The previous functions of assign hooks are now split between check hooks
and assign hooks, where the former can fail but the latter shouldn't.
Aside from being conceptually clearer, this approach exposes the
"canonicalized" form of the variable value to guc.c without having to do
an actual assignment. And that lets us fix the problem recently noted by
Bernd Helmle that the auto-tune patch for wal_buffers resulted in bogus
log messages about "parameter "wal_buffers" cannot be changed without
restarting the server". There may be some speed advantage too, because
this design lets hook functions avoid re-parsing variable values when
restoring a previous state after a rollback (they can store a pre-parsed
representation of the value instead). This patch also resolves a
longstanding annoyance about custom error messages from variable assign
hooks: they should modify, not appear separately from, guc.c's own message
about "invalid parameter value".
Use collencoding = -1 to represent such a collation in pg_collation.
We need this to make the "default" entry work sanely, and a later
patch will fix the C/POSIX entries to be represented this way instead
of duplicating them across all encodings. All lookup operations now
search first for an entry that's database-encoding-specific, and then
for the same name with collencoding = -1.
Also some incidental code cleanup in collationcmds.c and pg_collation.c.
This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.
Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
This commit replaces pg_class.relistemp with pg_class.relpersistence;
and also modifies the RangeVar node type to carry relpersistence rather
than istemp. It also removes removes rd_istemp from RelationData and
instead performs the correct computation based on relpersistence.
For clarity, we add three new macros: RelationNeedsWAL(),
RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we
can clarify the purpose of each check that previous depended on
rd_istemp.
This is intended as infrastructure for the upcoming unlogged tables
patch, as well as for future possible work on global temporary tables.
Any flavor of ALTER <whatever> .. SET SCHEMA fails if (1) the object
is already in the new schema, (2) either the old or new schema is
a temp schema, or (3) either the old or new schema is the TOAST schema.
Extraced from a patch by Dimitri Fontaine, with additional hacking by me.
This allows us to reliably remove all leftover temporary relation
files on cluster startup without reference to system catalogs or WAL;
therefore, we no longer include temporary relations in XLOG_XACT_COMMIT
and XLOG_XACT_ABORT WAL records.
Since these changes require including a backend ID in each
SharedInvalSmgrMsg, the size of the SharedInvalidationMessage.id
field has been reduced from two bytes to one, and the maximum number
of connections has been reduced from INT_MAX / 4 to 2^23-1. It would
be possible to remove these restrictions by increasing the size of
SharedInvalidationMessage by 4 bytes, but right now that doesn't seem
like a good trade-off.
Review by Jaime Casanova and Tom Lane.
path that specifies useTemp, but there is no active temp schema in the
current session. (This can happen if the path was saved during a transaction
that created a temp schema and was later rolled back.) For existing callers
it's sufficient to ignore the useTemp flag in this case, though we might
later want to offer an option to create a fresh temp schema. So far as I can
tell this is just an Assert failure: in a non-assert build, the code would
push a zero onto the new search path, which is useless but not very harmful.
Per bug report from Heikki.
Back-patch to 8.3; prior versions don't have this code.
- Rename TSParserGetPrsid to get_ts_parser_oid.
- Rename TSDictionaryGetDictid to get_ts_dict_oid.
- Rename TSTemplateGetTmplid to get_ts_template_oid.
- Rename TSConfigGetCfgid to get_ts_config_oid.
- Rename FindConversionByName to get_conversion_oid.
- Rename GetConstraintName to get_constraint_oid.
- Add new functions get_opclass_oid, get_opfamily_oid, get_rewrite_oid,
get_rewrite_oid_without_relid, get_trigger_oid, and get_cast_oid.
The name of each function matches the corresponding catalog.
Thanks to KaiGai Kohei for the review.
unqualified names.
- Add a missing_ok parameter to get_tablespace_oid.
- Avoid duplicating get_tablespace_od guts in objectNamesToOids.
- Add a missing_ok parameter to get_database_oid.
- Replace get_roleid and get_role_checked with get_role_oid.
- Add get_namespace_oid, get_language_oid, get_am_oid.
- Refactor existing code to use new interfaces.
Thanks to KaiGai Kohei for the review.
Add some checks that seem logically necessary, in particular let's make
real sure that HS slave sessions cannot create temp tables. (If they did
they would think that temp tables belonging to the master's session with
the same BackendId were theirs. We *must* not allow myTempNamespace to
become set in a slave session.)
Change setval() and nextval() so that they are only allowed on temp sequences
in a read-only transaction. This seems consistent with what we allow for
table modifications in read-only transactions. Since an HS slave can't have a
temp sequence, this also provides a nicer cure for the setval PANIC reported
by Erik Rijkers.
Make the error messages more uniform, and have them mention the specific
command being complained of. This seems worth the trifling amount of extra
code, since people are likely to see such messages a lot more than before.
The purpose of this change is to eliminate the need for every caller
of SearchSysCache, SearchSysCacheCopy, SearchSysCacheExists,
GetSysCacheOid, and SearchSysCacheList to know the maximum number
of allowable keys for a syscache entry (currently 4). This will
make it far easier to increase the maximum number of keys in a
future release should we choose to do so, and it makes the code
shorter, too.
Design and review by Tom Lane.
All callers of FindConversionByName() already do suitable permissions
checking already apart from this function, but this is not just dead
code removal: the unnecessary permissions check can actually lead to
spurious failures - there's no reason why inability to execute the
underlying function should prohibit renaming the conversion, for example.
(The error messages in these cases were also rather poor:
FindConversion would return InvalidOid, eventually leading to a complaint
that the conversion "did not exist", which was not correct.)
KaiGai Kohei
recent proposal. As proof of concept, remove knowledge of Params from the
core parser, arranging for them to be handled entirely by parser hook
functions. It turns out we need an additional hook for that --- I had
forgotten about the code that handles inferring a parameter's type from
context.
This is a preliminary step towards letting plpgsql handle its variables
through parser hooks. Additional work remains to be done to expose the
facility through SPI, but I think this is all the changes needed in the core
parser.
temp relations; this is no more expensive than before, now that we have
pg_class.relistemp. Insert tests into bufmgr.c to prevent attempting
to fetch pages from nonlocal temp relations. This provides a low-level
defense against bugs-of-omission allowing temp pages to be loaded into shared
buffers, as in the contrib/pgstattuple problem reported by Stuart Bishop.
While at it, tweak a bunch of places to use new relcache tests (instead of
expensive probes into pg_namespace) to detect local or nonlocal temp tables.
to return NULL, instead of erroring out, if the target object is specified by
OID and we can't find that OID in the catalogs. Since these functions operate
internally on SnapshotNow rules, there is a race condition when using them
in user queries: the query's MVCC snapshot might "see" a catalog row that's
already committed dead, leading to a failure when the inquiry function is
applied. Returning NULL should generally provide more convenient behavior.
This issue has been complained of before, and in particular we are now seeing
it in the regression tests due to another recent patch.
when user-defined functions used in a plan are modified. Also invalidate
plans when schemas, operators, or operator classes are modified; but for these
cases we just invalidate everything rather than tracking exact dependencies,
since these types of objects seldom change in a production database.
Tom Lane; loosely based on a patch by Martin Pihlak.
SELECT foo.*) so that it cannot be confused with a quoted identifier "*".
Instead create a separate node type A_Star to represent this notation.
Per pgsql-hackers discussion of 2007-Sep-27.
need to deconstruct proargmodes for each pg_proc entry inspected by
FuncnameGetCandidates(). Fixes function lookup performance regression
caused by yesterday's variadic-functions patch.
In passing, make pg_proc.probin be NULL, rather than a dummy value '-',
in cases where it is not actually used for the particular type of function.
This should buy back some of the space cost of the extra column.
so long as all the trailing arguments are of the same (non-array) type.
The function receives them as a single array argument (which is why they
have to all be the same type).
It might be useful to extend this facility to aggregates, but this patch
doesn't do that.
This patch imposes a noticeable slowdown on function lookup --- a follow-on
patch will fix that by adding a redundant column to pg_proc.
Pavel Stehule
backend. If so, send a LOG message to the postmaster log, and if the table
is beyond the vacuum-for-wraparound horizon, forcibly drop it. Per recent
discussions. Perhaps we ought to back-patch this, but it probably needs
to age a bit in HEAD first.
corresponding struct definitions. This allows other headers to avoid including
certain highly-loaded headers such as rel.h and relscan.h, instead using just
relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less
unnecessary dependencies.
inclusions in src/include/catalog/*.h files. The main idea here is to push
function declarations for src/backend/catalog/*.c files into separate headers,
rather than sticking them into the corresponding catalog definition file as
has been done in the past. This commit only carries out that idea fully for
pg_proc, pg_type and pg_conversion, but that's enough for the moment ---
if pg_list.h ever becomes unsafe for frontend code to include, we'll need
to work a bit more.
Zdenek Kotala
by short-circuiting schema search path and ambiguous-operator resolution
computations. Remarkably, this buys as much as 45% speedup of repetitive
simple queries that involve operators that are not an exact match to the
input datatypes. It should be marginally faster even for exact-match
cases, though I've not had success in proving an improvement in benchmark
tests. Per report from Guillame Smet and subsequent discussion.
namespace isn't necessarily first in the search path (there could be implicit
schemas ahead of it). Examples are
test=# set search_path TO s1;
test=# create view pg_timezone_names as select * from pg_timezone_names();
ERROR: "pg_timezone_names" is already a view
test=# create table pg_class (f1 int primary key);
ERROR: permission denied: "pg_class" is a system catalog
You'd expect these commands to create the requested objects in s1, since
names beginning with pg_ aren't supposed to be reserved anymore. What is
happening is that we create the requested base table and then execute
additional commands (here, CREATE RULE or CREATE INDEX), and that code is
passed the same RangeVar that was in the original command. Since that
RangeVar has schemaname = NULL, the secondary commands think they should do a
path search, and that means they find system catalogs that are implicitly in
front of s1 in the search path.
This is perilously close to being a security hole: if the secondary command
failed to apply a permission check then it'd be possible for unprivileged
users to make schema modifications to system catalogs. But as far as I can
find, there is no code path in which a check doesn't occur. Which makes it
just a weird corner-case bug for people who are silly enough to want to
name their tables the same as a system catalog.
The relevant code has changed quite a bit since 8.2, which means this patch
wouldn't work as-is in the back branches. Since it's a corner case no one
has reported from the field, I'm not going to bother trying to back-patch.
Oleg Bartunov and Teodor Sigaev, but I did a lot of editorializing,
so anything that's broken is probably my fault.
Documentation is nonexistent as yet, but let's land the patch so we can
get some portability testing done.
named pg_toast_temp_nnn, alongside the pg_temp_nnn schemas used for the temp
tables themselves. This allows low-level code such as the relcache to
recognize that these tables are indeed temporary, which enables various
optimizations such as not WAL-logging changes and using local rather than
shared buffers for access. Aside from obvious performance benefits, this
provides a solution to bug #3483, in which other backends unexpectedly held
open file references to temporary tables. The scheme preserves the property
that TOAST tables are not in any schema that's normally in the search path,
so they don't conflict with user table names.
initdb forced because of changes in system view definitions.
This is needed to allow a security-definer function to set a truly secure
value of search_path. Without it, a malicious user can use temporary objects
to execute code with the privileges of the security-definer function. Even
pushing the temp schema to the back of the search path is not quite good
enough, because a function or operator at the back of the path might still
capture control from one nearer the front due to having a more exact datatype
match. Hence, disable searching the temp schema altogether for functions and
operators.
Security: CVE-2007-2138
reviewed by Neil Conway. This patch adds the following DDL command
variants: RESET SESSION, RESET TEMP, RESET PLANS, CLOSE ALL, and
DEALLOCATE ALL. RESET SESSION is intended for use by connection
pool software and the like, in order to reset a client session
to something close to its initial state.
Note that while most of these command variants can be executed
inside a transaction block (but are not transaction-aware!),
RESET SESSION cannot. While this is inconsistent, it is intended
to catch programmer mistakes: RESET SESSION in an open transaction
block is probably unintended.
search_path that was active when the plan was first made. To do this,
improve namespace.c to support a stack of "override" search path settings
(we must have a stack since nested replan events are entirely possible).
This facility replaces the "special namespace" hack formerly used by
CREATE SCHEMA, and should be able to support per-function search path
settings as well.
equality checks it applies, instead of a random dependence on whatever
operators might be named "=". The equality operators will now be selected
from the opfamily of the unique index that the FK constraint depends on to
enforce uniqueness of the referenced columns; therefore they are certain to be
consistent with that index's notion of equality. Among other things this
should fix the problem noted awhile back that pg_dump may fail for foreign-key
constraints on user-defined types when the required operators aren't in the
search path. This also means that the former warning condition about "foreign
key constraint will require costly sequential scans" is gone: if the
comparison condition isn't indexable then we'll reject the constraint
entirely. All per past discussions.
Along the way, make the RI triggers look into pg_constraint for their
information, instead of using pg_trigger.tgargs; and get rid of the always
error-prone fixed-size string buffers in ri_triggers.c in favor of building up
the RI queries in StringInfo buffers.
initdb forced due to columns added to pg_constraint and pg_trigger.
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
cases. Operator classes now exist within "operator families". While most
families are equivalent to a single class, related classes can be grouped
into one family to represent the fact that they are semantically compatible.
Cross-type operators are now naturally adjunct parts of a family, without
having to wedge them into a particular opclass as we had done originally.
This commit restructures the catalogs and cleans up enough of the fallout so
that everything still works at least as well as before, but most of the work
needed to actually improve the planner's behavior will come later. Also,
there are not yet CREATE/DROP/ALTER OPERATOR FAMILY commands; the only way
to create a new family right now is to allow CREATE OPERATOR CLASS to make
one by default. I owe some more documentation work, too. But that can all
be done in smaller pieces once this infrastructure is in place.
Bruce Momjian
Tom Lane
Peter Eisentraut
Robert Haas
Magnus Hagander
Alvaro Herrera
Neil Conway