- 08 Oct, 1999 1 commit
-
-
Tom Lane authored
and update some comments.
-
- 28 Sep, 1999 1 commit
-
-
Tom Lane authored
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...
-
- 26 Sep, 1999 1 commit
-
-
Tom Lane authored
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...
-
- 22 Aug, 1999 1 commit
-
-
Tom Lane authored
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 ...
-
- 21 Aug, 1999 1 commit
-
-
Tom Lane authored
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.
-
- 17 Jul, 1999 1 commit
-
-
Bruce Momjian authored
-
- 16 Jul, 1999 1 commit
-
-
Bruce Momjian authored
-
- 15 Jul, 1999 2 commits
-
-
Bruce Momjian authored
-
Bruce Momjian authored
-
- 12 Jun, 1999 2 commits
-
-
Bruce Momjian authored
-
Bruce Momjian authored
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
-
- 25 May, 1999 2 commits
-
-
Bruce Momjian authored
-
Bruce Momjian authored
-
- 29 Apr, 1999 1 commit
-
-
Tom Lane authored
Things are better now.
-
- 21 Mar, 1999 1 commit
-
-
Tom Lane authored
is pass-by-value.
-
- 20 Mar, 1999 2 commits
-
-
Bruce Momjian authored
-
Bruce Momjian authored
-
- 13 Feb, 1999 1 commit
-
-
Bruce Momjian authored
-
- 27 Jan, 1999 1 commit
-
-
Bruce Momjian authored
-
- 26 Jan, 1999 1 commit
-
-
Bruce Momjian authored
-
- 25 Jan, 1999 1 commit
-
-
Bruce Momjian authored
-
- 24 Jan, 1999 1 commit
-
-
Bruce Momjian authored
-
- 18 Jan, 1999 1 commit
-
-
Bruce Momjian authored
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
-
- 27 Nov, 1998 1 commit
-
-
Vadim B. Mikheev authored
-
- 01 Sep, 1998 1 commit
-
-
Bruce Momjian authored
-
- 19 Jul, 1998 1 commit
-
-
Bruce Momjian authored
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
-
- 15 Jun, 1998 1 commit
-
-
Bruce Momjian authored
-
- 13 Apr, 1998 1 commit
-
-
Bruce Momjian authored
-
- 30 Mar, 1998 1 commit
-
-
Bruce Momjian authored
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
-
- 26 Feb, 1998 1 commit
-
-
Bruce Momjian authored
-
- 13 Feb, 1998 1 commit
-
-
Vadim B. Mikheev authored
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.
-
- 31 Jan, 1998 1 commit
-
-
Bruce Momjian authored
calls.
-
- 15 Jan, 1998 4 commits
-
-
Bruce Momjian authored
-
Marc G. Fournier authored
nodeAgg.c: WARN -> NOTICE for elog parse_oper.c: was created after patch for fmgr_info, so function call wrong scan.c: regenerated for i386_solaris using flex 2.5.4 gethostname.c: required prototype for gethostname() function config.h.in: create prototype for isinfo() function isinf.c: "fake" isinf() under i386_solaris using fpclass() call...
-
PostgreSQL Daemon authored
Patch by: wieck@sapserv.debis.de (Jan Wieck) One of the design rules of PostgreSQL is extensibility. And to follow this rule means (at least for me) that there should not only be a builtin PL. Instead I would prefer a defined interface for PL implemetations.
-
Bruce Momjian authored
Pass List* of Aggregs into executor, and create needed array there. No longer need to double-processs Aggregs with second copy in Query. Fix crash when doing: select sum(x+1) from test where 1 > 0;
-
- 07 Jan, 1998 1 commit
-
-
Bruce Momjian authored
-
- 05 Jan, 1998 1 commit
-
-
Bruce Momjian authored
-
- 04 Jan, 1998 1 commit
-
-
Bruce Momjian authored
-
- 29 Dec, 1997 1 commit
-
-
Bruce Momjian authored
-