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
file. The original code probed the PGPROC array separately for each PID,
which was not good for large numbers of backends: not only is the runtime
O(N^2) but most of it is spent holding ProcArrayLock. Instead, take the
lock just once and copy the active PIDs into an array, then use qsort
and bsearch so that the lookup time is more like O(N log N).
messages, when client attempts to execute these outside a transaction (start
one) or in a failed transaction (reject message, except for COMMIT/ROLLBACK
statements which we can handle). Per report from Francisco Figueiredo Jr.
< * %Allow pooled connections to list all prepared queries
> * %Allow pooled connections to list all prepared statements
28c28
< the queries prepared in the current session.
> the statements prepared in the current session.
143c143
< o Allow a warm standby system to also allow read-only queries
> o Allow a warm standby system to also allow read-only statements
404c404
< * Add GUC to issue notice about queries that use unjoined tables
> * Add GUC to issue notice about statements that use unjoined tables
490c490
< Another idea would be to allow actual SELECT queries in a COPY.
> Another idea would be to allow actual SELECT statements in a COPY.
554c554
< o Allow function argument names to be queries from PL/PgSQL
> o Allow function argument names to be statements from PL/PgSQL
591c591
< o Improve psql's handling of multi-line queries
> o Improve psql's handling of multi-line statements
< Currently, while \e saves a single query as one entry, interactive
< queries are saved one line at a time. Ideally all queries
> Currently, while \e saves a single statement as one entry, interactive
> statements are saved one line at a time. Ideally all statements
665c665
< o Allow query results to be automatically batched to the client
> o Allow statement results to be automatically batched to the client
667c667
< Currently, all query results are transfered to the libpq
> Currently, all statement results are transfered to the libpq
672c672
< One complexity is that a query like SELECT 1/col could error
> One complexity is that a statement like SELECT 1/col could error
739c739
< * Allow queries across databases or servers with transaction
> * Allow statements across databases or servers with transaction
< inheritance, allow it to work for UPDATE and DELETE queries, and allow
< it to be used for all queries with little performance impact
> inheritance, allow it to work for UPDATE and DELETE statements, and allow
> it to be used for all statements with little performance impact
876c876
< * Consider automatic caching of queries at various levels:
> * Consider automatic caching of statements at various levels:
947c947
< a single session using multiple threads to execute a query faster.
> a single session using multiple threads to execute a statement faster.
1025c1025
< * Log queries where the optimizer row estimates were dramatically
> * Log statements where the optimizer row estimates were dramatically
1146c1146
< of result sets using new query protocol
> of result sets using new statement protocol
reduce contention for the former single LockMgrLock. Per my recent
proposal. I set it up for 16 partitions, but on a pgbench test this
gives only a marginal further improvement over 4 partitions --- we need
to test more scenarios to choose the number of partitions.
Bruce Momjian