavel Stěhule and Andres Freund
Commit 7b583b20b1 created an unnecessary
dump failure hazard by applying pg_get_function_identity_arguments()
to every function in the database, even those that won't get dumped.
This could result in snapshot-related problems if concurrent sessions are,
for example, creating and dropping temporary functions, as noted by Marko
Tiikkaja in bug #12832. While this is by no means pg_dump's only such
issue with concurrent DDL, it's unfortunate that we added a new failure
mode for cases that used to work, and even more so that the failure was
created for basically cosmetic reasons (ie, to sort overloaded functions
more deterministically).
To fix, revert that patch and instead sort function arguments using
information that pg_dump has available anyway, namely the names of the
argument types. This will produce a slightly different sort ordering for
overloaded functions than the previous coding; but applying strcmp
directly to the output of pg_get_function_identity_arguments really was
a bit odd anyway. The sorting will still be name-based and hence
independent of possibly-installation-specific OID assignments. A small
additional benefit is that sorting now works regardless of server version.
Back-patch to 9.3, where the previous commit appeared.
Back in 2003 we had a discussion about how to decide which casts to dump.
At the time pg_dump really only considered an object's containing schema
to decide what to dump (ie, dump whatever's not in pg_catalog), and so
we chose a complicated idea involving whether the underlying types were to
be dumped (cf commit a6790ce857). But users
are allowed to create casts between built-in types, and we failed to dump
such casts. Let's get rid of that heuristic, which has accreted even more
ugliness since then, in favor of just looking at the cast's OID to decide
if it's a built-in cast or not.
In passing, also fix some really ancient code that supposed that it had to
manufacture a dependency for the cast on its cast function; that's only
true when dumping from a pre-7.3 server. This just resulted in some wasted
cycles and duplicate dependency-list entries with newer servers, but we
might as well improve it.
Per gripes from a number of people, most recently Greg Sabino Mullane.
Back-patch to all supported branches.
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!
Most pg_dump.c global variables, which were passed down individually to
dumping routines, are now grouped as members of the new DumpOptions
struct, which is used as a local variable and passed down into routines
that need it. This helps future development efforts; in particular it
is said to enable a mode in which a parallel pg_dump run can output
multiple streams, and have them restored in parallel.
Also take the opportunity to clean up the pg_dump header files somewhat,
to avoid circularity.
Author: Joachim Wieland, revised by Álvaro Herrera
Reviewed by Peter Eisentraut
Andres pointed out that there was an extra ';' in equalPolicies, which
made me realize that my prior testing with CLOBBER_CACHE_ALWAYS was
insufficient (it didn't always catch the issue, just most of the time).
Thanks to that, a different issue was discovered, specifically in
equalRSDescs. This change corrects eqaulRSDescs to return 'true' once
all policies have been confirmed logically identical. After stepping
through both functions to ensure correct behavior, I ran this for
about 12 hours of CLOBBER_CACHE_ALWAYS runs of the regression tests
with no failures.
In addition, correct a few typos in the documentation which were pointed
out by Thom Brown (thanks!) and improve the policy documentation further
by adding a flushed out usage example based on a unix passwd file.
Lastly, clean up a few comments in the regression tests and pg_dump.h.
Buildfarm member tick identified an issue where the policies in the
relcache for a relation were were being replaced underneath a running
query, leading to segfaults while processing the policies to be added
to a query. Similar to how TupleDesc RuleLocks are handled, add in a
equalRSDesc() function to check if the policies have actually changed
and, if not, swap back the rsdesc field (using the original instead of
the temporairly built one; the whole structure is swapped and then
specific fields swapped back). This now passes a CLOBBER_CACHE_ALWAYS
for me and should resolve the buildfarm error.
In addition to addressing this, add a new chapter in Data Definition
under Privileges which explains row security and provides examples of
its usage, change \d to always list policies (even if row security is
disabled- but note that it is disabled, or enabled with no policies),
rework check_role_for_policy (it really didn't need the entire policy,
but it did need to be using has_privs_of_role()), and change the field
in pg_class to relrowsecurity from relhasrowsecurity, based on
Heikki's suggestion. Also from Heikki, only issue SET ROW_SECURITY in
pg_restore when talking to a 9.5+ server, list Bypass RLS in \du, and
document --enable-row-security options for pg_dump and pg_restore.
Lastly, fix a number of minor whitespace and typo issues from Heikki,
Dimitri, add a missing #include, per Peter E, fix a few minor
variable-assigned-but-not-used and resource leak issues from Coverity
and add tab completion for role attribute bypassrls as well.
Building on the updatable security-barrier views work, add the
ability to define policies on tables to limit the set of rows
which are returned from a query and which are allowed to be added
to a table. Expressions defined by the policy for filtering are
added to the security barrier quals of the query, while expressions
defined to check records being added to a table are added to the
with-check options of the query.
New top-level commands are CREATE/ALTER/DROP POLICY and are
controlled by the table owner. Row Security is able to be enabled
and disabled by the owner on a per-table basis using
ALTER TABLE .. ENABLE/DISABLE ROW SECURITY.
Per discussion, ROW SECURITY is disabled on tables by default and
must be enabled for policies on the table to be used. If no
policies exist on a table with ROW SECURITY enabled, a default-deny
policy is used and no records will be visible.
By default, row security is applied at all times except for the
table owner and the superuser. A new GUC, row_security, is added
which can be set to ON, OFF, or FORCE. When set to FORCE, row
security will be applied even for the table owner and superusers.
When set to OFF, row security will be disabled when allowed and an
error will be thrown if the user does not have rights to bypass row
security.
Per discussion, pg_dump sets row_security = OFF by default to ensure
that exports and backups will have all data in the table or will
error if there are insufficient privileges to bypass row security.
A new option has been added to pg_dump, --enable-row-security, to
ask pg_dump to export with row security enabled.
A new role capability, BYPASSRLS, which can only be set by the
superuser, is added to allow other users to be able to bypass row
security using row_security = OFF.
Many thanks to the various individuals who have helped with the
design, particularly Robert Haas for his feedback.
Authors include Craig Ringer, KaiGai Kohei, Adam Brightwell, Dean
Rasheed, with additional changes and rework by me.
Reviewers have included all of the above, Greg Smith,
Jeff McCormick, and Robert Haas.
Peter Eisentraut
Tom Lane
Alvaro Herrera
Bruce Momjian
Stephen Frost
Robert Haas
Teodor Sigaev
Andres Freund