but no database changes have been made since the last CommandCounterIncrement.
This should result in a significant improvement in the number of "commands"
that can typically be performed within a transaction before hitting the 2^32
CommandId size limit. In particular this buys back (and more) the possible
adverse consequences of my previous patch to fix plan caching behavior.
The implementation requires tracking whether the current CommandCounter
value has been "used" to mark any tuples. CommandCounter values stored into
snapshots are presumed not to be used for this purpose. This requires some
small executor changes, since the executor used to conflate the curcid of
the snapshot it was using with the command ID to mark output tuples with.
Separating these concepts allows some small simplifications in executor APIs.
Something for the TODO list: look into having CommandCounterIncrement not do
AcceptInvalidationMessages. It seems fairly bogus to be doing it there,
but exactly where to do it instead isn't clear, and I'm disinclined to mess
with asynchronous behavior during late beta.
plan before the effects of DDL executed in an immediately prior SPI operation
had been absorbed. Per report from Chris Wood.
This patch has an unpleasant side effect of causing the number of
CommandCounterIncrement()s done by a typical plpgsql function to
approximately double. Amelioration of the consequences of that
will be undertaken in a separate patch.
to a UNION, CASE, or related construct are of the same domain type. The
main part of this routine smashes domains to their base types, which seems
necessary because the logic involves TypeCategory() and IsPreferredType(),
neither of which work usefully on domains. However, we can add a first
pass that just detects whether all the inputs are exactly the same type,
and if so accept that without question (so long as it's not UNKNOWN).
Per recent gripe from Dean Rasheed.
In passing, remove some tests for InvalidOid, which have clearly been dead
code for quite some time now, because getBaseType() would fail on that input.
Also, clarify the manual's not-very-precise description of the existing
algorithm's behavior.
Instead put in a test to drop a NULL default at the last moment before
storing the catalog entry. This changes the behavior in a couple of ways:
* Specifying DEFAULT NULL when creating an inheritance child table will
successfully suppress inheritance of any default expression from the
parent's column, where formerly it failed to do so.
* Specifying DEFAULT NULL for a column of a domain type will correctly
override any default belonging to the domain; likewise for a sub-domain.
The latter change happens because by the time the clause is checked,
it won't be a simple null Const but a CoerceToDomain expression.
Personally I think this should be back-patched, but there doesn't seem to
be consensus for that on pgsql-hackers, so refraining.
in corner cases such as re-fetching a just-deleted row. We may be able to
relax this someday, but let's find out how many people really care before
we invest a lot of work in it. Per report from Heikki and subsequent
discussion.
While in the neighborhood, make the combination of INSENSITIVE and FOR UPDATE
throw an error, since they are semantically incompatible. (Up to now we've
accepted but just ignored the INSENSITIVE option of DECLARE CURSOR.)
then-delete on the current cursor row. The basic fix is that nodeTidscan.c
has to apply heap_get_latest_tid() to the current-scan-TID obtained from the
cursor query; this ensures we get the latest row version to work with.
However, since that only works if the query plan is a TID scan, we also have
to hack the planner to make sure only that type of plan will be selected.
(Formerly, the planner might decide to apply a seqscan if the table is very
small. This change is probably a Good Thing anyway, since it's hard to see
how a seqscan could really win.) That means the execQual.c code to support
CurrentOfExpr as a regular expression type is dead code, so replace it with
just an elog(). Also, add regression tests covering these cases. Note
that the added tests expose the fact that re-fetching an updated row
misbehaves if the cursor used FOR UPDATE. That's an independent bug that
should be fixed later. Per report from Dharmendra Goyal.
if there are zero rows to aggregate over, and the API seems both conceptually
and notationally ugly anyway. We should look for something that improves
on the tsquery-and-text-SELECT version (which is also pretty ugly but at
least it works...), but it seems that will take query infrastructure that
doesn't exist today. (Hm, I wonder if there's anything in or near SQL2003
window functions that would help?) Per discussion.
categories, as per discussion. asciiword (formerly lword) is still
ASCII-letters-only, and numword (formerly word) is still the most general
mixed-alpha-and-digits case. But word (formerly nlword) is now
any-group-of-letters-with-at-least-one-non-ASCII, rather than all-non-ASCII as
before. This is no worse than before for parsing mixed Russian/English text,
which seems to have been the design center for the original coding; and it
should simplify matters for parsing most European languages. In particular
it will not be necessary for any language to accept strings containing digits
as being regular "words". The hyphenated-word categories are adjusted
similarly.
a relation as a reason to invalidate a plan when the relation changes. This
handles scenarios such as dropping/recreating a sequence that is referenced by
nextval('seq') in a cached plan. Rather than teach plancache.c all about
digging through plan trees to find regclass Consts, we charge the planner's
setrefs.c with making a list of the relation OIDs on which each plan depends.
That way the list can be built cheaply during a plan tree traversal that has
to happen anyway. Per bug #3662 and subsequent discussion.
* stats_start_collector goes away; we always start the collector process,
unless prevented by a problem with setting up the stats UDP socket.
* stats_reset_on_server_start goes away; it seems useless in view of the
availability of pg_stat_reset().
* stats_block_level and stats_row_level are merged into a single variable
"track_counts", which controls all reports sent to the collector process.
* stats_command_string is renamed to track_activities.
* log_autovacuum is renamed to log_autovacuum_min_duration to better reflect
its meaning.
The log_autovacuum change is not a compatibility issue since it didn't exist
before 8.3 anyway. The other changes need to be release-noted.
Rename synonym.syn.sample and thesaurs.ths.sample to
synonym_sample.syn and thesaurs_sample.ths accordingly to be able to use they
in regression test.
Ispell dictionary uses synthetic simple dictionary files.
transaction, unless rolled back or overridden by a SET clause for the same
variable attached to a surrounding function call. Per discussion, these
seem the best semantics. Note that this is an INCOMPATIBLE CHANGE: in 8.0
through 8.2, SET LOCAL's effects disappeared at subtransaction commit
(leading to behavior that made little sense at the SQL level).
I took advantage of the opportunity to rewrite and simplify the GUC variable
save/restore logic a little bit. The old idea of a "tentative" value is gone;
it was a hangover from before we had a stack. Also, we no longer need a stack
entry for every nesting level, but only for those in which a variable's value
actually changed.
operator-family rewrite. I had mistakenly supposed that these could use the
pg_amproc entries for text[] and inet[] respectively. However, binary
compatibility of the underlying types does not make two array types binary
compatible (since they must differ in the header field that gives the element
type OID), and so the index support code doesn't consider those entries
applicable. Add back the missing pg_amproc entries, and add an opr_sanity
query to try to catch such mistakes in future. Per report from Gregory
Maxwell.
There are still some loose ends: I didn't do anything about the SET FROM
CURRENT idea yet, and it's not real clear whether we are happy with the
interaction of SET LOCAL with function-local settings. The documentation
is a bit spartan, too.
sets for outer joins, in the light of bug #3588 and additional thought and
experimentation. The original methodology was fatally flawed for nests of
more than two outer joins: it got the relationships between adjacent joins
right, but didn't always come to the right conclusions about whether a join
could be interchanged with one two or more levels below it. This was largely
caused by a mistaken idea that we should use the min_lefthand + min_righthand
sets of a sub-join as the minimum left or right input set of an upper join
when we conclude that the sub-join can't commute with the upper one. If
there's a still-lower join that the sub-join *can* commute with, this method
led us to think that that one could commute with the topmost join; which it
can't. Another problem (not directly connected to bug #3588) was that
make_outerjoininfo's processing-order-dependent method for enforcing outer
join identity #3 didn't work right: if we decided that join A could safely
commute with lower join B, we dropped all information about sub-joins under B
that join A could perhaps not safely commute with, because we removed B's
entire min_righthand from A's.
To fix, make an explicit computation of all inner join combinations that occur
below an outer join, and add to that the full syntactic relsets of any lower
outer joins that we determine it can't commute with. This method gives much
more direct enforcement of the outer join rearrangement identities, and it
turns out not to cost a lot of additional bookkeeping.
Thanks to Richard Harris for the bug report and test case.
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.
row within one query: we were firing check triggers before all the updates
were done, leading to bogus failures. Fix by making the triggers queued by
an RI update go at the end of the outer query's trigger event list, thereby
effectively making the processing "breadth-first". This was indeed how it
worked pre-8.0, so the bug does not occur in the 7.x branches.
Per report from Pavel Stehule.
that cached compiled patterns will still be there when the function is next
called. Clean up looping logic, thereby fixing bug identified by Pavel
Stehule. Share setup code between the two functions, add some comments, and
avoid risky mixing of int and size_t variables. Clean up the documentation a
tad, and accept all the flag characters mentioned in table 9-19 rather than
just a subset.
clauses in which one side or the other references both sides of the join
cannot be removed as redundant, because that expression won't have been
constrained below the join. Per report from Sergey Burladyan.
CVS HEAD does not contain this bug due to EquivalenceClass rewrite, but it
seems wise to include the regression test for it anyway.
sugar for PL/PgSQL set-returning functions that want to return the result
of evaluating a query; it should also be more efficient than repeated
RETURN NEXT statements. Based on an earlier patch from Pavel Stehule.
a MIN or MAX aggregate call into an indexscan: the initplan is being made at
the current query nesting level and so we shouldn't increment query_level.
Though usually harmless, this mistake could lead to bogus "plan should not
reference subplan's variable" failures on complex queries. Per bug report
from David Sanchez i Gregori.
referencing table does not change the tuple's FK column(s), we don't bother
to check the PK table since the constraint was presumably already valid.
However, the check is still necessary if the tuple was inserted by our own
transaction, since in that case the INSERT trigger will conclude it need not
make the check (since its version of the tuple has been deleted). We got this
right for simple cases, but not when the insert and update are in different
subtransactions of the current top-level transaction; in such cases the FK
check would never be made at all. (Hence, problem dates back to 8.0 when
subtransactions were added --- it's actually the subtransaction version of a
bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by
Affan Salman.
name. With this patch, it is always possible for the user to qualify a
plpgsql variable name if needed to avoid ambiguity. While there is much more
work to be done in this area, this simple change removes one unnecessary
incompatibility with Oracle. Per discussion.
ORDER BY <constant> as redundant. One is that this means query_planner()
has to canonicalize pathkeys even when the query jointree is empty;
the canonicalization was always a no-op in such cases before, but no more.
Also, we have to guard against thinking that a set-returning function is
"constant" for this purpose. Add a couple of regression tests for these
evidently under-tested cases. Per report from Greg Stark and subsequent
experimentation.
unwarranted liberties with int8 vs float8 values for these types.
Specifically, be sure to apply either hashint8 or hashfloat8 depending
on HAVE_INT64_TIMESTAMP. Per my gripe of even date.
an array of strings rather than an array of integers, and allow any simple
constant or identifier to be used in typmods; for example
create table foo (f1 widget(42,'23skidoo',point));
Of course the typmodin function has still got to pack this info into a
non-negative int32 for storage, but it's still a useful improvement in
flexibility, especially considering that you can do nearly anything if you
are willing to keep the info in a side table. We can get away with this
change since we have not yet released a version providing user-definable
typmods. Per discussion.
historically worked in some but not all cases, but as of 8.2 it failed for all
timezone formats. Fix, and add regression test cases to catch future
regressions in this area. Per gripe from Adam Witney.
Along the way, allow FOR UPDATE in non-WITH-HOLD cursors; there may once
have been a reason to disallow that, but it seems to work now, and it's
really rather necessary if you want to select a row via a cursor and then
update it in a concurrent-safe fashion.
Original patch by Arul Shaji, rather heavily editorialized by Tom Lane.
results due to syncscan patch, when shared_buffers is small enough. Per
buildfarm reports and some local testing with shared_buffers set to the
lowest value considered by initdb.
were accepted by prior Postgres releases. This takes care of the loose end
left by the preceding patch to downgrade implicit casts-to-text. To avoid
breaking desirable behavior for array concatenation, introduce a new
polymorphic pseudo-type "anynonarray" --- the added concatenation operators
are actually text || anynonarray and anynonarray || text.
from the other string-category types; this eliminates a lot of surprising
interpretations that the parser could formerly make when there was no directly
applicable operator.
Create a general mechanism that supports casts to and from the standard string
types (text,varchar,bpchar) for *every* datatype, by invoking the datatype's
I/O functions. These new casts are assignment-only in the to-string direction,
explicit-only in the other, and therefore should create no surprising behavior.
Remove a bunch of thereby-obsoleted datatype-specific casting functions.
The "general mechanism" is a new expression node type CoerceViaIO that can
actually convert between *any* two datatypes if their external text
representations are compatible. This is more general than needed for the
immediate feature, but might be useful in plpgsql or other places in future.
This commit does nothing about the issue that applying the concatenation
operator || to non-text types will now fail, often with strange error messages
due to misinterpreting the operator as array concatenation. Since it often
(not always) worked before, we should either make it succeed or at least give
a more user-friendly error; but details are still under debate.
Peter Eisentraut and Tom Lane
type. Also, add explicit casts between boolean and text/varchar. Both
of these changes are for conformance with SQL:2003.
Update the regression tests, bump the catversion.
"microsecond" and "millisecond" units were not considered valid input
by themselves, which caused inputs like "1 millisecond" to be rejected
erroneously.
Update the docs, add regression tests, and backport to 8.2 and 8.1
inheritance child of an UPDATE/DELETE target relation can be excluded by
constraints. I had rearranged some code in set_append_rel_pathlist() to
avoid "useless" work when a child is excluded, but overdid it and left
the child with no cheapest_path entry, causing possible failure later
if the appendrel was involved in a join. Also, it seems that the dummy
plan generated by inheritance_planner() when all branches are excluded
has to be a bit less dummy now than was required in 8.2.
Per report from Jan Wieck. Add his test case to the regression tests.
in cases where a sub-SELECT inserts a WHERE clause between two outer joins,
that clause may prevent us from re-ordering the two outer joins. The code
was considering only the joins' own ON-conditions in determining reordering
safety, which is not good enough. Add a "delay_upper_joins" flag to
OuterJoinInfo to flag that we have detected such a clause and higher-level
outer joins shouldn't be permitted to commute with this one. (This might
seem overly coarse, but given the current rules for OJ reordering, it's
sufficient AFAICT.)
The failure case is actually pretty narrow: it needs a WHERE clause within
the RHS of a left join that checks the RHS of a lower left join, but is not
strict for that RHS (else we'd have simplified the lower join to a plain
join). Even then no failure will be manifest unless the planner chooses to
rearrange the join order.
Per bug report from Adam Terrey.
