yet, but at least we can give a better error message:
regression=> select count(distinct f1) from int4_tbl;
ERROR: aggregate(DISTINCT ...) is not implemented yet
instead of 'parser: parse error at or near distinct'.
This one should work much better than the one I sent in previously. The
functionality is the same, but the patch was missing one file resulting
in
the compilation failing. The docs also received a minor fix.
Peter Eisentraut Sernanders väg 10:115
table defaults or rules: translate them to a function call so that
parse_coerce doesn't reduce them to a date or time constant immediately.
Also, eliminate a lot of redundancy in the expression grammar by
defining a new nonterminal com_expr, which contains all the productions
that can be shared by a_expr and b_expr.
subselects can only appear on the righthand side of a binary operator.
That's still true for quantified predicates like x = ANY (SELECT ...),
but a subselect that delivers a single result can now appear anywhere
in an expression. This is implemented by changing EXPR_SUBLINK sublinks
to represent just the (SELECT ...) expression, without any 'left hand
side' or combining operator --- so they're now more like EXISTS_SUBLINK.
To handle the case of '(x, y, z) = (SELECT ...)', I added a new sublink
type MULTIEXPR_SUBLINK, which acts just like EXPR_SUBLINK used to.
But the grammar will only generate one for a multiple-left-hand-side
row expression.
The following patch extends the COMMENT ON functionality to the
rest of the database objects beyond just tables, columns, and views. The
grammer of the COMMENT ON statement now looks like:
COMMENT ON [
[ DATABASE | INDEX | RULE | SEQUENCE | TABLE | TYPE | VIEW ] <objname>
|
COLUMN <relation>.<attribute> |
AGGREGATE <aggname> <aggtype> |
FUNCTION <funcname> (arg1, arg2, ...) |
OPERATOR <op> (leftoperand_typ rightoperand_typ) |
TRIGGER <triggername> ON relname>
Mike Mascari
(mascarim@yahoo.com)
>From the ORACLE 7 SQL Language Reference Manual:
-----------------------------------------------------
COMMENT
Purpose:
To add a comment about a table, view, snapshot, or
column into the data dictionary.
Prerequisites:
The table, view, or snapshot must be in your own
schema
or you must have COMMENT ANY TABLE system privilege.
Syntax:
COMMENT ON [ TABLE table ] |
[ COLUMN table.column] IS 'text'
You can effectively drop a comment from the database
by setting it to the empty string ''.
-----------------------------------------------------
Example:
COMMENT ON TABLE workorders IS
'Maintains base records for workorder information';
COMMENT ON COLUMN workorders.hours IS
'Number of hours the engineer worked on the task';
to drop a comment:
COMMENT ON COLUMN workorders.hours IS '';
The current patch will simply perform the insert into
pg_description, as per the TODO. And, of course, when
the table is dropped, any comments relating to it
or any of its attributes are also dropped. I haven't
looked at the ODBC source yet, but I do know from
an ODBC client standpoint that the standard does
support the notion of table and column comments.
Hopefully the ODBC driver is already fetching these
values from pg_description, but if not, it should be
trivial.
Hope this makes the grade,
Mike Mascari
(mascarim@yahoo.com)
mentioned in FROM but not elsewhere in the query: such tables should be
joined over anyway. Aside from being more standards-compliant, this allows
removal of some very ugly hacks for COUNT(*) processing. Also, allow
HAVING clause without aggregate functions, since SQL does. Clean up
CREATE RULE statement-list syntax the same way Bruce just fixed the
main stmtmulti production.
CAUTION: addition of a field to RangeTblEntry nodes breaks stored rules;
you will have to initdb if you have any rules.
expressions in CREATE TABLE. There is no longer an emasculated expression
syntax for these things; it's full a_expr for constraints, and b_expr
for defaults (unfortunately the fact that NOT NULL is a part of the
column constraint syntax causes a shift/reduce conflict if you try a_expr.
Oh well --- at least parenthesized boolean expressions work now). Also,
stored expression for a column default is not pre-coerced to the column
type; we rely on transformInsertStatement to do that when the default is
actually used. This means "f1 datetime default 'now'" behaves the way
people usually expect it to.
BTW, all the support code is now there to implement ALTER TABLE ADD
CONSTRAINT and ALTER TABLE ADD COLUMN with a default value. I didn't
actually teach ALTER TABLE to call it, but it wouldn't be much work.
not just C, so that ISCACHABLE attribute can be specified for user-defined
functions. Get rid of ParamString node type, which wasn't actually being
generated by gram.y anymore, even though define.c thought that was what
it was getting. Clean up minor bug in dfmgr.c (premature heap_close).
Implements the CREATE CONSTRAINT TRIGGER and SET CONSTRAINTS commands.
TODO:
Generic builtin trigger procedures
Automatic execution of appropriate CREATE CONSTRAINT... at CREATE TABLE
Support of new trigger type in pg_dump
Swapping of huge # of events to disk
Jan
functions. One problem that I have encountered with the function
manager is that it does not allow the user to define type conversion
functions that convert between user types. For instance if mytype1,
mytype2, and mytype3 are three Postgresql user types, and if I wish to
define Postgresql conversion functions like
I run into problems, because the Postgresql dynamic loader would look
for a single link symbol, mytype3, for both pieces of object code. If
I just change the name of one of the Postgresql functions (to make the
symbols distinct), the automatic type conversion that Postgresql uses,
for example, when matching operators to arguments no longer finds the
type conversion function.
The solution that I propose, and have implemented in the attatched
patch extends the CREATE FUNCTION syntax as follows. In the first case
above I use the link symbol mytype2_to_mytype3 for the link object
that implements the first conversion function, and define the
Postgresql operator with the following syntax
The patch includes changes to the parser to include the altered
syntax, changes to the ProcedureStmt node in nodes/parsenodes.h,
changes to commands/define.c to handle the extra information in the AS
clause, and changes to utils/fmgr/dfmgr.c that alter the way that the
dynamic loader figures out what link symbol to use. I store the
string for the link symbol in the prosrc text attribute of the pg_proc
table which is currently unused in rows that reference dynamically
loaded
functions.
Bernie Frankpitt
optimizer rather than parser. This has many advantages, such as not
getting fooled by chance uses of operator names ~ and ~~ (the operators
are identified by OID now), and not creating useless comparison operations
in contexts where the comparisons will not actually be used as indexquals.
The new code also recognizes exact-match LIKE and regex patterns, and
produces an = indexqual instead of >= and <=.
This change does NOT fix the problem with non-ASCII locales: the code
still doesn't know how to generate an upper bound indexqual for non-ASCII
collation order. But it's no worse than before, just the same deficiency
in a different place...
Also, dike out loc_restrictinfo fields in Plan nodes. These were doing
nothing useful in the absence of 'expensive functions' optimization,
and they took a considerable amount of processing to fill in.
support, but which the grammar was accepting. Also, fix several bugs
having to do with failure to copy fields up from a subselect to a select
or insert node.
creates a reduce/reduce conflict, which I resolved by changing the
'AexprConst -> Typename Sconst' rule to 'AexprConst -> SimpleTypename Sconst'.
In other words, a subscripted type declaration can't be used in that
syntax any longer. This seems a small price to pay for not having to
qualify subscripted columns anymore.
Other cleanups: rename res_target_list to update_target_list, and remove
productions for variants that are not legal in an UPDATE target list;
rename res_target_list2 to plain target_list; delete position_expr
in favor of using b_expr in that production; merge opt_indirection
into attr nonterminal, since there are no places where an unsubscripted
attr is wanted; fix typos in Param support; change case_arg so that
an arbitrary a_expr is allowed, not only a column name.
a non-leading % would be put into the >=/<= patterns. Also, repair
longstanding confusion about whether %% means a literal %%. The SQL92
doesn't say any such thing, and textlike() knows that, but gram.y didn't.
SelectStmt and CursorStmt tried to parse FOR UPDATE ... / FOR READ ONLY.
Cursor now checks that it is read only by looking at forUpdate of Query.
SelectStmt handles FOR READ ONLY too.
Jan
and lock syntax as fully parsed tokens.
Two keywords for isolation are non-reserved SQL92
(COMMITTED, SERIALIZABLE).
All other new keywords are non-reserved Postgres (not SQL92)
(ACCESS, EXCLUSIVE, MODE, SHARE).
Add syntax to allow CREATE [GLOBAL|LOCAL] TEMPORARY TABLE, throwing an
error if GLOBAL is specified.
been applied. The patches are in the .tar.gz attachment at the end:
varchar-array.patch this patch adds support for arrays of bpchar() and
varchar(), which where always missing from postgres.
These datatypes can be used to replace the _char4,
_char8, etc., which were dropped some time ago.
block-size.patch this patch fixes many errors in the parser and other
program which happen with very large query statements
(> 8K) when using a page size larger than 8192.
This patch is needed if you want to submit queries
larger than 8K. Postgres supports tuples up to 32K
but you can't insert them because you can't submit
queries larger than 8K. My patch fixes this problem.
The patch also replaces all the occurrences of `8192'
and `1<<13' in the sources with the proper constants
defined in include files. You should now never find
8192 hardwired in C code, just to make code clearer.
--
Massimo Dal Zotto
records using a sub form, i.e. entering a new order/orderlines or master
and
detail tables. The problem is caused by a SQL statement that Access97
makes
involving NULL. The syntax that fails is "column_name" = NULL. The
following attachment was provided by -Jose'-. It contains a very small
enhancement to gram.y that will allow Access97 to work properly with sub
forms. Can this enhancement be added to release 6.5?
<<gram.patch>>
Thanks, Michael
Ok. I made patches replacing all of "#if FALSE" or "#if 0" to "#ifdef
NOT_USED" for current. I have tested these patches in that the
postgres binaries are identical.
I search in the planner for the '\xFF' appending.
Finally I found in MakeIndexable() in gram.y
Attach a patch which removes the "<=" test in USE_LOCALE,
might make some queries a bit slower for us "locale-heads",
BUT correct result is more important.
regards,
--
-----------------
Göran Thyni
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
destructions in 6.4 source using purify.
(1) parser/gram.y:fmtId()
It writes n+3 bytes into n+1 byte-long memory area if mixed case or
non-ascii identifiers given.
(2) catalog/index.c:
ATTRIBUTE_TUPLE_SIZE bytes are allocated but
sizeof(FormData_pg_attribute) bytes are written. Note that
ATTRIBUTE_TUPLE_SIZE is smaller than
sizeof(FormData_pg_attribute). (for example, on solaris 2.6,
Tatsuo Ishii
parameters. With it applied a function like
CREATE FUNCTION getname(oid8, int4) RETURNS name AS
'SELECT typname FROM pg_type WHERE oid = $1[$2]'
LANGUAGE 'sql';
is possible. Mainly I need this to enable array references in
expressions for PL/pgSQL. Complete regression test ran O.K.
Jan
Add "timestamp" to list of tokens in keywords.c.
Before, TIMESTAMP WITH TIME ZONE did not actually parser.
Reorder token lists to be more alphabetical.
Remove ARCHIVE keyword which was deprecated in v6.3.
Change DEFAULT NULL to send back a NULL pointer
rather than a string "NULL". This seems to work, where sending
the string led to type conversion problems (and probably the wrong
thing anyway).
> these patches define the UNLISTEN sql command. The code already
> existed but it was unknown to the parser. Now it can be used
> like the listen command.
> You must make clean and delete gram.c and parser.h before make.
if MULTIBYTE is not enabled. So be sure to run initdb.
o these patches are made against the latest source tree (after
Bruce's massive patch, I think) BTW, I noticed that after running
regression, the oid field of pg_type seems disappeared.
regression=> select oid from pg_type; ERROR: attribute
'oid' not found
this happens after the constraints test. This occures with/without
my patches. strange...
o pg_database_mb.h, pg_class_mb.h, pg_attribute_mb.h are no longer
used, and shoud be removed.
o GetDatabaseInfo() in utils/misc/database.c removed (actually in
#ifdef 0). seems nobody uses.
t-ishii@sra.co.jp
in constraint clauses.
IN and NOT IN only allow constaints, not subselects.
Jose' Soares' new reference docs pointed out the discrepency.
Updating the docs too...
I have attached a patch to allow GROUP BY and/or ORDER BY function or
expressions. Note worthy items:
1. The expression or function need not be in the target list.
Example:
SELECT name FROM foo GROUP BY lower(name);
2. Simplified the grammar to use expressions only.
3. Cleaned up earlier patch in this area to make use of existing
utility functions.
3. Reduced some of the members in the SortGroupBy parse node. The
original data members were redundant with the new expression node.
(MUST do a "make clean" now)
4. Added a new parse node "JoinUsing". The JOIN USING clause was
overloading this SortGroupBy structure. With the afore mentioned
reduction of members, the two clauses lost all their commonality.
5. A bug still exist where, if a function or expression is GROUPed BY,
and an aggregate function does not include a attribute from the
expression or function, the backend crashes. (or something like
that) The bug pre-dates this patch. Example:
SELECT lower(a) AS lowcase, count(b) FROM foo GROUP BY lowcase;
*** BOOM ***
--Also when not in target list
SELECT count(b) FROM foo GROUP BY lower(a);
*** BOOM AGAIN ***
As Bruce mentioned, this is due to the conflict among changes we made.
Included patches should fix the problem(I changed all MB to
MULTIBYTE). Please let me know if you have further problem.
P.S. I did not include pathces to configure and gram.c to save the
file size(configure.in and gram.y modified).
From: t-ishii@sra.co.jp
Attached are patches to enhance the multi-byte support. (patches are
against 7/18 snapshot)
* determine encoding at initdb/createdb rather than compile time
Now initdb/createdb has an option to specify the encoding. Also, I
modified the syntax of CREATE DATABASE to accept encoding option. See
README.mb for more details.
For this purpose I have added new column "encoding" to pg_database.
Also pg_attribute and pg_class are changed to catch up the
modification to pg_database. Actually I haved added pg_database_mb.h,
pg_attribute_mb.h and pg_class_mb.h. These are used only when MB is
enabled. The reason having separate files is I couldn't find a way to
use ifdef or whatever in those files. I have to admit it looks
ugly. No way.
* support for PGCLIENTENCODING when issuing COPY command
commands/copy.c modified.
* support for SQL92 syntax "SET NAMES"
See gram.y.
* support for LATIN2-5
* add UNICODE regression test case
* new test suite for MB
New directory test/mb added.
* clean up source files
Basic idea is to have MB's own subdirectory for easier maintenance.
These are include/mb and backend/utils/mb.
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
Used in the generic "CREATE xxx" parsing.
Do some automatic type conversion for inserts from other columns.
Previous trouble with "resjunk" regression test remains for now.
Check for and properly ignore FOREIGN KEY column constraints
(already had fixed same for table constraints).
Define USER as synonym for CURRENT_USER per SQL92 specs
(no longer allowed as bare column name, sorry).
Re-enable HAVING clause but no fixes elsewhere yet.
Make "char" type a synonum for "char(1)" (actually implemented as bpchar).
Compress/compact row-style subselect and operator definitions
(cut out ~140 lines of code with no change in functionality).
Save string type if specified for DEFAULT clause handling.
Enough for now...
and TIMEZONE_MINUTE but don't introduce until v6.4.
Fix SET TIMEZONE LOCAL to pass null pointer
rather than older "default" string.
Fix handling of NULL pointer returns from FOREIGN KEY clauses
which are currently ignored.
Allow START as a table/column name.
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
Make "TABLE" optional in "LOCK TABLE" command
and "... INTO TABLE..." clause.
Explicitly parse CREATE SEQUENCE options to allow a negative integer
as an argument; this is an artifact of unary minus handling in scan.l.
Add "PASSWORD" as an allowed column identifier.
These fixes will require a "make clean install" but not a dump/reload.
seems that my last post didn't make it through. That's good
since the diff itself didn't covered the renaming of
pg_user.h to pg_shadow.h and it's new content.
Here it's again. The complete regression test passwd with
only some float diffs. createuser and destroyuser work.
pg_shadow cannot be read by ordinary user.
Use explicit tokens to decode CREATE TRIGGER clauses.
Allow ROW and STATEMENT as column identifiers.
Fix CAST syntax to require parens per SQL92 spec.
Define TypeId to allow correct translation of type names in CREATE FUNCTION
and other statements. Need to do this without looking up defined type
names because CREATE FUNCTION can specify undefined (new) types.
Define UserId to complete removal of "Id" generic entity.
Define xlateSqlFunc() to convert SQL92 CHARACTER_LENGTH() and CHAR_LENGTH()
functions to calls to length().
Define func_name parser entity for contexts requiring a function name.
Have xlateSqlType() translate "float" to "float8".
surrounded by parentheses (but not all are meaningful).
Remove unused keywords ACL, APPEND, MERGE.
Requires a "make clean" to recompile all code since keyword numeric
assignments have changed with keyword removal.
varchar length.
Cleans up code so attlen is always length.
Removed varchar() hack added earlier.
Will fix bug in selecting varchar() fields, and varchar() can be
variable length.
and from SELECT ... INTO ... support code.
Allow NOT, IS NULL, IS NOT NULL in constraints.
Define unionall boolean flag in SubSelect structure.
Implement row descriptors: (a, b, c) = (x, y, z).
Change IS TRUE, IS FALSE, etc. to expressions using "=" rather than
function calls to istrue() or isfalse() to allow optimization.
Force type for TRUE and FALSE to bool.
Formerly allowed only single arguments.
Declare column constraints using the usual list mechanism rather
than explicit itemized lists.
Remove NOTNULL from default clause syntax (retain "NOT NULL").
NOTNULL is not SQL92; eventually remove it from expressions too?
Move ISNULL, NOTNULL to Postgres-specific token declarations.
Fix up tabs and indenting on new CREATE USER commands.
to NOTICE messages so that execution proceeds rather than halting.
These clauses are ignored as stated in the messages.
Allow NOT NULL UNIQUE syntax (both were allowed individually before).
Allow Postgres-style casting ("::") of non-constants.
Support SQL92 syntax for type coersion of strings (type 'typeval').
Example: "DATETIME 'now'". This works only for string constants and can
not replace the CAST and ::type syntax which behave identically in this
context.
Implement SET keyword = DEFAULT and SET TIME ZONE DEFAULT.
Re-enable JOIN= option in CREATE OPERATOR statement (damaged for v6.2).
Allow more SQL and/or Postgres reserved words as column identifiers
or, if there are shift/reduce problems, at least as column labels.
CURRENT_USER.
Add syntax for primary and foreign keys.
Change optional syntax in CREATE INDEX to avoid parsing conflict with
TIMESTAMP WITH TIME ZONE data type (use USING <class> rather than WITH...).
Decouple various categories of data type syntax to allow the most possible
non-ambiguous extensions to SQL92 for column names and labels. This should
make the parser a bit more understandable, or at least easier to find
where and how the data types are handled.
Support syntax for IN and EXISTS clauses with subselects.
Support SQL92 syntax for IS TRUE/IS FALSE/IS NOT TRUE/IS NOT FALSE.
Add SQL/92 types decimal and numeric (temporary for syntax support).
These types need more support in the backend to be really implemented,
and the parser will need to be changed at that time.
Adjust limits on precision parameters for FLOAT(p) to match IEEE-compliant
arithmetic. Perhaps these limits should be processor-specific or obtained
from system include files instead.
Add parsing for UNION and outer JOINs.
Implement SQL92 "WITH TIME ZONE".
Allow some reserved words as identifiers and column labels.
Clean up indentation and "orphan spaces and tabs".
To: pgsql-patches@postgreSQL.org
Subject: [PATCHES] DROP AGGREGATE gram.y typo...
Somehow I dropped a comma in the gram.y part (line 129) of my
patch for drop aggregate. Here's a correct patch for gram.y.
PS. I hope I got the right comma, manually applied :) (scrappy)
Subject: Re: [PATCHES] SET DateStyle patches
On Tue, 22 Apr 1997, Thomas Lockhart wrote:
> Some more patches! These (try to) finish implementing SET variable TO value
> for "DateStyle" (changed the name from simply "date" to be more descriptive).
> This is based on code from Martin and Bruce (?), which was easy to modify.
> The syntax is
>
> SET DateStyle TO 'iso'
> SET DateStyle TO 'postgres'
> SET DateStyle TO 'sql'
> SET DateStyle TO 'european'
> SET DateStyle TO 'noneuropean'
> SET DateStyle TO 'us' (same as "noneuropean")
> SET DateStyle TO 'default' (current same as "postgres,us")
>
> ("european" is just compared for the first 4 characters, and "noneuropean"
> is compared for the first 7 to allow less typing).
>
> Multiple arguments are allowed, so SET datestyle TO 'sql,euro' is valid.
>
> My mods also try to implement "SHOW variable" and "RESET variable", but
> that part just core dumps at the moment. I would guess that my errors
> are obvious to someone who knows what they are doing with the parser stuff,
> so if someone (Bruce and/or Martin??) could have it do the right thing
> we will have a more complete set of what we need.
>
> Also, I would like to have a floating point precision global variable to
> implement "SET precision TO 10" and perhaps "SET precision TO 10,2" for
> float8 and float4, but I don't know how to do that for integer types rather
> than strings. If someone is fixing the SHOW and RESET code, perhaps they can
> add some hooks for me to do the floats while they are at it.
>
> I've left some remnants of variable structures in the source code which
> I did not use in the interests of getting something working for v6.1.
> We'll have time to clean things up for the next release...
Subject: [HACKERS] Patch: SET var TO 'val'
Here is a patch that adds a "SET variable TO 'somevalue'" capability
to the parser, and then calls the SetPGVariable() function (which does
just issue a elog(NOTICE) to see whether it works).
That's the framework for adding timezone/date format/language/...
stuff.
Changes:
* Unique index capability works using the syntax 'create unique
index'.
* Duplicate OID's in the system tables are removed. I put
little scripts called 'duplicate_oids' and 'find_oid' in
include/catalog that help to find and remove duplicate OID's.
I also moved 'unused_oids' from backend/catalog to
include/catalog, since it has to be in the same directory
as the include files in order to work.
* The backend tries converting the name of a function or aggregate
to all lowercase if the original name given doesn't work (mostly
for compatibility with ODBC).
* You can 'SELECT NULL' to your heart's content.
* I put my _bt_updateitem fix in instead, which uses
_bt_insertonpg so that even if the new key is so big that
the page has to be split, everything still works.
* All literal references to system catalog OID's have been
replaced with references to define'd constants from the catalog
header files.
* I added a couple of node copy functions. I think this was a
preliminary attempt to get rules to work.
It adds a WITH OIDS option to the copy command, which allows
dumping and loading of oids.
If a copy command tried to load in an oid that is greater than
its current system max oid, the system max oid is incremented. No
checking is done to see if other backends are running and have cached
oids.
pg_dump as its first step when using the -o (oid) option, will
copy in a dummy row to set the system max oid value so as rows are
loaded in, they are certain to be lower than the system oid.
pg_dump now creates indexes at the end to speed loading
Submitted by: Bruce Momjian <maillist@candle.pha.pa.us>
This patch forces postgres95 to assume any floating-point value is a
float8. It removes the requirement that you cast all floating-point
constants to float8.
We can remove alot of casts in the regression test after we are sure
this works.
If I have missed anything, would someone let me know. I have tested
inserts of floating-point values into float8 fields, and it worked well.
Casting the number to float4 showed the same precision loss as previous
uncast values showed.
Submitted by: Bruce Momjian <maillist@candle.pha.pa.us>
I've enclosed two patches. The first affects Solaris compilability. The
bug stems from netdb.h (where MAXHOSTNAMELEN is defined on a stock
system). If the user has installed the header files from BIND 4.9.x,
there will be no definition of MAXHOSTNAMELEN. The patch will, if all
else fails, try to include <arpa/nameser.h> and set MAXHOSTNAMELEN to
MAXDNAME, which is 256 (just like MAXHOSTNAMELEN on a stock system).
The second patch adds aliases for "ISNULL" to "IS NULL" and likewise for
"NOTNULL" to "IS NOT NULL". I have not removed the postgres specific
ISNULL and NOTNULL. I noticed this on the TODO list, and figured it would
be easy to remove.
The full semantics are:
[ expression IS NULL ]
[ expression IS NOT NULL ]
--Jason
Submitted by: Jason Wright <jason@oozoo.vnet.net>
Previously Postgres95 wouldn't accept 'order by' clauses with fields
referred to as '<table>.<field>', e.g.:
select t1.field1, t2.field2 from table1 t1, table2 t2
order by t2.field2;
This syntax is required by the ODBC SQL spec.
Submitted by: Dan McGuirk <mcguirk@indirect.com>
While a normal SELECT statement can contain a GROUP BY clause, a cursor
declaration cannot. This was not the case in PG-1.0. Was there a good
reason why this was changed? Are cursors being phased out? Is there any way
to get data with just a SELECT (and without a DECLARE CURSOR ...)?
The patch below seems to fix things. If anyone can see a problem with it,
please let me know. Thanks.
Submitted by: David Smith <dasmith@perseus.tufts.edu>
