Commit Graph

2162 Commits

Author SHA1 Message Date
Tom Lane
21c8ee7946 Sync backend/parser/scan.l with bin/psql/psqlscan.l.
Make some minor formatting adjustments to make it easier to diff these
files and see that they indeed implement the same flex rules (at least
to the extent that we want them to be the same).

(Someday it'd be nice to make ecpg's pgc.l more easily diff'able too,
but today is not that day.)

Also run relevant parts of these files and psqlscanslash.l through
pgindent.

No actual behavioral changes here, just obsessive neatnik-ism.
2016-03-19 14:36:22 -04:00
Tom Lane
72b1e3a21f Build backend/parser/scan.l and interfaces/ecpg/preproc/pgc.l standalone.
Now that we know about the %top{} trick, we can revert to building flex
lexers as separate .o files.  This is worth doing for a couple of reasons
besides sheer cleanliness.  We can narrow the scope of the -Wno-error flag
that's forced on scan.c.  Also, since these grammar and lexer files are
so large, splitting them into separate build targets should have some
advantages in build speed, particularly in parallel or ccache'd builds.

We have quite a few other .l files that could be changed likewise, but the
above arguments don't apply to them, so the benefit of fixing them seems
pretty minimal.  Leave the rest for some other day.
2016-03-19 12:07:24 -04:00
Teodor Sigaev
3187d6de0e Introduce parse_ident()
SQL-layer function to split qualified identifier into array parts.

Author: Pavel Stehule with minor editorization by me and Jim Nasby
2016-03-18 18:16:14 +03:00
Robert Haas
3aff33aa68 Fix typos.
Oskari Saarenmaa
2016-03-15 18:06:11 -04:00
Tom Lane
364a9f47ab Refactor pull_var_clause's API to make it less tedious to extend.
In commit 1d97c19a0f and later c1d9579dd8, we extended
pull_var_clause's API by adding enum-type arguments.  That's sort of a pain
to maintain, though, because it means every time we add a new behavior we
must touch every last one of the call sites, even if there's a reasonable
default behavior that most of them could use.  Let's switch over to using a
bitmask of flags, instead; that seems more maintainable and might save a
nanosecond or two as well.  This commit changes no behavior in itself,
though I'm going to follow it up with one that does add a new behavior.

In passing, remove flatten_tlist(), which has not been used since 9.1
and would otherwise need the same API changes.

Removing these enums means that optimizer/tlist.h no longer needs to
depend on optimizer/var.h.  Changing that caused a number of C files to
need addition of #include "optimizer/var.h" (probably we can thank old
runs of pgrminclude for that); but on balance it seems like a good change
anyway.
2016-03-10 15:53:07 -05:00
Tom Lane
d31f20e2b5 Fix copy-and-pasteo in comment.
Wensheng Zhang
2016-03-09 10:29:14 -05:00
Tom Lane
72eee410d4 Move pg_constraint.h function declarations to new file pg_constraint_fn.h.
A pending patch requires exporting a function returning Bitmapset from
catalog/pg_constraint.c.  As things stand, that would mean including
nodes/bitmapset.h in pg_constraint.h, which might be hazardous for the
client-side includability of that header.  It's not entirely clear whether
any client-side code needs to include pg_constraint.h, but it seems prudent
to assume that there is some such code somewhere.  Therefore, split off the
function definitions into a new file pg_constraint_fn.h, similarly to what
we've done for some other catalog header files.
2016-02-11 15:51:28 -05:00
Tom Lane
a396144ac0 Remove new coupling between NAMEDATALEN and MAX_LEVENSHTEIN_STRLEN.
Commit e529cd4ffa introduced an Assert requiring NAMEDATALEN to be
less than MAX_LEVENSHTEIN_STRLEN, which has been 255 for a long time.
Since up to that instant we had always allowed NAMEDATALEN to be
substantially more than that, this was ill-advised.

It's debatable whether we need MAX_LEVENSHTEIN_STRLEN at all (versus
putting a CHECK_FOR_INTERRUPTS into the loop), or whether it has to be
so tight; but this patch takes the narrower approach of just not applying
the MAX_LEVENSHTEIN_STRLEN limit to calls from the parser.

Trusting the parser for this seems reasonable, first because the strings
are limited to NAMEDATALEN which is unlikely to be hugely more than 256,
and second because the maximum distance is tightly constrained by
MAX_FUZZY_DISTANCE (though we'd forgotten to make use of that limit in one
place).  That means the cost is not really O(mn) but more like O(max(m,n)).

Relaxing the limit for user-supplied calls is left for future research;
given the lack of complaints to date, it doesn't seem very high priority.

In passing, fix confusion between lengths-in-bytes and lengths-in-chars
in comments and error messages.

Per gripe from Kevin Day; solution suggested by Robert Haas.  Back-patch
to 9.5 where the unwanted restriction was introduced.
2016-01-22 11:53:06 -05:00
Tom Lane
b99551832e Add defenses against putting expanded objects into Const nodes.
Putting a reference to an expanded-format value into a Const node would be
a bad idea for a couple of reasons.  It'd be possible for the supposedly
immutable Const to change value, if something modified the referenced
variable ... in fact, if the Const's reference were R/W, any function that
has the Const as argument might itself change it at runtime.  Also, because
datumIsEqual() is pretty simplistic, the Const might fail to compare equal
to other Consts that it should compare equal to, notably including copies
of itself.  This could lead to unexpected planner behavior, such as "could
not find pathkey item to sort" errors or inferior plans.

I have not been able to find any way to get an expanded value into a Const
within the existing core code; but Paul Ramsey was able to trigger the
problem by writing a datatype input function that returns an expanded
value.

The best fix seems to be to establish a rule that varlena values being
placed into Const nodes should be passed through pg_detoast_datum().
That will do nothing (and cost little) in normal cases, but it will flatten
expanded values and thereby avoid the above problems.  Also, it will
convert short-header or compressed values into canonical format, which will
avoid possible unexpected lack-of-equality issues for those cases too.
And it provides a last-ditch defense against putting a toasted value into
a Const, which we already knew was dangerous, cf commit 2b0c86b665.
(In the light of this discussion, I'm no longer sure that that commit
provided 100% protection against such cases, but this fix should do it.)

The test added in commit 65c3d05e18 to catch datatype input functions
with unstable results would fail for functions that returned expanded
values; but it seems a bit uncharitable to deem a result unstable just
because it's expressed in expanded form, so revise the coding so that we
check for bitwise equality only after applying pg_detoast_datum().  That's
a sufficient condition anyway given the new rule about detoasting when
forming a Const.

Back-patch to 9.5 where the expanded-object facility was added.  It's
possible that this should go back further; but in the absence of clear
evidence that there's any live bug in older branches, I'll refrain for now.
2016-01-21 12:56:08 -05:00
Robert Haas
a7de3dc5c3 Support multi-stage aggregation.
Aggregate nodes now have two new modes: a "partial" mode where they
output the unfinalized transition state, and a "finalize" mode where
they accept unfinalized transition states rather than individual
values as input.

These new modes are not used anywhere yet, but they will be necessary
for parallel aggregation.  The infrastructure also figures to be
useful for cases where we want to aggregate local data and remote
data via the FDW interface, and want to bring back partial aggregates
from the remote side that can then be combined with locally generated
partial aggregates to produce the final value.  It may also be useful
even when neither FDWs nor parallelism are in play, as explained in
the comments in nodeAgg.c.

David Rowley and Simon Riggs, reviewed by KaiGai Kohei, Heikki
Linnakangas, Haribabu Kommi, and me.
2016-01-20 13:46:50 -05:00
Tom Lane
65c5fcd353 Restructure index access method API to hide most of it at the C level.
This patch reduces pg_am to just two columns, a name and a handler
function.  All the data formerly obtained from pg_am is now provided
in a C struct returned by the handler function.  This is similar to
the designs we've adopted for FDWs and tablesample methods.  There
are multiple advantages.  For one, the index AM's support functions
are now simple C functions, making them faster to call and much less
error-prone, since the C compiler can now check function signatures.
For another, this will make it far more practical to define index access
methods in installable extensions.

A disadvantage is that SQL-level code can no longer see attributes
of index AMs; in particular, some of the crosschecks in the opr_sanity
regression test are no longer possible from SQL.  We've addressed that
by adding a facility for the index AM to perform such checks instead.
(Much more could be done in that line, but for now we're content if the
amvalidate functions more or less replace what opr_sanity used to do.)
We might also want to expose some sort of reporting functionality, but
this patch doesn't do that.

Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily
editorialized on by me.
2016-01-17 19:36:59 -05:00
Bruce Momjian
ee94300446 Update copyright for 2016
Backpatch certain files through 9.1
2016-01-02 13:33:40 -05:00
Tom Lane
6efbded6e4 Allow omitting one or both boundaries in an array slice specifier.
Omitted boundaries represent the upper or lower limit of the corresponding
array subscript.  This allows simpler specification of many common
use-cases.

(Revised version of commit 9246af6799)

YUriy Zhuravlev
2015-12-22 21:05:29 -05:00
Teodor Sigaev
bbbd807097 Revert 9246af6799 because
I miss too much. Patch is returned to commitfest process.
2015-12-18 21:35:22 +03:00
Teodor Sigaev
9246af6799 Allow to omit boundaries in array subscript
Allow to omiy lower or upper or both boundaries in array subscript
for selecting slice of array.

Author: YUriy Zhuravlev
2015-12-18 15:18:58 +03:00
Robert Haas
f27a6b15e6 Mark CHECK constraints declared NOT VALID valid if created with table.
FOREIGN KEY constraints have behaved this way for a long time, but for
some reason the behavior of CHECK constraints has been inconsistent up
until now.

Amit Langote and Amul Sul, with assorted tweaks by me.
2015-12-16 07:43:56 -05:00
Teodor Sigaev
92e38182d7 COPY (INSERT/UPDATE/DELETE .. RETURNING ..)
Attached is a patch for being able to do COPY (query) without a CTE.

Author: Marko Tiikkaja
Review: Michael Paquier
2015-11-27 19:11:22 +03:00
Peter Eisentraut
5db837d3f2 Message improvements 2015-11-16 21:39:23 -05:00
Peter Eisentraut
a8d585c091 Message style improvements
Message style, plurals, quoting, spelling, consistency with similar
messages
2015-10-28 20:38:36 -04:00
Robert Haas
31ba62ce32 Fix typos in comments.
CharSyam
2015-10-22 14:52:23 -04:00
Tom Lane
d371bebd3d Remove redundant CREATEUSER/NOCREATEUSER options in CREATE ROLE et al.
Once upon a time we did not have a separate CREATEROLE privilege, and
CREATEUSER effectively meant SUPERUSER.  When we invented CREATEROLE
(in 8.1) we also added SUPERUSER so as to have a less confusing keyword
for this role property.  However, we left CREATEUSER in place as a
deprecated synonym for SUPERUSER, because of backwards-compatibility
concerns.  It's still there and is still confusing people, as for example
in bug #13694 from Justin Catterson.  9.6 will be ten years or so later,
which surely ought to be long enough to end the deprecation and just
remove these old keywords.  Hence, do so.
2015-10-22 09:34:03 -07:00
Bruce Momjian
b943f502b7 Have CREATE TABLE LIKE add OID column if any LIKEd table has one
Also, process constraints for LIKEd tables at the end so an OID column
can be referenced in a constraint.

Report by Tom Lane
2015-10-05 21:19:16 -04:00
Stephen Frost
088c83363a ALTER TABLE .. FORCE ROW LEVEL SECURITY
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.
2015-10-04 21:05:08 -04:00
Andres Freund
b67aaf21e8 Add CASCADE support for CREATE EXTENSION.
Without CASCADE, if an extension has an unfullfilled dependency on
another extension, CREATE EXTENSION ERRORs out with "required extension
... is not installed". That is annoying, especially when that dependency
is an implementation detail of the extension, rather than something the
extension's user can make sense of.

In addition to CASCADE this also includes a small set of regression
tests around CREATE EXTENSION.

Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund
Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes
Discussion: 557E0520.3040800@2ndquadrant.com
2015-10-03 18:23:40 +02:00
Andres Freund
ad22783792 Fix several bugs related to ON CONFLICT's EXCLUDED pseudo relation.
Four related issues:

1) attnos/varnos/resnos for EXCLUDED were out of sync when a column
   after one dropped in the underlying relation was referenced.
2) References to whole-row variables (i.e. EXCLUDED.*) lead to errors.
3) It was possible to reference system columns in the EXCLUDED pseudo
   relations, even though they would not have valid contents.
4) References to EXCLUDED were rewritten by the RLS machinery, as
   EXCLUDED was treated as if it were the underlying relation.

To fix the first two issues, generate the excluded targetlist with
dropped columns in mind and add an entry for whole row
variables. Instead of unconditionally adding a wholerow entry we could
pull up the expression if needed, but doing it unconditionally seems
simpler. The wholerow entry is only really needed for ruleutils/EXPLAIN
support anyway.

The remaining two issues are addressed by changing the EXCLUDED RTE to
have relkind = composite. That fits with EXCLUDED not actually being a
real relation, and allows to treat it differently in the relevant
places. scanRTEForColumn now skips looking up system columns when the
RTE has a composite relkind; fireRIRrules() already had a corresponding
check, thereby preventing RLS expansion on EXCLUDED.

Also add tests for these issues, and improve a few comments around
excluded handling in setrefs.c.

Reported-By: Peter Geoghegan, Geoff Winkless
Author: Andres Freund, Amit Langote, Peter Geoghegan
Discussion: CAEzk6fdzJ3xYQZGbcuYM2rBd2BuDkUksmK=mY9UYYDugg_GgZg@mail.gmail.com,
   CAM3SWZS+CauzbiCEcg-GdE6K6ycHE_Bz6Ksszy8AoixcMHOmsA@mail.gmail.com
Backpatch: 9.5, where ON CONFLICT was introduced
2015-10-03 15:12:10 +02:00
Robert Haas
7aea8e4f2d Determine whether it's safe to attempt a parallel plan for a query.
Commit 924bcf4f16 introduced a framework
for parallel computation in PostgreSQL that makes most but not all
built-in functions safe to execute in parallel mode.  In order to have
parallel query, we'll need to be able to determine whether that query
contains functions (either built-in or user-defined) that cannot be
safely executed in parallel mode.  This requires those functions to be
labeled, so this patch introduces an infrastructure for that.  Some
functions currently labeled as safe may need to be revised depending on
how pending issues related to heavyweight locking under paralllelism
are resolved.

Parallel plans can't be used except for the case where the query will
run to completion.  If portal execution were suspended, the parallel
mode restrictions would need to remain in effect during that time, but
that might make other queries fail.  Therefore, this patch introduces
a framework that enables consideration of parallel plans only when it
is known that the plan will be run to completion.  This probably needs
some refinement; for example, at bind time, we do not know whether a
query run via the extended protocol will be execution to completion or
run with a limited fetch count.  Having the client indicate its
intentions at bind time would constitute a wire protocol break.  Some
contexts in which parallel mode would be safe are not adjusted by this
patch; the default is not to try parallel plans except from call sites
that have been updated to say that such plans are OK.

This commit doesn't introduce any parallel paths or plans; it just
provides a way to determine whether they could potentially be used.
I'm committing it on the theory that the remaining parallel sequential
scan patches will also get committed to this release, hopefully in the
not-too-distant future.

Robert Haas and Amit Kapila.  Reviewed (in earlier versions) by Noah
Misch.
2015-09-16 15:38:47 -04:00
Stephen Frost
3c99788797 Rename 'cmd' to 'cmd_name' in CreatePolicyStmt
To avoid confusion, rename CreatePolicyStmt's 'cmd' to 'cmd_name',
parse_policy_command's 'cmd' to 'polcmd', and AlterPolicy's 'cmd_datum'
to 'polcmd_datum', per discussion with Noah and as a follow-up to his
correction of copynodes/equalnodes handling of the CreatePolicyStmt
'cmd' field.

Back-patch to 9.5 where the CreatePolicyStmt was introduced, as we
are still only in alpha.
2015-08-21 08:22:22 -04:00
Tom Lane
1e3e1ae266 Remove gram.y's precedence declaration for OVERLAPS.
The allowed syntax for OVERLAPS, viz "row OVERLAPS row", is sufficiently
constrained that we don't actually need a precedence declaration for
OVERLAPS; indeed removing this declaration does not change the generated
gram.c file at all.  Let's remove it to avoid confusion about whether
OVERLAPS has precedence or not.  If we ever generalize what we allow for
OVERLAPS, we might need to put back a precedence declaration for it,
but we might want some other level than what it has today --- and leaving
the declaration there would just risk confusion about whether that would
be an incompatible change.

Likewise, remove OVERLAPS from the documentation's precedence table.

Per discussion with Noah Misch.  Back-patch to 9.5 where we hacked up some
nearby precedence decisions.
2015-08-09 19:01:04 -04:00
Heikki Linnakangas
804163bc25 Share transition state between different aggregates when possible.
If there are two different aggregates in the query with same inputs, and
the aggregates have the same initial condition and transition function,
only calculate the state value once, and only call the final functions
separately. For example, AVG(x) and SUM(x) aggregates have the same
transition function, which accumulates the sum and number of input tuples.
For a query like "SELECT AVG(x), SUM(x) FROM x", we can therefore
accumulate the state function only once, which gives a nice speedup.

David Rowley, reviewed and edited by me.
2015-08-04 17:53:10 +03:00
Andrew Dunstan
2cd40adb85 Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN
Fabrízio de Royes Mello, reviewed by Payal Singh, Alvaro Herrera and
Michael Paquier.
2015-07-29 21:30:00 -04:00
Joe Conway
632cd9f892 Create new ParseExprKind for use by policy expressions.
Policy USING and WITH CHECK expressions were using EXPR_KIND_WHERE for
parse analysis, which results in inappropriate ERROR messages when
the expression contains unsupported constructs such as aggregates.
Create a new ParseExprKind called EXPR_KIND_POLICY and tailor the
related messages to fit.

Reported by Noah Misch. Reviewed by Dean Rasheed, Alvaro Herrera,
and Robert Haas. Back-patch to 9.5 where RLS was introduced.
2015-07-29 15:40:24 -07:00
Andres Freund
faab14ecb8 Fix flattening of nested grouping sets.
Previously nested grouping set specifications accidentally weren't
flattened, but instead contained the nested specification as a element
in the outer list.

Fix this by, as actually documented in comments, concatenating the
nested set specification into the outer one. Also add tests to prevent
this from breaking again.

Author: Andrew Gierth, with tests from Jeevan Chalke
Reported-By: Jeevan Chalke
Discussion: CAM2+6=V5YvuxB+EyN4iH=GbD-XTA435TCNvnDFSD--YvXs+pww@mail.gmail.com
Backpatch: 9.5, where grouping sets were introduced
2015-07-26 16:50:29 +02:00
Tom Lane
dd7a8f66ed Redesign tablesample method API, and do extensive code review.
The original implementation of TABLESAMPLE modeled the tablesample method
API on index access methods, which wasn't a good choice because, without
specialized DDL commands, there's no way to build an extension that can
implement a TSM.  (Raw inserts into system catalogs are not an acceptable
thing to do, because we can't undo them during DROP EXTENSION, nor will
pg_upgrade behave sanely.)  Instead adopt an API more like procedural
language handlers or foreign data wrappers, wherein the only SQL-level
support object needed is a single handler function identified by having
a special return type.  This lets us get rid of the supporting catalog
altogether, so that no custom DDL support is needed for the feature.

Adjust the API so that it can support non-constant tablesample arguments
(the original coding assumed we could evaluate the argument expressions at
ExecInitSampleScan time, which is undesirable even if it weren't outright
unsafe), and discourage sampling methods from looking at invisible tuples.
Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable
within and across queries, as required by the SQL standard, and deal more
honestly with methods that can't support that requirement.

Make a full code-review pass over the tablesample additions, and fix
assorted bugs, omissions, infelicities, and cosmetic issues (such as
failure to put the added code stanzas in a consistent ordering).
Improve EXPLAIN's output of tablesample plans, too.

Back-patch to 9.5 so that we don't have to support the original API
in production.
2015-07-25 14:39:00 -04:00
Andres Freund
c1ca3a19df Fix bug around assignment expressions containing indirections.
Handling of assigned-to expressions with indirection (e.g. set f1[1] =
3) was broken for ON CONFLICT DO UPDATE.  The problem was that
ParseState was consulted to determine if an INSERT-appropriate or
UPDATE-appropriate behavior should be used when transforming expressions
with indirections. When the wrong path was taken the old row was
substituted with NULL, leading to wrong results..

To fix remove p_is_update and only use p_is_insert to decide how to
transform the assignment expression, and uset p_is_insert while parsing
the on conflict statement. This isn't particularly pretty, but it's not
any worse than before.

Author: Peter Geoghegan, slightly edited by me
Discussion: CAM3SWZS8RPvA=KFxADZWw3wAHnnbxMxDzkEC6fNaFc7zSm411w@mail.gmail.com
Backpatch: 9.5, where the feature was introduced
2015-07-24 11:52:07 +02:00
Heikki Linnakangas
321eed5f0f Add ALTER OPERATOR command, for changing selectivity estimator functions.
Other options cannot be changed, as it's not totally clear if cached plans
would need to be invalidated if one of the other options change. Selectivity
estimator functions only change plan costs, not correctness of plans, so
those should be safe.

Original patch by Uriy Zhuravlev, heavily edited by me.
2015-07-14 18:17:55 +03:00
Tom Lane
0a52d378b0 Avoid passing NULL to memcmp() in lookups of zero-argument functions.
A few places assumed they could pass NULL for the argtypes array when
looking up functions known to have zero arguments.  At first glance
it seems that this should be safe enough, since memcmp() is surely not
allowed to fetch any bytes if its count argument is zero.  However,
close reading of the C standard says that such calls have undefined
behavior, so we'd probably best avoid it.

Since the number of places doing this is quite small, and some other
places looking up zero-argument functions were already passing dummy
arrays, let's standardize on the latter solution rather than hacking
the function lookup code to avoid calling memcmp() in these cases.
I also added Asserts to catch any future violations of the new rule.

Given the utter lack of any evidence that this actually causes any
problems in the field, I don't feel a need to back-patch this change.

Per report from Piotr Stefaniak, though this is not his patch.
2015-06-27 17:47:39 -04:00
Bruce Momjian
807b9e0dff pgindent run for 9.5 2015-05-23 21:35:49 -04:00
Tom Lane
a6a66bd647 Another typo fix.
In the spirit of the season.
2015-05-20 14:50:22 -04:00
Heikki Linnakangas
4fc72cc7bb Collection of typo fixes.
Use "a" and "an" correctly, mostly in comments. Two error messages were
also fixed (they were just elogs, so no translation work required). Two
function comments in pg_proc.h were also fixed. Etsuro Fujita reported one
of these, but I found a lot more with grep.

Also fix a few other typos spotted while grepping for the a/an typos.
For example, "consists out of ..." -> "consists of ...". Plus a "though"/
"through" mixup reported by Euler Taveira.

Many of these typos were in old code, which would be nice to backpatch to
make future backpatching easier. But much of the code was new, and I didn't
feel like crafting separate patches for each branch. So no backpatching.
2015-05-20 16:56:22 +03:00
Andres Freund
9bc77c4519 Various fixes around ON CONFLICT for rule deparsing.
Neither the deparsing of the new alias for INSERT's target table, nor of
the inference clause was supported. Also fixup a typo in an error
message.

Add regression tests to test those code paths.

Author: Peter Geoghegan
2015-05-19 23:18:57 +02:00
Andres Freund
0740cbd759 Refactor ON CONFLICT index inference parse tree representation.
Defer lookup of opfamily and input type of a of a user specified opclass
until the optimizer selects among available unique indexes; and store
the opclass in the parse analyzed tree instead.  The primary reason for
doing this is that for rule deparsing it's easier to use the opclass
than the previous representation.

While at it also rename a variable in the inference code to better fit
it's purpose.

This is separate from the actual fixes for deparsing to make review
easier.
2015-05-19 21:21:27 +02:00
Peter Eisentraut
0779f2ba2d Fix parse tree of DROP TRANSFORM and COMMENT ON TRANSFORM
The plain C string language name needs to be wrapped in makeString() so
that the parse tree is copyable.  This is detectable by
-DCOPY_PARSE_PLAN_TREES.  Add a test case for the COMMENT case.

Also make the quoting in the error messages more consistent.

discovered by Tom Lane
2015-05-18 22:55:14 -04:00
Andres Freund
f3d3118532 Support GROUPING SETS, CUBE and ROLLUP.
This SQL standard functionality allows to aggregate data by different
GROUP BY clauses at once. Each grouping set returns rows with columns
grouped by in other sets set to NULL.

This could previously be achieved by doing each grouping as a separate
query, conjoined by UNION ALLs. Besides being considerably more concise,
grouping sets will in many cases be faster, requiring only one scan over
the underlying data.

The current implementation of grouping sets only supports using sorting
for input. Individual sets that share a sort order are computed in one
pass. If there are sets that don't share a sort order, additional sort &
aggregation steps are performed. These additional passes are sourced by
the previous sort step; thus avoiding repeated scans of the source data.

The code is structured in a way that adding support for purely using
hash aggregation or a mix of hashing and sorting is possible. Sorting
was chosen to be supported first, as it is the most generic method of
implementation.

Instead of, as in an earlier versions of the patch, representing the
chain of sort and aggregation steps as full blown planner and executor
nodes, all but the first sort are performed inside the aggregation node
itself. This avoids the need to do some unusual gymnastics to handle
having to return aggregated and non-aggregated tuples from underlying
nodes, as well as having to shut down underlying nodes early to limit
memory usage.  The optimizer still builds Sort/Agg node to describe each
phase, but they're not part of the plan tree, but instead additional
data for the aggregation node. They're a convenient and preexisting way
to describe aggregation and sorting.  The first (and possibly only) sort
step is still performed as a separate execution step. That retains
similarity with existing group by plans, makes rescans fairly simple,
avoids very deep plans (leading to slow explains) and easily allows to
avoid the sorting step if the underlying data is sorted by other means.

A somewhat ugly side of this patch is having to deal with a grammar
ambiguity between the new CUBE keyword and the cube extension/functions
named cube (and rollup). To avoid breaking existing deployments of the
cube extension it has not been renamed, neither has cube been made a
reserved keyword. Instead precedence hacking is used to make GROUP BY
cube(..) refer to the CUBE grouping sets feature, and not the function
cube(). To actually group by a function cube(), unlikely as that might
be, the function name has to be quoted.

Needs a catversion bump because stored rules may change.

Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund
Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas
    Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule
Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:46:31 +02:00
Simon Riggs
f6d208d6e5 TABLESAMPLE, SQL Standard and extensible
Add a TABLESAMPLE clause to SELECT statements that allows
user to specify random BERNOULLI sampling or block level
SYSTEM sampling. Implementation allows for extensible
sampling functions to be written, using a standard API.
Basic version follows SQLStandard exactly. Usable
concrete use cases for the sampling API follow in later
commits.

Petr Jelinek

Reviewed by Michael Paquier and Simon Riggs
2015-05-15 14:37:10 -04:00
Fujii Masao
ecd222e770 Support VERBOSE option in REINDEX command.
When this option is specified, a progress report is printed as each index
is reindexed.

Per discussion, we agreed on the following syntax for the extensibility of
the options.

    REINDEX (flexible options) { INDEX | ... } name

Sawada Masahiko.
Reviewed by Robert Haas, Fabrízio Mello, Alvaro Herrera, Kyotaro Horiguchi,
Jim Nasby and me.

Discussion: CAD21AoA0pK3YcOZAFzMae+2fcc3oGp5zoRggDyMNg5zoaWDhdQ@mail.gmail.com
2015-05-15 20:09:57 +09:00
Alvaro Herrera
b488c580ae Allow on-the-fly capture of DDL event details
This feature lets user code inspect and take action on DDL events.
Whenever a ddl_command_end event trigger is installed, DDL actions
executed are saved to a list which can be inspected during execution of
a function attached to ddl_command_end.

The set-returning function pg_event_trigger_ddl_commands can be used to
list actions so captured; it returns data about the type of command
executed, as well as the affected object.  This is sufficient for many
uses of this feature.  For the cases where it is not, we also provide a
"command" column of a new pseudo-type pg_ddl_command, which is a
pointer to a C structure that can be accessed by C code.  The struct
contains all the info necessary to completely inspect and even
reconstruct the executed command.

There is no actual deparse code here; that's expected to come later.
What we have is enough infrastructure that the deparsing can be done in
an external extension.  The intention is that we will add some deparsing
code in a later release, as an in-core extension.

A new test module is included.  It's probably insufficient as is, but it
should be sufficient as a starting point for a more complete and
future-proof approach.

Authors: Álvaro Herrera, with some help from Andres Freund, Ian Barwick,
Abhijit Menon-Sen.

Reviews by Andres Freund, Robert Haas, Amit Kapila, Michael Paquier,
Craig Ringer, David Steele.
Additional input from Chris Browne, Dimitri Fontaine, Stephen Frost,
Petr Jelínek, Tom Lane, Jim Nasby, Steven Singer, Pavel Stěhule.

Based on original work by Dimitri Fontaine, though I didn't use his
code.

Discussion:
  https://www.postgresql.org/message-id/m2txrsdzxa.fsf@2ndQuadrant.fr
  https://www.postgresql.org/message-id/20131108153322.GU5809@eldon.alvh.no-ip.org
  https://www.postgresql.org/message-id/20150215044814.GL3391@alvh.no-ip.org
2015-05-11 19:14:31 -03:00
Andres Freund
168d5805e4 Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.
The newly added ON CONFLICT clause allows to specify an alternative to
raising a unique or exclusion constraint violation error when inserting.
ON CONFLICT refers to constraints that can either be specified using a
inference clause (by specifying the columns of a unique constraint) or
by naming a unique or exclusion constraint.  DO NOTHING avoids the
constraint violation, without touching the pre-existing row.  DO UPDATE
SET ... [WHERE ...] updates the pre-existing tuple, and has access to
both the tuple proposed for insertion and the existing tuple; the
optional WHERE clause can be used to prevent an update from being
executed.  The UPDATE SET and WHERE clauses have access to the tuple
proposed for insertion using the "magic" EXCLUDED alias, and to the
pre-existing tuple using the table name or its alias.

This feature is often referred to as upsert.

This is implemented using a new infrastructure called "speculative
insertion". It is an optimistic variant of regular insertion that first
does a pre-check for existing tuples and then attempts an insert.  If a
violating tuple was inserted concurrently, the speculatively inserted
tuple is deleted and a new attempt is made.  If the pre-check finds a
matching tuple the alternative DO NOTHING or DO UPDATE action is taken.
If the insertion succeeds without detecting a conflict, the tuple is
deemed inserted.

To handle the possible ambiguity between the excluded alias and a table
named excluded, and for convenience with long relation names, INSERT
INTO now can alias its target table.

Bumps catversion as stored rules change.

Author: Peter Geoghegan, with significant contributions from Heikki
    Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes.
Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs,
    Dean Rasheed, Stephen Frost and many others.
2015-05-08 05:43:10 +02:00
Andres Freund
2c8f4836db Represent columns requiring insert and update privileges indentently.
Previously, relation range table entries used a single Bitmapset field
representing which columns required either UPDATE or INSERT privileges,
despite the fact that INSERT and UPDATE privileges are separately
cataloged, and may be independently held.  As statements so far required
either insert or update privileges but never both, that was
sufficient. The required permission could be inferred from the top level
statement run.

The upcoming INSERT ... ON CONFLICT UPDATE feature needs to
independently check for both privileges in one statement though, so that
is not sufficient anymore.

Bumps catversion as stored rules change.

Author: Peter Geoghegan
Reviewed-By: Andres Freund
2015-05-08 00:20:46 +02:00
Noah Misch
b339a5cf90 Rename coerce_type() local variable.
coerce_type() has local variables named targetTypeId, baseTypeId, and
targetType.  targetType has been the Type structure for baseTypeId, so
rename it to baseType.
2015-05-02 16:46:23 -04:00
Robert Haas
e044a44949 Deparse named arguments to use the new => operator instead of :=
Tom Lane pointed out that this wasn't done, and asked whether that was
intentional.  Subsequent discussion was in favor of making the change,
so here we go.
2015-05-01 09:37:10 -04:00