(previously we only did = and <> correctly). Also, allow row comparisons
with any operators that are in btree opclasses, not only those with these
specific names. This gets rid of a whole lot of indefensible assumptions
about the behavior of particular operators based on their names ... though
it's still true that IN and NOT IN expand to "= ANY". The patch adds a
RowCompareExpr expression node type, and makes some changes in the
representation of ANY/ALL/ROWCOMPARE SubLinks so that they can share code
with RowCompareExpr.
I have not yet done anything about making RowCompareExpr an indexable
operator, but will look at that soon.
initdb forced due to changes in stored rules.
if (c == '\\' && cstate->line_buf.len == 0)
The problem with that is the because of the input and _output_
buffering, cstate->line_buf.len could be zero even if we are not on the
first character of a line. In fact, for a typical line, it is zero for
all characters on the line. The proper solution is to introduce a
boolean, first_char_in_line, that we set as we enter the loop and clear
once we process a character.
I have restructured the line-reading code in copy.c by:
o merging the CSV/non-CSV functions into a single function
o used macros to centralize and clarify the buffering code
o updated comments
o renamed client_encoding_only to encoding_embeds_ascii
o added a high-bit test to the encoding_embeds_ascii test for
performance
o in CSV mode, allow a backslash followed by a non-period to
continue being processed as a data value
There should be no performance impact from this patch because it is
functionally equivalent. If you apply the patch you will see copy.c is
much clearer in this area now and might suggest additional
optimizations.
I have also attached a 8.1-only patch to fix the CSV \. handling bug
with no code restructuring.
* %Make row-wise comparisons work per SQL spec
Right now, '(a, b) < (1, 2)' is processed as 'a < 1 and b < 2', but
the SQL standard requires it to be processed as a column-by-column
comparison, so the proper comparison is '(a < 1) OR (a = 1 AND b < 2)'.
- use "bool" rather than "int" for boolean variables
- use "PLy_malloc" rather than "malloc" in two places
- define "PLy_strdup", and use it rather than malloc() + strcpy() in
two places (which should have been memcpy(), anyway).
- remove a bunch of redundant parentheses from expressions that do not
need the parentheses for code clarity
#define HIGHBIT (0x80)
#define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
and removed CSIGNBIT and mapped it uses to HIGHBIT. I have also added
uses for IS_HIGHBIT_SET where appropriate. This change is
purely for code clarity.
See:
Subject: [HACKERS] bugs with certain Asian multibyte charsets
From: Tatsuo Ishii <ishii@sraoss.co.jp>
To: pgsql-hackers@postgresql.org
Date: Sat, 24 Dec 2005 18:25:33 +0900 (JST)
for more details/
differ by more than the last directory component. Instead of insisting
that they match up to the last component, accept whatever common prefix
they have, and try to replace the non-matching part of bin_path with
the non-matching part of target_path in the actual executable's path.
In one way this is tighter than the old code, because it insists on
a match to the part of bin_path we want to substitute for, rather than
blindly stripping one directory component from the executable's path.
Per gripe from Martin Pitt and subsequent discussion.
Also make the code more robust by searching for target encoding
in the internal charset map.
Problem reported by Sagi Bashari on 2005/12/21.
See "[BUGS] BUG #2120: Crash when doing UTF8<->ISO_8859_8 encoding conversion"
on pgsql-bugs list for more details.
equal: if strcoll claims two strings are equal, check it with strcmp, and
sort according to strcmp if not identical. This fixes inconsistent
behavior under glibc's hu_HU locale, and probably under some other locales
as well. Also, take advantage of the now-well-defined behavior to speed up
texteq, textne, bpchareq, bpcharne: they may as well just do a bitwise
comparison and not bother with strcoll at all.
NOTE: affected databases may need to REINDEX indexes on text columns to be
sure they are self-consistent.
Fix example for day and hours interval subtraction for new computation
method.
Update interval examples to display zero seconds, which is our default.
Backpatch to 8.1.X.
Per my recent proposal. I ended up basing the implementation on the
existing mechanism for enforcing valid join orders of IN joins --- the
rules for valid outer-join orders are somewhat similar.
< * Allow star join optimizations
<
< While our bitmap scan allows multiple indexes to be joined to get
< to heap rows, a star joins allows multiple dimension _tables_ to
< be joined to index into a larger main fact table. The join is
< usually performed by either creating a cartesian product of all
< the dimmension tables and doing a single join on that product or
< using subselects to create bitmaps of each dimmension table match
< and merge the bitmaps to perform the join on the fact table. Some
< of these algorithms might be patented.
< * Flush cached query plans when the dependent objects change or
< when the cardinality of parameters changes dramatically
> * Flush cached query plans when the dependent objects change,
> when the cardinality of parameters changes dramatically, or
> when new ANALYZE statistics are available
Drake:
< and merge the bitmaps to perform the join on the fact table.
> and merge the bitmaps to perform the join on the fact table. Some
> of these algorithms might be patented.
* Allow star join optimizations
While our bitmap scan allows multiple indexes to be joined to get
to heap rows, a star joins allows multiple dimension _tables_ to
be joined to index into a larger main fact table. The join is
usually performed by either creating a cartesian product of all
the dimmension tables and doing a single join on that product or
using subselects to create bitmaps of each dimmension table match
and merge the bitmaps to perform the join on the fact table.
< * Flush cached query plans when the dependent objects change
> * Flush cached query plans when the dependent objects change or
> when the cardinality of parameters changes dramatically
Bruce Momjian
Tom Lane
Andrew Dunstan
Peter Eisentraut
Neil Conway
Tatsuo Ishii
Teodor Sigaev