Commit Graph

1425 Commits

Author SHA1 Message Date
50533a6dc5 Support comments on FOREIGN DATA WRAPPER and SERVER objects.
This mostly involves making it work with the objectaddress.c framework,
which does most of the heavy lifting.  In that vein, change
GetForeignDataWrapperOidByName to get_foreign_data_wrapper_oid and
GetForeignServerOidByName to get_foreign_server_oid, to match the
pattern we use for other object types.

Robert Haas and Shigeru Hanada
2011-04-01 11:28:28 -04:00
b23c9fa929 Clean up a few failures to set collation fields in expression nodes.
I'm not sure these have any non-cosmetic implications, but I'm not sure
they don't, either.  In particular, ensure the CaseTestExpr generated
by transformAssignmentIndirection to represent the base target column
carries the correct collation, because parse_collate.c won't fix that.
Tweak lsyscache.c API so that we can get the appropriate collation
without an extra syscache lookup.
2011-03-26 14:25:48 -04:00
b051a34fd8 Remove duplicate time-based macros recently added. 2011-03-14 10:40:14 -04:00
696d1f7f06 Make all comparisons done for/with statistics use the default collation.
While this will give wrong answers when estimating selectivity for a
comparison operator that's using a non-default collation, the estimation
error probably won't be large; and anyway the former approach created
estimation errors of its own by trying to use a histogram that might have
been computed with some other collation.  So we'll adopt this simplified
approach for now and perhaps improve it sometime in the future.

This patch incorporates changes from Andres Freund to make sure that
selfuncs.c passes a valid collation OID to any datatype-specific function
it calls, in case that function wants collation information.  Said OID will
now always be DEFAULT_COLLATION_OID, but at least we won't get errors.
2011-03-12 16:30:36 -05:00
3a3f39fdc0 Use macros for time-based constants, rather than constants. 2011-03-12 09:35:56 -05:00
49a08ca1e9 Adjust the permissions required for COMMENT ON ROLE.
Formerly, any member of a role could change the role's comment, as of
course could superusers; but holders of CREATEROLE privilege could not,
unless they were also members.  This led to the odd situation that a
CREATEROLE holder could create a role but then could not comment on it.
It also seems a bit dubious to let an unprivileged user change his own
comment, let alone those of group roles he belongs to.  So, change the
rule to be "you must be superuser to comment on a superuser role, or
hold CREATEROLE to comment on non-superuser roles".  This is the same
as the privilege check for creating/dropping roles, and thus fits much
better with the rule for other object types, namely that only the owner
of an object can comment on it.

In passing, clean up the documentation for COMMENT a little bit.

Per complaint from Owen Jacobson and subsequent discussion.
2011-03-09 11:28:34 -05:00
8d3b421f5f Allow non-superusers to create (some) extensions.
Remove the unconditional superuser permissions check in CREATE EXTENSION,
and instead define a "superuser" extension property, which when false
(not the default) skips the superuser permissions check.  In this case
the calling user only needs enough permissions to execute the commands
in the extension's installation script.  The superuser property is also
enforced in the same way for ALTER EXTENSION UPDATE cases.

In other ALTER EXTENSION cases and DROP EXTENSION, test ownership of
the extension rather than superuserness.  ALTER EXTENSION ADD/DROP needs
to insist on ownership of the target object as well; to do that without
duplicating code, refactor comment.c's big switch for permissions checks
into a separate function in objectaddress.c.

I also removed the superuserness checks in pg_available_extensions and
related functions; there's no strong reason why everybody shouldn't
be able to see that info.

Also invent an IF NOT EXISTS variant of CREATE EXTENSION, and use that
in pg_dump, so that dumps won't fail for installed-by-default extensions.
We don't have any of those yet, but we will soon.

This is all per discussion of wrapping the standard procedural languages
into extensions.  I'll make those changes in a separate commit; this is
just putting the core infrastructure in place.
2011-03-04 16:08:53 -05:00
6252c4f9e2 Run a portal's cleanup hook immediately when pushing it to DONE state.
This works around the problem noted by Yamamoto Takashi in bug #5906,
that there were code paths whereby we could reach AtCleanup_Portals
with a portal's cleanup hook still unexecuted.  The changes I made
a few days ago were intended to prevent that from happening, and
I think that on balance it's still a good thing to avoid, so I don't
want to remove the Assert in AtCleanup_Portals.  Hence do this instead.
2011-03-03 13:04:06 -05:00
c0b0076036 Rearrange snapshot handling to make rule expansion more consistent.
With this patch, portals, SQL functions, and SPI all agree that there
should be only a CommandCounterIncrement between the queries that are
generated from a single SQL command by rule expansion.  Fetching a whole
new snapshot now happens only between original queries.  This is equivalent
to the existing behavior of EXPLAIN ANALYZE, and it was judged to be the
best choice since it eliminates one source of concurrency hazards for
rules.  The patch should also make things marginally faster by reducing the
number of snapshot push/pop operations.

The patch removes pg_parse_and_rewrite(), which is no longer used anywhere.
There was considerable discussion about more aggressive refactoring of the
query-processing functions exported by postgres.c, but for the moment
nothing more has been done there.

I also took the opportunity to refactor snapmgr.c's API slightly: the
former PushUpdatedSnapshot() has been split into two functions.

Marko Tiikkaja, reviewed by Steve Singer and Tom Lane
2011-02-28 23:28:06 -05:00
a874fe7b4c Refactor the executor's API to support data-modifying CTEs better.
The originally committed patch for modifying CTEs didn't interact well
with EXPLAIN, as noted by myself, and also had corner-case problems with
triggers, as noted by Dean Rasheed.  Those problems show it is really not
practical for ExecutorEnd to call any user-defined code; so split the
cleanup duties out into a new function ExecutorFinish, which must be called
between the last ExecutorRun call and ExecutorEnd.  Some Asserts have been
added to these functions to help verify correct usage.

It is no longer necessary for callers of the executor to call
AfterTriggerBeginQuery/AfterTriggerEndQuery for themselves, as this is now
done by ExecutorStart/ExecutorFinish respectively.  If you really need to
suppress that and do it for yourself, pass EXEC_FLAG_SKIP_TRIGGERS to
ExecutorStart.

Also, refactor portal commit processing to allow for the possibility that
PortalDrop will invoke user-defined code.  I think this is not actually
necessary just yet, since the portal-execution-strategy logic forces any
non-pure-SELECT query to be run to completion before we will consider
committing.  But it seems like good future-proofing.
2011-02-27 13:44:12 -05:00
389af95155 Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH.
This patch implements data-modifying WITH queries according to the
semantics that the updates all happen with the same command counter value,
and in an unspecified order.  Therefore one WITH clause can't see the
effects of another, nor can the outer query see the effects other than
through the RETURNING values.  And attempts to do conflicting updates will
have unpredictable results.  We'll need to document all that.

This commit just fixes the code; documentation updates are waiting on
author.

Marko Tiikkaja and Hitoshi Harada
2011-02-25 18:58:02 -05:00
1c51c7d5ff Add PL/Python functions for quoting strings
Add functions plpy.quote_ident, plpy.quote_literal,
plpy.quote_nullable, which wrap the equivalent SQL functions.

To be able to propagate char * constness properly, make the argument
of quote_literal_cstr() const char *.  This also makes it more
consistent with quote_identifier().

Jan Urbański, reviewed by Hitoshi Harada, some refinements by Peter
Eisentraut
2011-02-22 23:41:23 +02:00
1ab9b012bd Allow binary I/O of type "void".
void_send is useful for the same reason that void_out doesn't throw error,
namely that someone might do "select void_returning_func(...)"  from a
client that prefers to operate in binary mode.  The void_recv function may
or may not have any practical use, but we provide it for symmetry.

Radosław Smogura
2011-02-22 13:08:22 -05:00
327e025071 Create the catalog infrastructure for foreign-data-wrapper handlers.
Add a fdwhandler column to pg_foreign_data_wrapper, plus HANDLER options
in the CREATE FOREIGN DATA WRAPPER and ALTER FOREIGN DATA WRAPPER commands,
plus pg_dump support for same.  Also invent a new pseudotype fdw_handler
with properties similar to language_handler.

This is split out of the "FDW API" patch for ease of review; it's all stuff
we will certainly need, regardless of any other details of the FDW API.
FDW handler functions will not actually get called yet.

In passing, fix some omissions and infelicities in foreigncmds.c.

Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
2011-02-19 00:07:15 -05:00
62c7bd31c8 Add transaction-level advisory locks.
They share the same locking namespace with the existing session-level
advisory locks, but they are automatically released at the end of the
current transaction and cannot be released explicitly via unlock
functions.

Marko Tiikkaja, reviewed by me.
2011-02-18 14:05:12 +09:00
6595dd04d1 Add backwards-compatible declarations of some core GIN support functions.
These are needed to support reloading dumps of 9.0 installations containing
contrib/intarray or contrib/tsearch2.  Since not only regular dump/reload
but binary upgrade would fail, it seems worth the trouble to carry these
stubs for awhile.  Note that the contrib opclasses referencing these
functions will still work fine, since GIN doesn't actually pay any
attention to the declared signature of a support function.
2011-02-16 17:24:46 -05:00
6e02755b22 Add FOREACH IN ARRAY looping to plpgsql.
(I'm not entirely sure that we've finished bikeshedding the syntax details,
but the functionality seems OK.)

Pavel Stehule, reviewed by Stephen Frost and Tom Lane
2011-02-16 01:53:03 -05:00
887dd041a6 Fix obsolete comment.
Comment about MaxAllocSize was not updated when the TOAST-header macros
were replaced in 8.3 "varvarlena" changes.  Per report from Frederik Ramm.
2011-02-15 13:27:54 -05:00
555353c0c5 Rearrange extension-related views as per recent discussion.
The original design of pg_available_extensions did not consider the
possibility of version-specific control files.  Split it into two views:
pg_available_extensions shows information that is generic about an
extension, while pg_available_extension_versions shows all available
versions together with information that could be version-dependent.
Also, add an SRF pg_extension_update_paths() to assist in checking that
a collection of update scripts provide sane update path sequences.
2011-02-14 19:22:36 -05:00
b313bca0af DDL support for collations
- collowner field
- CREATE COLLATION
- ALTER COLLATION
- DROP COLLATION
- COMMENT ON COLLATION
- integration with extensions
- pg_dump support for the above
- dependency management
- psql tab completion
- psql \dO command
2011-02-12 15:55:18 +02:00
d9572c4e3b Core support for "extensions", which are packages of SQL objects.
This patch adds the server infrastructure to support extensions.
There is still one significant loose end, namely how to make it play nice
with pg_upgrade, so I am not yet committing the changes that would make
all the contrib modules depend on this feature.

In passing, fix a disturbingly large amount of breakage in
AlterObjectNamespace() and callers.

Dimitri Fontaine, reviewed by Anssi Kääriäinen,
Itagaki Takahiro, Tom Lane, and numerous others
2011-02-08 16:13:22 -05:00
414c5a2ea6 Per-column collation support
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
2011-02-08 23:04:18 +02:00
ddfe26f644 Avoid maintaining three separate copies of the error codes list.
src/pl/plpgsql/src/plerrcodes.h, src/include/utils/errcodes.h, and a
big chunk of errcodes.sgml are now automatically generated from a single
file, src/backend/utils/errcodes.txt.

Jan Urbański, reviewed by Tom Lane.
2011-02-03 22:32:49 -05:00
56b21b7ae3 Re-classify ERRCODE_DATABASE_DROPPED to 57P04 2011-02-01 08:44:01 +00:00
9e95c9ad55 Create new errcode for recovery conflict caused by db drop on master.
Previously reported as ERRCODE_ADMIN_SHUTDOWN, this case is now
reported as ERRCODE_T_R_DATABASE_DROPPED. No message text change.
Unlikely to happen on most servers, so low impact change to allow
session poolers to correctly handle this situation.

Tatsuo Ishii, edits by me, review by Robert Haas
2011-02-01 00:20:53 +00:00
fb4c5d2798 Code cleanup for assign_XactIsoLevel.
The new coding avoids a spurious debug message when a transaction
that has changed the isolation level has been rolled back.  It also
allows the property to be freely changed to the current value within
a subtransaction.

Kevin Grittner, with one small change by me.
2011-01-21 21:49:19 -05:00
adf328c0e1 Add array_contains_nulls() function in arrayfuncs.c.
This will support fixing contrib/intarray (and probably other places)
so that they don't have to fail on arrays that contain a null bitmap
but no live null entries.
2011-01-08 20:26:14 -05:00
73912e7fbd Fix GIN to support null keys, empty and null items, and full index scans.
Per my recent proposal(s).  Null key datums can now be returned by
extractValue and extractQuery functions, and will be stored in the index.
Also, placeholder entries are made for indexable items that are NULL or
contain no keys according to extractValue.  This means that the index is
now always complete, having at least one entry for every indexed heap TID,
and so we can get rid of the prohibition on full-index scans.  A full-index
scan is implemented much the same way as partial-match scans were already:
we build a bitmap representing all the TIDs found in the index, and then
drive the results off that.

Also, introduce a concept of a "search mode" that can be requested by
extractQuery when the operator requires matching to empty items (this is
just as cheap as matching to a single key) or requires a full index scan
(which is not so cheap, but it sure beats failing or giving wrong answers).
The behavior remains backward compatible for opclasses that don't return
any null keys or request a non-default search mode.

Using these features, we can now make the GIN index opclass for anyarray
behave in a way that matches the actual anyarray operators for &&, <@, @>,
and = ... which it failed to do before in assorted corner cases.

This commit fixes the core GIN code and ginarrayprocs.c, updates the
documentation, and adds some simple regression test cases for the new
behaviors using the array operators.  The tsearch and contrib GIN opclass
support functions still need to be looked over and probably fixed.

Another thing I intend to fix separately is that this is pretty inefficient
for cases where more than one scan condition needs a full-index search:
we'll run duplicate GinScanEntrys, each one of which builds a large bitmap.
There is some existing logic to merge duplicate GinScanEntrys but it needs
refactoring to make it work for entries belonging to different scan keys.

Note that most of gin.h has been split out into a new file gin_private.h,
so that gin.h doesn't export anything that's not supposed to be used by GIN
opclasses or the rest of the backend.  I did quite a bit of other code
beautification work as well, mostly fixing comments and choosing more
appropriate names for things.
2011-01-07 19:16:24 -05:00
0d692a0dc9 Basic foreign table support.
Foreign tables are a core component of SQL/MED.  This commit does
not provide a working SQL/MED infrastructure, because foreign tables
cannot yet be queried.  Support for foreign table scans will need to
be added in a future patch.  However, this patch creates the necessary
system catalog structure, syntax support, and support for ancillary
operations such as COMMENT and SECURITY LABEL.

Shigeru Hanada, heavily revised by Robert Haas
2011-01-01 23:48:11 -05:00
5d950e3b0c Stamp copyrights for year 2011. 2011-01-01 13:18:15 -05:00
53dbc27c62 Support unlogged tables.
The contents of an unlogged table are WAL-logged; thus, they are not
available on standby servers and are truncated whenever the database
system enters recovery.  Indexes on unlogged tables are also unlogged.
Unlogged GiST indexes are not currently supported.
2010-12-29 06:48:53 -05:00
f2ba1e994c Avoid unexpected conversion overflow in planner for distant date values.
The "date" type supports a wider range of dates than int64 timestamps do.
However, there is pre-int64-timestamp code in the planner that assumes that
all date values can be converted to timestamp with impunity.  Fortunately,
what we really need out of the conversion is always a double (float8)
value; so even when the date is out of timestamp's range it's possible to
produce a sane answer.  All we need is a code path that doesn't try to
force the result into int64.  Per trouble report from David Rericha.

Back-patch to all supported versions.  Although this is surely a corner
case, there's not much point in advertising a date range wider than
timestamp's if we will choke on such values in unexpected places.
2010-12-28 22:49:57 -05:00
84fc571395 Rename the C functions bitand(), bitor() to bit_and(), bit_or().
This is to avoid use of the C++ keywords "bitand" and "bitor" in
the header file utils/varbit.h.  Note the functions' SQL-level
names are not changed, only their C-level names.

In passing, make some comments in varbit.c conform to project-standard
layout.
2010-12-27 14:57:41 -05:00
63676ebff4 Corrections to patch adding SQL/MED error codes.
My previous commit, 85cff3ce7f360d139d87aee836d75a6202fee066 on
2010-12-25, failed to update errcodes.sgml or plerrcodes.h.  This patch
corrects that oversight, per a gripe from Tom Lane, and also corrects
a typographical error.
2010-12-26 21:35:25 -05:00
85cff3ce7f Add foreign data wrapper error code values for SQL/MED.
Extracted from a much larger patch by Shigeru Hanada.
2010-12-25 13:57:39 -05:00
03db44eae3 Add pg_read_binary_file() and whole-file-at-once versions of pg_read_file().
One of the usages of the binary version is to read files in a different
encoding from the server encoding.

Dimitri Fontaine and Itagaki Takahiro.
2010-12-16 06:56:28 +09:00
5f7b58fad8 Generalize concept of temporary relations to "relation persistence".
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.
2010-12-13 12:34:26 -05:00
554506871b KNNGIST, otherwise known as order-by-operator support for GIST.
This commit represents a rather heavily editorialized version of
Teodor's builtin_knngist_itself-0.8.2 and builtin_knngist_proc-0.8.1
patches.  I redid the opclass API to add a separate Distance method
instead of turning the Consistent method into an illogical mess,
fixed some bit-rot in the rbtree interfaces, and generally worked over
the code style and comments.

There's still no non-code documentation to speak of, but I'll work on
that separately.  Some contrib-module changes are also yet to come
(right now, point <-> point is the only KNN-ified operator).

Teodor Sigaev and Tom Lane
2010-12-03 20:53:29 -05:00
970a18687f Use GUC lexer for recovery.conf parsing.
This eliminates some crufty, special-purpose code and, as a non-trivial
side benefit, allows recovery.conf parameters to be unquoted.

Dimitri Fontaine, with review and cleanup by Alvaro Herrera, Itagaki
Takahiro, and me.
2010-12-03 08:56:44 -05:00
d583f10b7e Create core infrastructure for KNNGIST.
This is a heavily revised version of builtin_knngist_core-0.9.  The
ordering operators are no longer mixed in with actual quals, which would
have confused not only humans but significant parts of the planner.
Instead, ordering operators are carried separately throughout planning and
execution.

Since the API for ambeginscan and amrescan functions had to be changed
anyway, this commit takes the opportunity to rationalize that a bit.
RelationGetIndexScan no longer forces a premature index_rescan call;
instead, callers of index_beginscan must call index_rescan too.  Aside from
making the AM-side initialization logic a bit less peculiar, this has the
advantage that we do not make a useless extra am_rescan call when there are
runtime key values.  AMs formerly could not assume that the key values
passed to amrescan were actually valid; now they can.

Teodor Sigaev and Tom Lane
2010-12-02 20:51:37 -05:00
c0b5fac701 Simplify and speed up mapping of index opfamilies to pathkeys.
Formerly we looked up the operators associated with each index (caching
them in relcache) and then the planner looked up the btree opfamily
containing such operators in order to build the btree-centric pathkey
representation that describes the index's sort order.  This is quite
pointless for btree indexes: we might as well just use the index's opfamily
information directly.  That saves syscache lookup cycles during planning,
and furthermore allows us to eliminate the relcache's caching of operators
altogether, which may help in reducing backend startup time.

I added code to plancat.c to perform the same type of double lookup
on-the-fly if it's ever faced with a non-btree amcanorder index AM.
If such a thing actually becomes interesting for production, we should
replace that logic with some more-direct method for identifying the
corresponding btree opfamily; but it's not worth spending effort on now.

There is considerably more to do pursuant to my recent proposal to get rid
of sort-operator-based representations of sort orderings, but this patch
grabs some of the low-hanging fruit.  I'll look at the remainder of that
work after the current commitfest.
2010-11-29 12:30:43 -05:00
ba11258ccb When reporting the server as not responding, if the hostname was
supplied, also print the IP address.  This allows IPv4 and IPv6 failures
to be distinguished.  Also useful when a hostname resolves to multiple
IP addresses.

Also, remove use of inet_ntoa() and use our own inet_net_ntop() in all
places, including in libpq, because it is thread-safe.
2010-11-24 17:04:19 -05:00
7504870778 Add new SQL function, format(text).
Currently, three conversion format specifiers are supported: %s for a
string, %L for an SQL literal, and %I for an SQL identifier.  The latter
two are deliberately designed not to overlap with what sprintf() already
supports, in case we want to add more of sprintf()'s functionality here
later.

Patch by Pavel Stehule, heavily revised by me.  Reviewed by Jeff Janes
and, in earlier versions, by Itagaki Takahiro and Tom Lane.
2010-11-20 22:33:27 -05:00
4343c0e546 Expose quote_literal_cstr() from core.
This eliminates the need for inefficient implementions of this
functionality in both contrib/dblink and contrib/tablefunc, so remove
them.  The upcoming patch implementing an in-core format() function
will also require this functionality.

In passing, add some regression tests.
2010-11-20 10:04:48 -05:00
4fc115b2e9 Speed up conversion of signed integers to C strings.
A hand-coded implementation turns out to be much faster than calling
printf().  In passing, add a few more regresion tests.

Andres Freund, with assorted, mostly cosmetic changes.
2010-11-19 22:13:11 -05:00
6cc2deb86e Add pg_describe_object function
This function is useful to obtain textual descriptions of objects as
stored in pg_depend.
2010-11-18 17:06:19 -03:00
186cbbda8f Provide hashing support for arrays.
The core of this patch is hash_array() and associated typcache
infrastructure, which works just about exactly like the existing support
for array comparison.

In addition I did some work to ensure that the planner won't think that an
array type is hashable unless its element type is hashable, and similarly
for sorting.  This includes adding a datatype parameter to op_hashjoinable
and op_mergejoinable, and adding an explicit "hashable" flag to
SortGroupClause.  The lack of a cross-check on the element type was a
pre-existing bug in mergejoin support --- but it didn't matter so much
before, because if you couldn't sort the element type there wasn't any good
alternative to failing anyhow.  Now that we have the alternative of hashing
the array type, there are cases where we can avoid a failure by being picky
at the planner stage, so it's time to be picky.

The issue of exactly how to combine the per-element hash values to produce
an array hash is still open for discussion, but the rest of this is pretty
solid, so I'll commit it as-is.
2010-10-30 21:56:11 -04:00
84c123be1d Allow new values to be added to an existing enum type.
After much expenditure of effort, we've got this to the point where the
performance penalty is pretty minimal in typical cases.

Andrew Dunstan, reviewed by Brendan Jurd, Dean Rasheed, and Tom Lane
2010-10-24 23:05:41 -04:00
529cb267a6 Improve handling of domains over arrays.
This patch eliminates various bizarre behaviors caused by sloppy thinking
about the difference between a domain type and its underlying array type.
In particular, the operation of updating one element of such an array
has to be considered as yielding a value of the underlying array type,
*not* a value of the domain, because there's no assurance that the
domain's CHECK constraints are still satisfied.  If we're intending to
store the result back into a domain column, we have to re-cast to the
domain type so that constraints are re-checked.

For similar reasons, such a domain can't be blindly matched to an ANYARRAY
polymorphic parameter, because the polymorphic function is likely to apply
array-ish operations that could invalidate the domain constraints.  For the
moment, we just forbid such matching.  We might later wish to insert an
automatic downcast to the underlying array type, but such a change should
also change matching of domains to ANYELEMENT for consistency.

To ensure that all such logic is rechecked, this patch removes the original
hack of setting a domain's pg_type.typelem field to match its base type;
the typelem will always be zero instead.  In those places where it's really
okay to look through the domain type with no other logic changes, use the
newly added get_base_element_type function in place of get_element_type.
catversion bumped due to change in pg_type contents.

Per bug #5717 from Richard Huxton and subsequent discussion.
2010-10-21 16:07:17 -04:00
2ec993a7cb Support triggers on views.
This patch adds the SQL-standard concept of an INSTEAD OF trigger, which
is fired instead of performing a physical insert/update/delete.  The
trigger function is passed the entire old and/or new rows of the view,
and must figure out what to do to the underlying tables to implement
the update.  So this feature can be used to implement updatable views
using trigger programming style rather than rule hacking.

In passing, this patch corrects the names of some columns in the
information_schema.triggers view.  It seems the SQL committee renamed
them somewhere between SQL:99 and SQL:2003.

Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
2010-10-10 13:45:07 -04:00