have cursors that might outlive their creating transactions. A
patch is attached that fixes this (suggestions on better wording
are welcome).
Neil Conway
via extended query protocol, because it sends Sync right after Execute
without realizing that the command to be executed is COPY. There seems
to be no reasonable way for it to realize that, either, so the best fix
seems to be to make the backend ignore Sync during copy-in mode. Bit of
a wart on the protocol, but little alternative. Also, libpq must send
another Sync after terminating the COPY, if the command was issued via
Execute.
libpq users to perform Bind/Execute of previously prepared statements.
Per yesterday's discussion, this offers enough performance improvement
to justify bending the 'no new features during beta' rule.
he supplied a few months ago, but didn't get around to docing until now. And
he also added some doc for calling stored functions in general from jdbc that was missing.
Modified Files:
sgml/jdbc.sgml
heuristic determination of day vs month in date/time input. Add the
ability to specify that input is interpreted as yy-mm-dd order (which
formerly worked, but only for yy greater than 31). DateStyle's input
component now has the preferred spellings DMY, MDY, or YMD; the older
keywords European and US are now aliases for the first two of these.
Per recent discussions on pgsql-general.
>>ISTM that "source" is worth knowing.
>
> Hm, possibly. Any other opinions?
This version has the seven fields I proposed, including "source". Here's
an example that shows why I think it's valuable:
regression=# \x
Expanded display is on.
regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name | enable_seqscan
setting | on
context | user
vartype | bool
source | default
min_val |
max_val |
regression=# update pg_settings set setting = 'off' where name =
'enable_seqscan';
-[ RECORD 1 ]---
set_config | off
regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name | enable_seqscan
setting | off
context | user
vartype | bool
source | session
min_val |
max_val |
regression=# alter user postgres set enable_seqscan to 'off';
ALTER USER
(log out and then back in again)
regression=# \x
Expanded display is on.
regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name | enable_seqscan
setting | off
context | user
vartype | bool
source | user
min_val |
max_val |
In the first case, enable_seqscan is set to its default value. After
setting it to off, it is obvious that the value has been changed for the
session only. In the third case, you can see that the value has been set
specifically for the user.
Joe Conway
psql4win32.patch - changes in the psql source code
psql-ref.patch - changes in the documentation psql-ref.sgml
(for new builtin variable WIN32_CONSOLE)
To apply them use "patch -p 1" in the root directory of the
postgres source directory.
These patches fix the following problems of psql on Win32
(all changes only have effect #ifdef WIN32):
a) Problem: Static library libpq.a did not work
Solution: Added WSAStartup() in fe-connect.c
b) Problem: Secret Password was echoed by psql
Solution: Password echoing disabled in sprompt.c
c) Problem: 8bit characters were displayed/interpreted wrong in psql
This is due to the fact that the Win32 "console" uses a
different encoding than the rest of the Windows system
Solution: Introduced a new psql variable WIN32_CONSOLE
When set with "\set WIN32_console", the function OemToChar()
is applied after reading input and CharToOem() before
displaying Output
Christoph Dalitz
modes (and replace the requiressl boolean). The four options were first
spelled out by Magnus Hagander <mha@sollentuna.net> on 2000-08-23 in email
to pgsql-hackers, archived here:
http://archives.postgresql.org/pgsql-hackers/2000-08/msg00639.php
My original less-flexible patch and the ensuing thread are archived at:
http://dbforums.com/t623845.html
Attached is a new patch, including documentation.
To sum up, there's a new client parameter "sslmode" and environment
variable "PGSSLMODE", with these options:
sslmode description
------- -----------
disable Unencrypted non-SSL only
allow Negotiate, prefer non-SSL
prefer Negotiate, prefer SSL (default)
require Require SSL
The only change to the server is a new pg_hba.conf line type,
"hostnossl", for specifying connections that are not allowed to use SSL
(for example, to prevent servers on a local network from accidentally
using SSL and wasting cycles). Thus the 3 pg_hba.conf line types are:
pg_hba.conf line types
----------------------
host applies to either SSL or regular connections
hostssl applies only to SSL connections
hostnossl applies only to regular connections
These client and server options, the postgresql.conf ssl = false option,
and finally the possibility of compiling with no SSL support at all,
make quite a range of combinations to test. I threw together a test
script to try many of them out. It's in a separate tarball with its
config files, a patch to psql so it'll announce SSL connections even in
absence of a tty, and the test output. The test is especially informative
when run on the same tty the postmaster was started on, so the FATAL:
errors during negotiation are interleaved with the psql client output.
I saw Tom write that new submissions for 7.4 have to be in before midnight
local time, and since I'm on the east coast in the US, this just makes it
in before the bell. :)
Jon Jensen
> Well, no. What it says is that certain values must be escaped (but
> doesn't say which ones). Then it says there are alternate escape
> sequences for some values, which it lists.
>
> It doesn't say "The following table contains the characters which must
> be escaped:", which would be much clearer (and actually useful).
Attached documentation patch updates the wording for bytea input
escaping, per complaint by Stephen Norris above.
Joe Conway
for the sign of timezone offsets, ie, positive is east from UTC. These
were previously out of step with other operations that accept or show
timezones, such as I/O of timestamptz values.
and 100 respectively, if the platform will allow it. initdb selects
values that are not too large to allow the postmaster to start, and
places these values in the installed postgresql.conf file. This allows
us to continue to start up out-of-the-box on platforms with small SHMMAX,
while having somewhat-realistic default settings on platforms with
reasonable SHMMAX. Per recent pghackers discussion.
without needing a running backend. Reorder postgresql.conf.sample
to match new layout of runtime.sgml. This commit re-adds work lost
in Wednesday's crash.
'scalar op ALL (array)', where the operator is applied between the
lefthand scalar and each element of the array. The operator must
yield boolean; the result of the construct is the OR or AND of the
per-element results, respectively.
Original coding by Joe Conway, after an idea of Peter's. Rewritten
by Tom to keep the implementation strictly separate from subqueries.
client-side AUTOCOMMIT mode now: '\set AUTOCOMMIT off' supports
SQL-spec commit behavior. Get rid of LO_TRANSACTION hack --- the
LO operations just work now, using libpq's ability to track the
transaction status. Add a VERBOSE variable to control verboseness
of error message display, and add a %T prompt-string code to show
current transaction-block status. Superuser state display in the
prompt string correctly follows SET SESSION AUTHORIZATION commands.
Control-C works to get out of COPY IN state.
comparison functions), replacing the highly bogus bitwise array_eq. Create
a btree index opclass for ANYARRAY --- it is now possible to create indexes
on array columns.
Arrange to cache the results of catalog lookups across multiple array
operations, instead of repeating the lookups on every call.
Add string_to_array and array_to_string functions.
Remove singleton_array, array_accum, array_assign, and array_subscript
functions, since these were for proof-of-concept and not intended to become
supported functions.
Minor adjustments to behavior in some corner cases with empty or
zero-dimensional arrays.
Joe Conway (with some editorializing by Tom Lane).
identifier, while some areas do not.
The attached converts be below to "name":
conversion_name
index_name
The below have an existing, initdb supplied, entity named "name". As
such, it could be confusing for the reader to see that identifier used
in the example.
domainname
typename
Rod Taylor
with advocacy and 'portal' websites.
Link to createdb / dropdb from the tutorial page about create / dropdb.
A pair of notes were asking about more info...
Rod Taylor
Regression tests for IPv6 operations added.
Documentation updated to document IPv6 bits.
Stop treating IPv4 as an "unsigned int" and IPv6 as an array of
characters. Instead, always use the array of characters so we
can have one function fits all. This makes bitncmp(), addressOK(),
and several other functions "just work" on both address families.
add family() function which returns integer 4 or 6 for IPv4 or
IPv6. (See examples below) Note that to add this new function
you will need to dump/initdb/reload or find the correct magic
to add the function to the postgresql function catalogs.
IPv4 addresses always sort before IPv6.
On disk we use AF_INET for IPv4, and AF_INET+1 for IPv6 addresses.
This prevents the need for a dump and reload, but lets IPv6 parsing
work on machines without AF_INET6.
To select all IPv4 addresses from a table:
select * from foo where family(addr) = 4 ...
Order by and other bits should all work.
Michael Graff
specific hash functions used by hash indexes, rather than the old
not-datatype-aware ComputeHashFunc routine. This makes it safe to do
hash joining on several datatypes that previously couldn't use hashing.
The sets of datatypes that are hash indexable and hash joinable are now
exactly the same, whereas before each had some that weren't in the other.
out of mind, because it'd been commented out years ago). Try to bring the
remains up to a reasonable level of currency, and give it all approximately
the same high level of abstraction.
character in identifiers. The first change eliminates the current need
to put spaces around parameter references, as in "x<=$2". The second
change improves compatibility with Oracle and some other RDBMSes. This
was discussed and agreed to back in January, but did not get done.
not all SQL identifiers taken from command line arguments. We decided
years ago that that was a bad idea: identifiers taken from the command
line should be treated as literally correct. Remove the inconsistent
code that has crept in recently. Also fix pg_dump so that the combination
of --schema and --table does what you'd expect, namely dump exactly one
table from exactly one schema. Per gripe from Deepak Bhole of Red Hat.
extensions to support our historical behavior. An aggregate belongs
to the closest query level of any of the variables in its argument,
or the current query level if there are no variables (e.g., COUNT(*)).
The implementation involves adding an agglevelsup field to Aggref,
and treating outer aggregates like outer variables at planning time.
of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects). This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up. Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
blanks, in hopes of reducing the surprise factor for newbies. Remove
redundant operators for VARCHAR (it depends wholly on TEXT operations now).
Clean up resolution of ambiguous operators/functions to avoid surprising
choices for domains: domains are treated as equivalent to their base types
and binary-coercibility is no longer considered a preference item when
choosing among multiple operators/functions. IsBinaryCoercible now correctly
reflects the notion that you need *only* relabel the type to get from type
A to type B: that is, a domain is binary-coercible to its base type, but
not vice versa. Various marginal cleanup, including merging the essentially
duplicate resolution code in parse_func.c and parse_oper.c. Improve opr_sanity
regression test to understand about binary compatibility (using pg_cast),
and fix a couple of small errors in the catalogs revealed thereby.
Restructure "special operator" handling to fetch operators via index opclasses
rather than hardwiring assumptions about names (cleans up the pattern_ops
stuff a little).
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON. Still TODO: provide some client-side autocommit
logic in libpq.
of Describe on a prepared statement. This was in the original 3.0
protocol proposal, but I took it out for reasons that seemed good at
the time. Put it back per yesterday's pghackers discussion.
implementation limits, do not issue an ERROR; instead issue a NOTICE and use
the max supported value. Per pgsql-general discussion of 28-Apr, this is
needed to allow easy porting from pre-7.3 releases where the limits were
higher.
Unrelated change in same area: accept GLOBAL TEMP/TEMPORARY as a synonym
for TEMPORARY, as per pgsql-hackers discussion of 15-Apr. We previously
rejected it, but that was based on a misreading of the spec --- SQL92's
GLOBAL temp tables are really closer to what we have than their LOCAL ones.
Both plannable queries and utility commands are now always executed
within Portals, which have been revamped so that they can handle the
load (they used to be good only for single SELECT queries). Restructure
code to push command-completion-tag selection logic out of postgres.c,
so that it won't have to be duplicated between simple and extended queries.
initdb forced due to addition of a field to Query nodes.
for tableID/columnID in RowDescription. (The latter isn't really
implemented yet though --- the backend always sends zeroes, and libpq
just throws away the data.)
initial values and runtime changes in selected parameters. This gets
rid of the need for an initial 'select pg_client_encoding()' query in
libpq, bringing us back to one message transmitted in each direction
for a standard connection startup. To allow server version to be sent
using the same GUC mechanism that handles other parameters, invent the
concept of a never-settable GUC parameter: you can 'show server_version'
but it's not settable by any GUC input source. Create 'lc_collate' and
'lc_ctype' never-settable parameters so that people can find out these
settings without need for pg_controldata. (These side ideas were all
discussed some time ago in pgsql-hackers, but not yet implemented.)
rewritten and the protocol is changed, but most elog calls are still
elog calls. Also, we need to contemplate mechanisms for controlling
all this functionality --- eg, how much stuff should appear in the
postmaster log? And what API should libpq expose for it?
have length words. COPY OUT reimplemented per new protocol: it doesn't
need \. anymore, thank goodness. COPY BINARY to/from frontend works,
at least as far as the backend is concerned --- libpq's PQgetline API
is not up to snuff, and will have to be replaced with something that is
null-safe. libpq uses message length words for performance improvement
(no cycles wasted rescanning long messages), but not yet for error
recovery.
with variable-width fields. No more truncation of long user names.
Also, libpq can now send its environment-variable-driven SET commands
as part of the startup packet, saving round trips to server.
some message types. In particular add text/binary flag to StartCopyIn
and StartCopyOut, so that client library can know what is expected or
forthcoming.
chapters on extending types, operators, and aggregates into the extending
functions chapter. Move the information on how to call table functions
into the queries chapter. Remove some outdated information that is
already present in a better form in other parts of the documentation.
find out about it is to read the documentation that tells you how
dangerous it is. Add default_transaction_read_only to documentation;
seems to have been overlooked in patch that added read-only transactions.
Clean up check_guc comparison script, which has been suffering bit rot.
page when it's read in, per pghackers discussion around 17-Feb. Add a
GUC variable zero_damaged_pages that causes the response to be a WARNING
followed by zeroing the page, rather than the normal ERROR; this is per
Hiroshi's suggestion that there needs to be a way to get at the data
in the rest of the table.
(materialization into a tuple store) discussed on pgsql-hackers earlier.
I've updated the documentation and the regression tests.
Notes on the implementation:
- I needed to change the tuple store API slightly -- it assumes that it
won't be used to hold data across transaction boundaries, so the temp
files that it uses for on-disk storage are automatically reclaimed at
end-of-transaction. I added a flag to tuplestore_begin_heap() to control
this behavior. Is changing the tuple store API in this fashion OK?
- in order to store executor results in a tuple store, I added a new
CommandDest. This works well for the most part, with one exception: the
current DestFunction API doesn't provide enough information to allow the
Executor to store results into an arbitrary tuple store (where the
particular tuple store to use is chosen by the call site of
ExecutorRun). To workaround this, I've temporarily hacked up a solution
that works, but is not ideal: since the receiveTuple DestFunction is
passed the portal name, we can use that to lookup the Portal data
structure for the cursor and then use that to get at the tuple store the
Portal is using. This unnecessarily ties the Portal code with the
tupleReceiver code, but it works...
The proper fix for this is probably to change the DestFunction API --
Tom suggested passing the full QueryDesc to the receiveTuple function.
In that case, callers of ExecutorRun could "subclass" QueryDesc to add
any additional fields that their particular CommandDest needed to get
access to. This approach would work, but I'd like to think about it for
a little bit longer before deciding which route to go. In the mean time,
the code works fine, so I don't think a fix is urgent.
- (semi-related) I added a NO SCROLL keyword to DECLARE CURSOR, and
adjusted the behavior of SCROLL in accordance with the discussion on
-hackers.
- (unrelated) Cleaned up some SGML markup in sql.sgml, copy.sgml
Neil Conway
functions
* Document pg_conversion_is_visible() which was created in one of my
previous patches and didn't get documented for some reason
Christopher Kings-Lynne
them as arrays of the internal datatype. This requires treating the
stavalues columns as 'anyarray' rather than 'text[]', which is not 100%
kosher but seems to work fine for the purposes we need for pg_statistic.
Perhaps in the future 'anyarray' will be allowed more generally.
some of the algorithms for higher functions. I see about a factor of ten
speedup on the 'numeric' regression test, but it's unlikely that that test
is representative of real-world applications.
initdb forced due to change of on-disk representation for NUMERIC.
effectively used to mean a default value that could also be spelled
out explicitly. (ACLs behave that way, and useconfig/datconfig
do too IIRC.)
It's a bit of a hack, but it saves table space and backend code ---
without this convention the default would have to be inserted "manually"
since we have no mechanism to supply defaults when C code is forming a
new catalog tuple.
I'm inclined to leave the code alone. But Alvaro is right that it'd be
good to point out the 'infinity' option in the CREATE USER and ALTER
USER man pages. (Doc patch please?)
Alvaro Herrera
join is defined as:
from_item [ NATURAL ] join_type from_item
[ ON join_condition | USING ( join_column_list ) ]
However, if the join_type is an INNER or OUTER join, an ON, USING, or
NATURAL clause *must* be specified (it's not optional, as that segment
of the docs suggest).
I'm not exactly sure what the best way to fix this is, so I've attached
a patch adding a FIXME comment to the relevant section of the SGML. If
anyone has any ideas on the proper way to outline join syntax, please
speak up.
Neil Conway <neilc@samurai.com> || PGP Key ID: DB3C29FC
Add ALTER SEQUENCE to modify min/max/increment/cache/cycle values
Also updated create sequence docs to mention NO MINVALUE, & NO MAXVALUE.
New Files:
doc/src/sgml/ref/alter_sequence.sgml
src/test/regress/expected/sequence.out
src/test/regress/sql/sequence.sql
ALTER SEQUENCE is NOT transactional. It behaves similarly to setval().
It matches the proposed SQL200N spec, as well as Oracle in most ways --
Oracle lacks RESTART WITH for some strange reason.
--
Rod Taylor <rbt@rbt.ca>
Envrironment and Files section, explained exactly what -w
does)
This is a patch which allows pg_ctl to make an intelligent
guess as to the proper port when running 'psql -l' to
determine if the database has started up (the -w flag).
The environment variable PGPORT is used. If that is not found,
it checks if a specific port has been set inside the postgresql.conf
file. If it is has not, it uses the port that Postgres was
compiled with.
Greg Sabino Mullane greg@turnstep.com
> weird behavior across fork boundaries; (b) the additional memory space
> that has to be duplicated into child processes will cost something per
> child launch, even if the child never uses it. But these are only
> arguments that it might not *always* be a prudent thing to do, not that
> we shouldn't give the DBA the tool to do it if he wants. So fire away.
Here is a patch for the above, including a documentation update. It
creates a new GUC variable "preload_libraries", that accepts a list in
the form:
preload_libraries = '$libdir/mylib1:initfunc,$libdir/mylib2'
If ":initfunc" is omitted or not found, no initialization function is
executed, but the library is still preloaded. If "$libdir/mylib" isn't
found, the postmaster refuses to start.
In my testing with PL/R, it reduces the first call to a PL/R function
(after connecting) from almost 2 seconds, down to about 8 ms.
Joe Conway
utility statement (DeclareCursorStmt) with a SELECT query dangling from
it, rather than a SELECT query with a few unusual fields in it. Add
code to determine whether a planned query can safely be run backwards.
If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run
backwards by adding a Materialize plan node if it can't. Without SCROLL,
you get an error if you try to fetch backwards from a cursor that can't
handle it. (There is still some discussion about what the exact
behavior should be, but this is necessary infrastructure in any case.)
Along the way, make EXPLAIN DECLARE CURSOR work.
Adjustable threshold is gone in favor of keeping track of total requested
page storage and doling out proportional fractions to each relation
(with a minimum amount per relation, and some quantization of the results
to avoid thrashing with small changes in page counts). Provide special-
case code for indexes so as not to waste space storing useless page
free space counts. Restructure internal data storage to be a flat array
instead of list-of-chunks; this may cost a little more work in data
copying when reorganizing, but allows binary search to be used during
lookup_fsm_page_entry().
now knows what to do upon hitting a dead page (in theory anyway, it's
untested...). Add a post-VACUUM-cleanup entry point for index AMs, to
provide a place for dead-page scavenging to happen.
Also, fix oversight that broke btpo_prev links in temporary indexes.
initdb forced due to additions in pg_am.
- more work from the SGML police
- some grammar improvements: rewriting a paragraph or two, replacing
contractions where (IMHO) appropriate
- fix missing utility commands in lock mode docs
- improve CLUSTER, REINDEX, SET SESSION AUTHORIZATION ref pages
Neil Conway
functions which limited the maximum date for a timestamp to AD 1465001.
The new limit is AD 5874897.
The files affected are:
doc/src/sgml/datatype.sgml:
Documentation change due to patch. Included is a notice about
the reduced range when using an eight-byte integer for timestamps.
src/backend/utils/adt/datetime.c:
Replacement functions for j2date() and date2j() functions.
src/include/utils/datetime.h:
Corrected a bug with the limit on the earliest possible date,
Nov 23,-4713 has a Julian day count of -1. The earliest possible
date should be Nov 24, -4713 with a day count of 0.
src/test/regress/expected/horology-no-DST-before-1970.out:
src/test/regress/expected/horology-solaris-1947.out:
src/test/regress/expected/horology.out:
Copies of expected output for regression testing.
Note: Only horology.out has been physically tested. I do not have access
to a Solaris box and I don't know how to provoke the "pre-1970" test.
src/test/regress/sql/horology.sql:
Added some test cases to check extended range.
John Cochran
performance of min() and max() is slow when applied to the entire table,
and suggesting the simple workaround most experienced Pg users
eventually learn about (SELECT xyz ... ORDER BY xyz LIMIT 1).
Neil Conway
> > comma).
>
> OK. But the documentation implies there is a comma, so it should probably
> get chenged then.
Yes, it should. (attached)
[ Backpatched to 7.3.X too.]
Rod Taylor
takes two parameters, an OID x and an integer y, and returns "true" with
probability 1/y (the OID argument is ignored). This can be useful -- for
example, it can be used to select a random sampling of the rows in a
table (which is what the "random" regression test uses it for).
This patch removes that function, because it was old and messy. The old
function had the following problems:
- it was undocumented
- it was poorly named
- it was designed to workaround an optimizer bug that no longer exists
(the OID argument is to ensure that the optimizer won't optimize away
calls to the function; AFAIK marking the function as 'volatile' suffices
nowadays)
- it used a different random-number generation technique than the other
PSRNG-related functions in the backend do (it called random() like they
do, but it had its own logic for setting a set and deciding when to
reseed the RNG).
Ok, this patch removes oidrand(), oidsrand(), and userfntest(), and
improves the SGML docs a little bit (un-commenting the setseed()
documentation).
Neil Conway
On Wed, 2003-01-08 at 21:59, Christopher Kings-Lynne wrote:
> I agree. I want to remove OIDs from heaps of our tables when we go to 7.3.
> I'd rather not have to do it in the dump due to down time.
Rod Taylor <rbt@rbt.ca>
> I don't care what you use for short options if all useful ones are taken.
> But the long option should be --schema.
Ok, fair enough: a revised patch is attached that uses the '-n' short
option and the '--schema' long option.
Neil Conway
expression accepted by the regex operators, per discussion yesterday.
Along the way, reduce deadlock_timeout from PGC_POSTMASTER to PGC_SIGHUP
category. It is probably best to insist that all backends share the same
setting, but that doesn't mean it has to be frozen at startup.
(extracted from Tcl 8.4.1 release, as Henry still hasn't got round to
making it a separate library). This solves a performance problem for
multibyte, as well as upgrading our regexp support to match recent Tcl
and nearly match recent Perl.
restriction was debatable to begin with, but it has now become obvious
that it breaks forward-porting of user-defined types; contrib/lo being
the most salient example.
for type 'time without time zone', as we already did for type
'timestamp without time zone'. This patch was proposed by Tom Lockhart
on 7-Nov-02, but he never got around to applying it. Adjust regression
tests and documentation to match.
value of MAX_TIME_PRECISION in floating-point-timestamp-storage case
from 13 to 10, which is as much as time_out is actually willing to print.
(The alternative of increasing the number of digits we are willing to
print looks risky; we might find ourselves printing roundoff garbage.)
passed to join selectivity estimators. Make use of this in eqjoinsel
to derive non-bogus selectivity for IN clauses. Further tweaking of
cost estimation for IN.
initdb forced because of pg_proc.h changes.
necessarily following the JOIN syntax to develop the query plan. The old
behavior is still available by setting GUC variable JOIN_COLLAPSE_LIMIT
to 1. Also create a GUC variable FROM_COLLAPSE_LIMIT to control the
similar decision about when to collapse sub-SELECT lists into their parent
lists. (This behavior existed already, but the limit was always
GEQO_THRESHOLD/2; now it's separately adjustable.)
that's selecting into a RECORD variable returns zero rows, make it
assign an all-nulls row to the RECORD; this is consistent with what
happens when the SELECT INTO target is not a RECORD. In support of
this, tweak the SPI code so that a valid tuple descriptor is returned
even when a SPI select returns no rows.
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
including:
- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on
- fix an omission in the EXECUTE documentation
- add some more text to the EXPLAIN documentation
- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)
- minor markup fixes
Neil Conway
Bruce Momjian
Tom Lane
Barry Lind
Peter Eisentraut