tuples with less header overhead than a regular HeapTuple, per my
recent proposal. Teach TupleTableSlot code how to deal with these.
As proof of concept, change tuplestore.c to store MinimalTuples instead
of HeapTuples. Future patches will expand the concept to other places
where it is useful.
are unnecessarily allocated on the heap rather than the stack. If the
StringInfo doesn't outlive the stack frame in which it is created,
there is no need to allocate it on the heap via makeStringInfo() --
stack allocation is faster. While it's not a big deal unless the
code is in a critical path, I don't see a reason not to save a few
cycles -- using stack allocation is not less readable.
I also cleaned up a bit of code along the way: moved variable
declarations into a more tightly-enclosing scope where possible,
fixed some pointless copying of strings in dblink, etc.
more compliant with the error message style guide. In particular,
errdetail should begin with a capital letter and end with a period,
whereas errmsg should not. I also fixed a few related issues in
passing, such as fixing the repeated misspelling of "lexeme" in
contrib/tsearch2 (per Tom's suggestion).
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
and RelationNameGetTupleDesc() as deprecated; remove uses of the
latter in the contrib library. Along the way, clean up crosstab()
code and documentation a little.
spotted by Qingqing Zhou. The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places. If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL. But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.
mode see a fresh snapshot for each command in the function, rather than
using the latest interactive command's snapshot. Also, suppress fresh
snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE
functions, instead using the snapshot taken for the most closely nested
regular query. (This behavior is only sane for read-only functions, so
the patch also enforces that such functions contain only SELECT commands.)
As per my proposal of 6-Sep-2004; I note that I floated essentially the
same proposal on 19-Jun-2002, but that discussion tailed off without any
action. Since 8.0 seems like the right place to be taking possibly
nontrivial backwards compatibility hits, let's get it done now.
>
> The patch adds missing the "libpgport.a" file to the installation under
> "install-all-headers". It is needed by some contribs. I install the
> library in "pkglibdir", but I was wondering whether it should be "libdir"?
> I was wondering also whether it would make sense to have a "libpgport.so"?
>
> It fixes various macros which are used by contrib makefiles, especially
> libpq_*dir and LDFLAGS when used under PGXS. It seems to me that they are
> needed to
>
> It adds the ability to test and use PGXS with contribs, with "make
> USE_PGXS=1". Without the macro, this is exactly as before, there should be
> no difference, esp. wrt the vpath feature that seemed broken by previous
> submission. So it should not harm anybody, and it is useful at least to me.
>
> It fixes some inconsistencies in various contrib makefiles
> (useless override, ":=" instead of "=").
Fabien COELHO
results with tuples as ordinary varlena Datums. This commit does not
in itself do much for us, except eliminate the horrid memory leak
associated with evaluation of whole-row variables. However, it lays the
groundwork for allowing composite types as table columns, and perhaps
some other useful features as well. Per my proposal of a few days ago.
Make btree index creation and initial validation of foreign-key constraints
use maintenance_work_mem rather than work_mem as their memory limit.
Add some code to guc.c to allow these variables to be referenced by their
old names in SHOW and SET commands, for backwards compatibility.
Lars Boegild Thomsen (full email below) and also corrects the regression
expected output for a recent backend message adjustment. Please apply.
Joe Conway
This was the last piece of code that took it upon itself to reset the
random number sequence --- now we only have srandom() in postmaster start,
backend start, and explicit setseed() operations.
>>Sounds like all that's needed for your case. But to be complete, in
>>addition to changing tablefunc.c we'd have to:
>>1) come up with a new function call signature that makes sense and does
>>not cause backward compatibility problems for other people
>>2) make needed changes to tablefunc.sql.in
>>3) adjust the README.tablefunc appropriately
>>4) adjust the regression test for new functionality
>>5) be sure we don't break any of the old cases
>>
>>If you want to submit a complete patch, it would be gratefully accepted
>>-- for review at least ;-)
>
> Here's the patch, at least for steps 1-3
Nabil Sayegh
Joe Conway
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.
(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
version of crosstab. This fixes a major deficiency in real-world use of
the original version. Easiest to undestand with an illustration:
Data:
-------------------------------------------------------------------
select * from cth;
id | rowid | rowdt | attribute | val
----+-------+---------------------+----------------+---------------
1 | test1 | 2003-03-01 00:00:00 | temperature | 42
2 | test1 | 2003-03-01 00:00:00 | test_result | PASS
3 | test1 | 2003-03-01 00:00:00 | volts | 2.6987
4 | test2 | 2003-03-02 00:00:00 | temperature | 53
5 | test2 | 2003-03-02 00:00:00 | test_result | FAIL
6 | test2 | 2003-03-02 00:00:00 | test_startdate | 01 March 2003
7 | test2 | 2003-03-02 00:00:00 | volts | 3.1234
(7 rows)
Original crosstab:
-------------------------------------------------------------------
SELECT * FROM crosstab(
'SELECT rowid, attribute, val FROM cth ORDER BY 1,2',4)
AS c(rowid text, temperature text, test_result text, test_startdate
text, volts text);
rowid | temperature | test_result | test_startdate | volts
-------+-------------+-------------+----------------+--------
test1 | 42 | PASS | 2.6987 |
test2 | 53 | FAIL | 01 March 2003 | 3.1234
(2 rows)
Hashed crosstab:
-------------------------------------------------------------------
SELECT * FROM crosstab(
'SELECT rowid, attribute, val FROM cth ORDER BY 1',
'SELECT DISTINCT attribute FROM cth ORDER BY 1')
AS c(rowid text, temperature int4, test_result text, test_startdate
timestamp, volts float8);
rowid | temperature | test_result | test_startdate | volts
-------+-------------+-------------+---------------------+--------
test1 | 42 | PASS | | 2.6987
test2 | 53 | FAIL | 2003-03-01 00:00:00 | 3.1234
(2 rows)
Notice that the original crosstab slides data over to the left in the
result tuple when it encounters missing data. In order to work around
this you have to be make your source sql do all sorts of contortions
(cartesian join of distinct rowid with distinct attribute; left join
that back to the real source data). The new version avoids this by
building a hash table using a second distinct attribute query.
The new version also allows for "extra" columns (see the README) and
allows the result columns to be coerced into differing datatypes if they
are suitable (as shown above).
In testing a "real-world" data set (69 distinct rowid's, 27 distinct
categories/attributes, multiple missing data points) I saw about a
5-fold improvement in execution time (from about 2200 ms old, to 440 ms
new).
I left the original version intact because: 1) BC, 2) it is probably
slightly faster if you know that you have no missing attributes.
README and regression test adjustments included. If there are no
objections, please apply.
Joe Conway
entire contents of the subplan into the tuplestore before we can return
any tuples. Instead, the tuplestore holds what we've already read, and
we fetch additional rows from the subplan as needed. Random access to
the previously-read rows works with the tuplestore, and doesn't affect
the state of the partially-read subplan. This is a step towards fixing
the problems with cursors over complex queries --- we don't want to
stick in Materialize nodes if they'll prevent quick startup for a cursor.
Create objects in public schema.
Make spacing/capitalization consistent.
Remove transaction block use for object creation.
Remove unneeded function GRANTs.
> contrib/tablefunc/tablefunc.c:connectby. But, other unmanageable error
> seems to occur even if a table has commonplace tree data(see below).
>
> I would think the patch, ancestor check, should be
>
> if (strstr(branch_delim || branchstr->data || branch_delim,
> branch_delim || current_key || branch_delim))
>
> This is my image, not a real code. However, if branchstr->data includes
> branch_delim, my image will not be perfect.
Good point. Thank you Masaru for the suggested fix.
Attached is a patch to fix the bug found by Masaru. His example now
produces:
regression=# SELECT * FROM connectby('connectby_tree', 'keyid',
'parent_keyid', '11', 0, '-') AS t(keyid int, parent_keyid int, level
int,
branch text);
keyid | parent_keyid | level | branch
-------+--------------+-------+----------
11 | | 0 | 11
10 | 11 | 1 | 11-10
111 | 11 | 1 | 11-111
1 | 111 | 2 | 11-111-1
(4 rows)
While making the patch I also realized that the "no show branch" form of
the function was not going to work very well for recursion detection.
Therefore there is now a default branch delimiter ('~') that is used
internally, for that case, to enable recursion detection to work. If
you need a different delimiter for your specific data, you will have to
use the "show branch" form of the function.
Joe Conway
contrib/tablefunc. Specifically it replaces the use of VIEWs (for needed
composite type creation) with use of CREATE TYPE. It also performs GRANT
EXECUTE ON FUNCTION foo() TO PUBLIC for all of the created functions. There
was also a cosmetic change to two regression files.
Joe Conway
> be a useful function for many users. However, I found the fact that
> if connectby_tree has the following data, connectby() tries to search the end
> of roots without knowing that the relations are infinite(-5-9-10-11-9-10-11-)
.
> I hope connectby() supports a check routine to find infinite relations.
>
>
> CREATE TABLE connectby_tree(keyid int, parent_keyid int);
> INSERT INTO connectby_tree VALUES(1,NULL);
> INSERT INTO connectby_tree VALUES(2,1);
> INSERT INTO connectby_tree VALUES(3,1);
> INSERT INTO connectby_tree VALUES(4,2);
> INSERT INTO connectby_tree VALUES(5,2);
> INSERT INTO connectby_tree VALUES(6,4);
> INSERT INTO connectby_tree VALUES(7,3);
> INSERT INTO connectby_tree VALUES(8,6);
> INSERT INTO connectby_tree VALUES(9,5);
>
> INSERT INTO connectby_tree VALUES(10,9);
> INSERT INTO connectby_tree VALUES(11,10);
> INSERT INTO connectby_tree VALUES(9,11); <-- infinite
>
The attached patch fixes the infinite recursion bug in
contrib/tablefunc/tablefunc.c:connectby found by Masaru Sugawara.
test=# SELECT * FROM connectby('connectby_tree', 'keyid',
'parent_keyid', '2', 4, '~') AS t(keyid int, parent_keyid int, level
int, branch text);
keyid | parent_keyid | level | branch
-------+--------------+-------+-------------
2 | | 0 | 2
4 | 2 | 1 | 2~4
6 | 4 | 2 | 2~4~6
8 | 6 | 3 | 2~4~6~8
5 | 2 | 1 | 2~5
9 | 5 | 2 | 2~5~9
10 | 9 | 3 | 2~5~9~10
11 | 10 | 4 | 2~5~9~10~11
(8 rows)
test=# SELECT * FROM connectby('connectby_tree', 'keyid',
'parent_keyid', '2', 5, '~') AS t(keyid int, parent_keyid int, level
int, branch text);
ERROR: infinite recursion detected
I implemented it by checking the branch string for repeated keys
(whether or not the branch is returned). The performance hit was pretty
minimal -- about 1% for a moderately complex test case (220000 record
table, 9 level tree with 3800 members).
Joe Conway
