Commit Graph

76 Commits

Author SHA1 Message Date
Bruce Momjian 9e1552607a pgindent run. Make it all clean. 2001-03-22 04:01:46 +00:00
Tom Lane 13cc7eb3e2 Clean up two rather nasty bugs in operator selection code.
1. If there is exactly one pg_operator entry of the right name and oprkind,
oper() and related routines would return that entry whether its input type
had anything to do with the request or not.  This is just premature
optimization: we shouldn't return the single candidate until after we verify
that it really is a valid candidate, ie, is at least coercion-compatible
with the given types.

2. oper() and related routines only promise a coercion-compatible result.
Unfortunately, there were quite a few callers that assumed the returned
operator is binary-compatible with the given datatype; they would proceed
to call it without making any datatype coercions.  These callers include
sorting, grouping, aggregation, and VACUUM ANALYZE.  In general I think
it is appropriate for these callers to require an exact or binary-compatible
match, so I've added a new routine compatible_oper() that only succeeds if
it can find an operator that doesn't require any run-time conversions.
Callers now call oper() or compatible_oper() depending on whether they are
prepared to deal with type conversion or not.

The upshot of these bugs is revealed by the following silliness in PL/Tcl's
selftest: it creates an operator @< on int4, and then tries to use it to
sort a char(N) column.  The system would let it do that :-( (and evidently
has done so since 6.3 :-( :-().  The result in this case was just a silly
sort order, but the reverse combination would've provoked coredump from
trying to dereference integers.  With this fix you get more reasonable
behavior:
pltcl_test=# select * from T_pkey1 order by key1, key2 using @<;
ERROR:  Unable to identify an operator '@<' for types 'bpchar' and 'bpchar'
        You will have to retype this query using an explicit cast
2001-02-16 03:16:58 +00:00
Tom Lane db3ac67d8f Update comments about memory management. 2001-02-15 21:47:08 +00:00
Bruce Momjian 623bf843d2 Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group. 2001-01-24 19:43:33 +00:00
Tom Lane a933ee38bb Change SearchSysCache coding conventions so that a reference count is
maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.
2000-11-16 22:30:52 +00:00
Tom Lane 782c16c6a1 SQL-language functions are now callable in ordinary fmgr contexts ...
for example, an SQL function can be used in a functional index.  (I make
no promises about speed, but it'll work ;-).)  Clean up and simplify
handling of functions returning sets.
2000-08-24 03:29:15 +00:00
Tom Lane bec98a31c5 Revise aggregate functions per earlier discussions in pghackers.
There's now only one transition value and transition function.
NULL handling in aggregates is a lot cleaner.  Also, use Numeric
accumulators instead of integer accumulators for sum/avg on integer
datatypes --- this avoids overflow at the cost of being a little slower.
Implement VARIANCE() and STDDEV() aggregates in the standard backend.

Also, enable new LIKE selectivity estimators by default.  Unrelated
change, but as long as I had to force initdb anyway...
2000-07-17 03:05:41 +00:00
Tom Lane badce86a2c First stage of reclaiming memory in executor by resetting short-term
memory contexts.  Currently, only leaks in expressions executed as
quals or projections are handled.  Clean up some old dead cruft in
executor while at it --- unused fields in state nodes, that sort of thing.
2000-07-12 02:37:39 +00:00
Tom Lane 1aebc3618a First phase of memory management rewrite (see backend/utils/mmgr/README
for details).  It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably.  A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing.  Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.
2000-06-28 03:33:33 +00:00
Bruce Momjian df43800fc8 Clean up #include's. 2000-06-15 03:33:12 +00:00
Tom Lane 0f1e39643d Third round of fmgr updates: eliminate calls using fmgr() and
fmgr_faddr() in favor of new-style calls.  Lots of cleanup of
sloppy casts to use XXXGetDatum and DatumGetXXX ...
2000-05-30 04:25:00 +00:00
Bruce Momjian a12a23f0d0 Remove unused include files. Do not touch /port or includes used by defines. 2000-05-30 00:49:57 +00:00
Tom Lane 0a7fb4e918 First round of changes for new fmgr interface. fmgr itself and the
key call sites are changed, but most called functions are still oldstyle.
An exception is that the PL managers are updated (so, for example, NULL
handling now behaves as expected in plperl and plpgsql functions).
NOTE initdb is forced due to added column in pg_proc.
2000-05-28 17:56:29 +00:00
Bruce Momjian 52f77df613 Ye-old pgindent run. Same 4-space tabs. 2000-04-12 17:17:23 +00:00
Bruce Momjian 5c25d60244 Add:
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc

to all files copyright Regents of Berkeley.  Man, that's a lot of files.
2000-01-26 05:58:53 +00:00
Tom Lane 6d1efd76fb Fix handling of NULL constraint conditions: per SQL92 spec, a NULL result
from a constraint condition does not violate the constraint (cf. discussion
on pghackers 12/9/99).  Implemented by adding a parameter to ExecQual,
specifying whether to return TRUE or FALSE when the qual result is
really NULL in three-valued boolean logic.  Currently, ExecRelCheck is
the only caller that asks for TRUE, but if we find any other places that
have the wrong response to NULL, it'll be easy to fix them.
2000-01-19 23:55:03 +00:00
Tom Lane a8ae19ec3d aggregate(DISTINCT ...) works, per SQL spec.
Note this forces initdb because of change of Aggref node in stored rules.
1999-12-13 01:27:21 +00:00
Tom Lane c60ecd8f8c Ooops ... 6.5 coding wasn't quite right anymore. Should learn
never to commit without running regress tests...
1999-10-30 02:35:14 +00:00
Tom Lane b021e9a130 Put back code in nodeAgg to generate a dummy all-nulls input tuple
before calling execProject, when the outerPlan has returned zero tuples.
I took this out under the mistaken impression that the input tuple
couldn't be referenced by execProject if we weren't in GROUP BY mode.
But it can, if we're in an UPDATE or DELETE...
1999-10-30 01:18:16 +00:00
Tom Lane 5ce158c534 Remove a no-longer-needed kluge for degenerate aggregate cases,
and update some comments.
1999-10-08 03:49:55 +00:00
Tom Lane a55888ec9c Fix nodeAgg coredump in case where lower-level plan has
an empty targetlist *and* fails to return any tuples, as will happen
for example with 'SELECT COUNT(1) FROM table WHERE ...' if the where-
clause selects no tuples.  It's so nice to make a fix by diking out code,
instead of adding more...
1999-09-28 02:03:19 +00:00
Tom Lane be09bc9ff2 Modify nodeAgg.c so that no rows are returned for a GROUP BY
with no input rows, per pghackers discussions around 7/22/99.  Clean up
a bunch of ugly coding while at it; remove redundant re-lookup of
aggregate info at start of each new GROUP.  Arrange to pfree intermediate
values when they are pass-by-ref types, so that aggregates on pass-by-ref
types no longer eat memory.  This takes care of a couple of TODO items...
1999-09-26 21:21:15 +00:00
Tom Lane 78114cd4d4 Further planner/optimizer cleanups. Move all set_tlist_references
and fix_opids processing to a single recursive pass over the plan tree
executed at the very tail end of planning, rather than haphazardly here
and there at different places.  Now that tlist Vars do not get modified
until the very end, it's possible to get rid of the klugy var_equal and
match_varid partial-matching routines, and just use plain equal()
throughout the optimizer.  This is a step towards allowing merge and
hash joins to be done on expressions instead of only Vars ...
1999-08-22 20:15:04 +00:00
Tom Lane db436adf76 Major revision of sort-node handling: push knowledge of query
sort order down into planner, instead of handling it only at the very top
level of the planner.  This fixes many things.  An explicit sort is now
avoided if there is a cheaper alternative (typically an indexscan) not
only for ORDER BY, but also for the internal sort of GROUP BY.  It works
even when there is no other reason (such as a WHERE condition) to consider
the indexscan.  It works for indexes on functions.  It works for indexes
on functions, backwards.  It's just so cool...

CAUTION: I have changed the representation of SortClause nodes, therefore
THIS UPDATE BREAKS STORED RULES.  You will need to initdb.
1999-08-21 03:49:17 +00:00
Bruce Momjian 3406901a29 Move some system includes into c.h, and remove duplicates. 1999-07-17 20:18:55 +00:00
Bruce Momjian a71802e12e Final cleanup. 1999-07-16 05:00:38 +00:00
Bruce Momjian 2e6b1e63a3 Remove unused #includes in *.c files. 1999-07-15 22:40:16 +00:00
Bruce Momjian 4b2c2850bf Clean up #include in /include directory. Add scripts for checking includes. 1999-07-15 15:21:54 +00:00
Bruce Momjian 0c3281ce7c Reversed out Massimo patch. 1999-06-12 14:07:33 +00:00
Bruce Momjian 603e153bb8 I don't like last minute patches before the final freeze, but I believe that
this one could be useful for people experiencing out-of-memory crashes while
executing queries which retrieve or use a very large number of tuples.

The problem happens when storage is allocated for functions results used in
a large query, for example:

  select upper(name) from big_table;
  select big_table.array[1] from big_table;
  select count(upper(name)) from big_table;

This patch is a dirty hack that fixes the out-of-memory problem for the most
common cases, like the above ones. It is not the final solution for the
problem but it can work for some people, so I'm posting it.

The patch should be safe because all changes are under #ifdef. Furthermore
the feature can be enabled or disabled at runtime by the `free_tuple_memory'
options in the pg_options file. The option is disabled by default and must
be explicitly enabled at runtime to have any effect.

To enable the patch add the follwing line to Makefile.custom:

CUSTOM_COPT += -DFREE_TUPLE_MEMORY

To enable the option at runtime add the following line to pg_option:

free_tuple_memory=1

Massimo
1999-06-12 14:05:41 +00:00
Bruce Momjian fcff1cdf4e Another pgindent run. Sorry folks. 1999-05-25 22:43:53 +00:00
Bruce Momjian 07842084fe pgindent run over code. 1999-05-25 16:15:34 +00:00
Tom Lane fd31563777 Aggregate functions didn't work on subscripted array references.
Things are better now.
1999-04-29 01:13:13 +00:00
Tom Lane 419b91c058 Correct some comments, fix a small memory wastage when datatype
is pass-by-value.
1999-03-21 19:59:13 +00:00
Bruce Momjian 0aa2aed5f8 Reverse out pfree agg part of patch from Erik Riedel. 1999-03-20 13:18:20 +00:00
Bruce Momjian 7d0ab659ac Fix for aggregate memory leaks from Erik Riedel. 1999-03-20 01:13:22 +00:00
Bruce Momjian 6724a50787 Change my-function-name-- to my_function_name, and optimizer renames. 1999-02-13 23:22:53 +00:00
Bruce Momjian d611ccb874 fix for aggregates 1999-01-27 16:15:01 +00:00
Bruce Momjian 36693c0525 More agg cleanup. 1999-01-26 23:32:04 +00:00
Bruce Momjian 1401f63dd1 Agg/Aggreg cleanup and datetime.sql patch. 1999-01-25 18:02:28 +00:00
Bruce Momjian 17467bb7fb Rename Aggreg to Aggref. 1999-01-24 00:28:37 +00:00
Bruce Momjian bd8ffc6f3f Hi!
INTERSECT and EXCEPT is available for postgresql-v6.4!

The patch against v6.4 is included at the end of the current text
(in uuencoded form!)

I also included the text of my Master's Thesis. (a postscript
version). I hope that you find something of it useful and would be
happy if parts of it find their way into the PostgreSQL documentation
project (If so, tell me, then I send the sources of the document!)

The contents of the document are:
  -) The first chapter might be of less interest as it gives only an
     overview on SQL.

  -) The second chapter gives a description on much of PostgreSQL's
     features (like user defined types etc. and how to use these features)

  -) The third chapter starts with an overview of PostgreSQL's internal
     structure with focus on the stages a query has to pass (i.e. parser,
     planner/optimizer, executor). Then a detailed description of the
     implementation of the Having clause and the Intersect/Except logic is
     given.

Originally I worked on v6.3.2 but never found time enough to prepare
and post a patch. Now I applied the changes to v6.4 to get Intersect
and Except working with the new version. Chapter 3 of my documentation
deals with the changes against v6.3.2, so keep that in mind when
comparing the parts of the code printed there with the patched sources
of v6.4.

Here are some remarks on the patch. There are some things that have
still to be done but at the moment I don't have time to do them
myself. (I'm doing my military service at the moment) Sorry for that
:-(

-) I used a rewrite technique for the implementation of the Except/Intersect
   logic which rewrites the query to a semantically equivalent query before
   it is handed to the rewrite system (for views, rules etc.), planner,
   executor etc.

-) In v6.3.2 the types of the attributes of two select statements
   connected by the UNION keyword had to match 100%. In v6.4 the types
   only need to be familiar (i.e. int and float can be mixed). Since this
   feature did not exist when I worked on Intersect/Except it
   does not work correctly for Except/Intersect queries WHEN USED IN
   COMBINATION WITH UNIONS! (i.e. sometimes the wrong type is used for the
   resulting table. This is because until now the types of the attributes of
   the first select statement have been used for the resulting table.
   When Intersects and/or Excepts are used in combination with Unions it
   might happen, that the first select statement of the original query
   appears at another position in the query which will be executed. The reason
   for this is the technique used for the implementation of
   Except/Intersect which does a query rewrite!)
   NOTE: It is NOT broken for pure UNION queries and pure INTERSECT/EXCEPT
         queries!!!

-) I had to add the field intersect_clause to some data structures
   but did not find time to implement printfuncs for the new field.
   This does NOT break the debug modes but when an Except/Intersect
   is used the query debug output will be the already rewritten query.

-) Massive changes to the grammar rules for SELECT and INSERT statements
   have been necessary (see comments in gram.y and documentation for
   deatails) in order to be able to use mixed queries like
   (SELECT ... UNION (SELECT ... EXCEPT SELECT)) INTERSECT SELECT...;

-) When using UNION/EXCEPT/INTERSECT you will get:
   NOTICE: equal: "Don't know if nodes of type xxx are equal".
   I did not have  time to add comparsion support for all the needed nodes,
   but the default behaviour of the function equal met my requirements.
   I did not dare to supress this message!

   That's the reason why the regression test for union will fail: These
   messages are also included in the union.out file!

-) Somebody of you changed the union_planner() function for v6.4
   (I copied the targetlist to new_tlist and that was removed and
   replaced by a cleanup of the original targetlist). These chnages
   violated some having queries executed against views so I changed
   it back again. I did not have time to examine the differences between the
   two versions but now it works :-)
   If you want to find out, try the file queries/view_having.sql on
   both versions and compare the results . Two queries won't produce a
   correct result with your version.

regards

    Stefan
1999-01-18 00:10:17 +00:00
Vadim B. Mikheev 6beba218d7 New HeapTuple structure/interface. 1998-11-27 19:52:36 +00:00
Bruce Momjian fa1a8d6a97 OK, folks, here is the pgindent output. 1998-09-01 04:40:42 +00:00
Bruce Momjian 460b20a43f 1) Queries using the having clause on base tables should work well
now. Here some tested features, (examples included in the patch):

1.1) Subselects in the having clause 1.2) Double nested subselects
1.3) Subselects used in the where clause and in the having clause
     simultaneously 1.4) Union Selects using having 1.5) Indexes
on the base relations are used correctly 1.6) Unallowed Queries
are prevented (e.g. qualifications in the
     having clause that belong to the where clause) 1.7) Insert
into as select

2) Queries using the having clause on view relations also work
   but there are some restrictions:

2.1) Create View as Select ... Having ...; using base tables in
the select 2.1.1) The Query rewrite system:

2.1.2) Why are only simple queries allowed against a view from 2.1)
? 2.2) Select ... from testview1, testview2, ... having...; 3) Bug
in ExecMergeJoin ??


Regards Stefan
1998-07-19 05:49:26 +00:00
Bruce Momjian 6bd323c6b3 Remove un-needed braces around single statements. 1998-06-15 19:30:31 +00:00
Bruce Momjian 8eb08ae6b9 Cleanup up code. 1998-04-13 21:07:15 +00:00
Bruce Momjian c579ce0fb0 I started adding the Having Clause and it works quite fine for
sequential scans! (I think it will also work with hash, index, etc
but I did not check it out! I made some High level changes which
should work for all access methods, but maybe I'm wrong. Please
let me know.)

Now it is possible to make queries like:

select s.sname, max(p.pid), min(p.pid) from part p, supplier s
where s.sid=p.sid group by s.sname having max(pid)=6 and min(pid)=1
or avg(pid)=4;

Having does not work yet for queries that contain a subselect
statement in the Having clause, I'll try to fix this in the next
days.

If there are some bugs, please let me know, I'll start to read the
mailinglists now!

Now here is the patch against the original 6.3 version (no snapshot!!):

Stefan
1998-03-30 16:36:43 +00:00
Bruce Momjian a32450a585 pgindent run before 6.3 release, with Thomas' requested changes. 1998-02-26 04:46:47 +00:00
Vadim B. Mikheev 1a105cefbd Support for subselects.
ExecReScan for nodeAgg, nodeHash, nodeHashjoin, nodeNestloop and nodeResult.
Fixed ExecReScan for nodeMaterial.
Get rid of #ifdef INDEXSCAN_PATCH.
Get rid of ExecMarkPos and ExecRestrPos in nodeNestloop.
1998-02-13 03:26:53 +00:00