2009年7月 3日

[installer 1985] postgresql-8.4.0

postgresql-8.4.0 出ています。

☆ postgresql-8.4.0
http://www.postgresql.org/
ftp://ftp.postgresql.org/pub/source/v8.4.0/postgresql-8.4.0.tar.gz

Release 8.4

Release date: 2009-07-01
__________________________________________________________________

Overview

After many years of development, PostgreSQL has become feature-complete
in many areas. This release shows a targeted approach to adding
features (e.g., authentication, monitoring, space reuse), and adds
capabilities defined in the later SQL standards. The major areas of
enhancement are:

* Windowing Functions
* Common Table Expressions and Recursive Queries
* Default and variadic parameters for functions
* Parallel Restore
* Column Permissions
* Per-database locale settings
* Improved hash indexes
* Improved join performance for EXISTS and NOT EXISTS queries
* Easier-to-use Warm Standby
* Automatic sizing of the Free Space Map
* Visibility Map (greatly reduces vacuum overhead for slowly-changing
tables)
* Version-aware psql (backslash commands work against older servers)
* Support SSL certificates for user authentication
* Per-function runtime statistics
* Easy editing of functions in psql
* New contrib modules: pg_stat_statements, auto_explain, citext,
btree_gin

The above items are explained in more detail in the sections below.
__________________________________________________________________

Migration to Version 8.4

A dump/restore using pg_dump is required for those wishing to migrate
data from any previous release.

Observe the following incompatibilities:
__________________________________________________________________

General

* Use 64-bit integer datetimes by default (Neil Conway)
Previously this was selected by configure's
"--enable-integer-datetimes" option. To retain the old behavior,
build with "--disable-integer-datetimes".
* Remove ipcclean utility command (Bruce)
The utility only worked on a few platforms. Users should use their
operating system tools instead.
__________________________________________________________________

Server Settings

* Change default setting for log_min_messages to warning (previously
it was notice) to reduce log file volume (Tom)
* Change default setting for max_prepared_transactions to zero
(previously it was 5) (Tom)
* Make debug_print_parse, debug_print_rewritten, and debug_print_plan
output appear at LOG message level, not DEBUG1 as formerly (Tom)
* Make debug_pretty_print default to on (Tom)
* Remove explain_pretty_print parameter (no longer needed) (Tom)
* Make log_temp_files settable by superusers only, like other logging
options (Simon Riggs)
* Remove automatic appending of the epoch timestamp when no % escapes
are present in log_filename (Robert Haas)
This change was made because some users wanted a fixed log
filename, for use with an external log rotation tool.
* Remove log_restartpoints from "recovery.conf"; instead use
log_checkpoints (Simon)
* Remove krb_realm and krb_server_hostname; these are now set in
"pg_hba.conf" instead (Magnus)
* There are also significant changes in "pg_hba.conf", as described
below.
__________________________________________________________________

Queries

* Change "TRUNCATE" and "LOCK" to apply to child tables of the
specified table(s) (Peter)
These commands now accept an ONLY option that prevents processing
child tables; this option must be used if the old behavior is
needed.
* "SELECT DISTINCT" and UNION/INTERSECT/EXCEPT no longer always
produce sorted output (Tom)
Previously, these types of queries always removed duplicate rows by
means of Sort/Unique processing (i.e., sort then remove adjacent
duplicates). Now they can be implemented by hashing, which will not
produce sorted output. If an application relied on the output being
in sorted order, the recommended fix is to add an ORDER BY clause.
As a short-term workaround, the previous behavior can be restored
by disabling enable_hashagg, but that is a very
performance-expensive fix. SELECT DISTINCT ON never uses hashing,
however, so its behavior is unchanged.
* Force child tables to inherit CHECK constraints from parents (Alex
Hunsaker, Nikhil Sontakke, Tom)
Formerly it was possible to drop such a constraint from a child
table, allowing rows that violate the constraint to be visible when
scanning the parent table. This was deemed inconsistent, as well as
contrary to SQL standard.
* Disallow negative LIMIT or OFFSET values, rather than treating them
as zero (Simon)
* Disallow "LOCK TABLE" outside a transaction block (Tom)
Such an operation is useless because the lock would be released
immediately.
* Sequences now contain an additional start_value column (Zoltan
Boszormenyi)
This supports "ALTER SEQUENCE ... RESTART".
__________________________________________________________________

Functions and Operators

* Make numeric zero raised to a fractional power return 0, rather
than throwing an error, and make numeric zero raised to the zero
power return 1, rather than error (Bruce)
This matches the longstanding float8 behavior.
* Allow unary minus of floating-point values to produce minus zero
(Tom)
The changed behavior is more IEEE-standard compliant.
* Throw an error if an escape character is the last character in a
LIKE pattern (i.e., it has nothing to escape) (Tom)
Previously, such an escape character was silently ignored, thus
possibly masking application logic errors.
* Remove ~=~ and ~<>~ operators formerly used for LIKE index
comparisons (Tom)
Pattern indexes now use the regular equality operator.
* xpath() now passes its arguments to libxml without any changes
(Andrew)
This means that the XML argument must be a well-formed XML
document. The previous coding attempted to allow XML fragments, but
it did not work well.
* Make xmlelement() format attribute values just like content values
(Peter)
Previously, attribute values were formatted according to the normal
SQL output behavior, which is sometimes at odds with XML rules.
* Rewrite memory management for libxml-using functions (Tom)
This change should avoid some compatibility problems with use of
libxml in PL/Perl and other add-on code.
* Adopt a faster algorithm for hash functions (Kenneth Marshall,
based on work of Bob Jenkins)
Many of the built-in hash functions now deliver different results
on little-endian and big-endian platforms.
__________________________________________________________________

Temporal Functions and Operators

* DateStyle no longer controls interval output formatting; instead
there is a new variable IntervalStyle (Ron Mayer)
* Improve consistency of handling of fractional seconds in timestamp
and interval output (Ron Mayer)
This may result in displaying a different number of fractional
digits than before, or rounding instead of truncating.
* Make to_char()'s localized month/day names depend on LC_TIME, not
LC_MESSAGES (Euler Taveira de Oliveira)
* Cause to_date() and to_timestamp() to more consistently report
errors for invalid input (Brendan Jurd)
Previous versions would often ignore or silently misread input that
did not match the format string. Such cases will now result in an
error.
* Fix to_timestamp() to not require upper/lower case matching for
meridian (AM/PM) and era (BC/AD) format designations (Brendan Jurd)
For example, input value ad now matches the format string AD.
__________________________________________________________________

Changes

Below you will find a detailed account of the changes between
PostgreSQL 8.4 and the previous major release.
__________________________________________________________________

Performance

* Improve optimizer statistics calculations (Jan Urbanski, Tom)
In particular, estimates for full-text-search operators are greatly
improved.
* Allow "SELECT DISTINCT" and UNION/INTERSECT/EXCEPT to use hashing
(Tom)
This means that these types of queries no longer automatically
produce sorted output.
* Create explicit concepts of semi-joins and anti-joins (Tom)
This work formalizes our previous ad-hoc treatment of IN (SELECT
...) clauses, and extends it to EXISTS and NOT EXISTS clauses. It
should result in significantly better planning of EXISTS and NOT
EXISTS queries. In general, logically equivalent IN and EXISTS
clauses should now have similar performance, whereas previously IN
often won.
* Improve optimization of sub-selects beneath outer joins (Tom)
Formerly, a sub-select or view could not be optimized very well if
it appeared within the nullable side of an outer join and contained
non-strict expressions (for instance, constants) in its result
list.
* Improve the performance of text_position() and related functions by
using Boyer-Moore-Horspool searching (David Rowley)
This is particularly helpful for long search patterns.
* Reduce I/O load of writing the statistics collection file by
writing the file only when requested (Martin Pihlak)
* Improve performance for bulk inserts (Robert Haas, Simon)
* Increase the default value of default_statistics_target from 10 to
100 (Greg Sabino Mullane, Tom)
The maximum value was also increased from 1000 to 10000.
* Perform constraint_exclusion checking by default in queries
involving inheritance or UNION ALL (Tom)
A new constraint_exclusion setting, partition, was added to specify
this behavior.
* Allow I/O read-ahead for bitmap index scans (Greg Stark)
The amount of read-ahead is controlled by effective_io_concurrency.
This feature is available only if the kernel has posix_fadvise()
support.
* Inline simple set-returning SQL functions in FROM clauses (Richard
Rowell)
* Improve performance of multi-batch hash joins by providing a
special case for join key values that are especially common in the
outer relation (Bryce Cutt, Ramon Lawrence)
* Reduce volume of temporary data in multi-batch hash joins by
suppressing "physical tlist" optimization (Michael Henderson, Ramon
Lawrence)
* Avoid waiting for idle-in-transaction sessions during "CREATE INDEX
CONCURRENTLY" (Simon)
* Improve performance of shared cache invalidation (Tom)
__________________________________________________________________

Server

Settings

* Convert many "postgresql.conf" settings to enumerated values so
that pg_settings can display the valid values (Magnus)
* Add cursor_tuple_fraction parameter to control the fraction of a
cursor's rows that the planner assumes will be fetched (Robert
Hell)
* Allow underscores in the names of custom variable classes in
"postgresql.conf" (Tom)
__________________________________________________________________

Authentication and security

* Remove support for the (insecure) crypt authentication method
(Magnus)
This effectively obsoletes pre-PostgreSQL 7.2 client libraries, as
there is no longer any non-plaintext password method that they can
use.
* Support regular expressions in "pg_ident.conf" (Magnus)
* Allow Kerberos/GSSAPI parameters to be changed without restarting
the postmaster (Magnus)
* Support SSL certificate chains in server certificate file (Andrew
Gierth)
Including the full certificate chain makes the client able to
verify the certificate without having all intermediate CA
certificates present in the local store, which is often the case
for commercial CAs.
* Report appropriate error message for combination of MD5
authentication and db_user_namespace enabled (Bruce)
__________________________________________________________________

pg_hba.conf

* Change all authentication options to use name=value syntax (Magnus)
This makes incompatible changes to the ldap, pam and ident
authentication methods. All "pg_hba.conf" entries with these
methods need to be rewritten using the new format.
* Remove the ident sameuser option, instead making that behavior the
default if no usermap is specified (Magnus)
* Allow a usermap parameter for all external authentication methods
(Magnus)
Previously a usermap was only supported for ident authentication.
* Add clientcert option to control requesting of a client certificate
(Magnus)
Previously this was controlled by the presence of a root
certificate file in the server's data directory.
* Add cert authentication method to allow *user* authentication via
SSL certificates (Magnus)
Previously SSL certificates could only verify that the client had
access to a certificate, not authenticate a user.
* Allow krb5, gssapi and sspi realm and krb5 host settings to be
specified in "pg_hba.conf" (Magnus)
These override the settings in "postgresql.conf".
* Add include_realm parameter for krb5, gssapi, and sspi methods
(Magnus)
This allows identical usernames from different realms to be
authenticated as different database users using usermaps.
* Parse "pg_hba.conf" fully when it is loaded, so that errors are
reported immediately (Magnus)
Previously, most errors in the file wouldn't be detected until
clients tried to connect, so an erroneous file could render the
system unusable. With the new behavior, if an error is detected
during reload then the bad file is rejected and the postmaster
continues to use its old copy.
* Show all parsing errors in "pg_hba.conf" instead of aborting after
the first one (Selena Deckelmann)
* Support ident authentication over Unix-domain sockets on Solaris
(Garick Hamlin)
__________________________________________________________________

Continuous Archiving

* Provide an option to pg_start_backup() to force its implied
checkpoint to finish as quickly as possible (Tom)
The default behavior avoids excess I/O consumption, but that is
pointless if no concurrent query activity is going on.
* Make pg_stop_backup() wait for modified WAL files to be archived
(Simon)
This guarantees that the backup is valid at the time
pg_stop_backup() completes.
* When archiving is enabled, rotate the last WAL segment at shutdown
so that all transactions can be archived immediately (Guillaume
Smet, Heikki)
* Delay "smart" shutdown while a continuous archiving base backup is
in progress (Laurenz Albe)
* Cancel a continuous archiving base backup if "fast" shutdown is
requested (Laurenz Albe)
* Allow "recovery.conf" boolean variables to take the same range of
string values as "postgresql.conf" boolean variables (Bruce)
__________________________________________________________________

Monitoring

* Add pg_conf_load_time() to report when the PostgreSQL configuration
files were last loaded (George Gensure)
* Add pg_terminate_backend() to safely terminate a backend (the
SIGTERM signal works also) (Tom, Bruce)
While it's always been possible to SIGTERM a single backend, this
was previously considered unsupported; and testing of the case
found some bugs that are now fixed.
* Add ability to track user-defined functions' call counts and
runtimes (Martin Pihlak)
Function statistics appear in a new system view,
pg_stat_user_functions. Tracking is controlled by the new parameter
track_functions.
* Allow specification of the maximum query string size in
pg_stat_activity via new track_activity_query_size parameter
(Thomas Lee)
* Increase the maximum line length sent to syslog, in hopes of
improving performance (Tom)
* Add read-only configuration variables segment_size, wal_block_size,
and wal_segment_size (Bernd Helmle)
* When reporting a deadlock, report the text of all queries involved
in the deadlock to the server log (Itagaki Takahiro)
* Add pg_stat_get_activity(pid) function to return information about
a specific process id (Magnus)
* Allow the location of the server's statistics file to be specified
via stats_temp_directory (Magnus)
This allows the statistics file to be placed in a RAM-resident
directory to reduce I/O requirements. On startup/shutdown, the file
is copied to its traditional location ($PGDATA/global/) so it is
preserved across restarts.
__________________________________________________________________

Queries

* Add support for WINDOW functions (Hitoshi Harada)
* Add support for WITH clauses (CTEs), including WITH RECURSIVE
(Yoshiyuki Asaba, Tatsuo Ishii, Tom)
* Add "TABLE" command (Peter)
TABLE tablename is a SQL standard short-hand for SELECT * FROM
tablename.
* Allow AS to be optional when specifying a "SELECT" (or RETURNING)
column output label (Hiroshi Saito)
This works so long as the column label is not any PostgreSQL
keyword; otherwise AS is still needed.
* Support set-returning functions in "SELECT" result lists even for
functions that return their result via a tuplestore (Tom)
In particular, this means that functions written in PL/PgSQL and
other PL languages can now be called this way.
* Support set-returning functions in the output of aggregation and
grouping queries (Tom)
* Allow "SELECT FOR UPDATE"/SHARE to work on inheritance trees (Tom)
* Add infrastructure for SQL/MED (Martin Pihlak, Peter)
There are no remote or external SQL/MED capabilities yet, but this
change provides a standardized and future-proof system for managing
connection information for modules like "dblink" and "plproxy".
* Invalidate cached plans when referenced schemas, functions,
operators, or operator classes are modified (Martin Pihlak, Tom)
This improves the system's ability to respond to on-the-fly DDL
changes.
* Allow comparison of composite types and allow arrays of anonymous
composite types (Tom)
This allows constructs such as row(1, 1.1) = any (array[row(7,
7.7), row(1, 1.0)]). This is particularly useful in recursive
queries.
* Add support for Unicode string literal and identifier
specifications using code points, e.g. U&'d\0061t\+000061' (Peter)
* Reject \000 in string literals and "COPY" data (Tom)
Previously, this was accepted but had the effect of terminating the
string contents.
* Improve the parser's ability to report error locations (Tom)
An error location is now reported for many semantic errors, such as
mismatched datatypes, that previously could not be localized.
__________________________________________________________________

TRUNCATE

* Support statement-level ON TRUNCATE triggers (Simon)
* Add RESTART/CONTINUE IDENTITY options for "TRUNCATE TABLE" (Zoltan
Boszormenyi)
The start value of a sequence can be changed by "ALTER SEQUENCE
START WITH".
* Allow "TRUNCATE tab1, tab1" to succeed (Bruce)
* Add a separate "TRUNCATE" permission (Robert Haas)
__________________________________________________________________

EXPLAIN

* Make "EXPLAIN VERBOSE" show the output columns of each plan node
(Tom)
Previously "EXPLAIN VERBOSE" output an internal representation of
the query plan. (That behavior is now available via
debug_print_plan.)
* Make "EXPLAIN" identify subplans and initplans with individual
labels (Tom)
* Make "EXPLAIN" honor debug_print_plan (Tom)
* Allow "EXPLAIN" on "CREATE TABLE AS" (Peter)
__________________________________________________________________

LIMIT/OFFSET

* Allow sub-selects in LIMIT and OFFSET (Tom)
* Add SQL-standard syntax for LIMIT/OFFSET capabilities (Peter)
To wit, OFFSET num {ROW|ROWS} FETCH {FIRST|NEXT} [num] {ROW|ROWS}
ONLY.
__________________________________________________________________

Object Manipulation

* Add support for column-level privileges (Stephen Frost, KaiGai
Kohei)
* Refactor multi-object "DROP" operations to reduce the need for
CASCADE (Alex Hunsaker)
For example, if table B has a dependency on table A, the command
DROP TABLE A, B no longer requires the CASCADE option.
* Fix various problems with concurrent "DROP" commands by ensuring
that locks are taken before we begin to drop dependencies of an
object (Tom)
* Improve reporting of dependencies during "DROP" commands (Tom)
* Add WITH [NO] DATA clause to "CREATE TABLE AS", per the SQL
standard (Peter, Tom)
* Add support for user-defined I/O conversion casts (Heikki)
* Allow "CREATE AGGREGATE" to use an internal transition datatype
(Tom)
* Add LIKE clause to "CREATE TYPE" (Tom)
This simplifies creation of data types that use the same internal
representation as an existing type.
* Allow specification of the type category and "preferred" status for
user-defined base types (Tom)
This allows more control over the coercion behavior of user-defined
types.
* Allow "CREATE OR REPLACE VIEW" to add columns to the end of a view
(Robert Haas)
__________________________________________________________________

ALTER

* Add "ALTER TYPE RENAME" (Petr Jelinek)
* Add "ALTER SEQUENCE ... RESTART" (with no parameter) to reset a
sequence to its initial value (Zoltan Boszormenyi)
* Modify the "ALTER TABLE" syntax to allow all reasonable
combinations for tables, indexes, sequences, and views (Tom)
This change allows the following new syntaxes:
+ "ALTER SEQUENCE OWNER TO"
+ "ALTER VIEW ALTER COLUMN SET/DROP DEFAULT"
+ "ALTER VIEW OWNER TO"
+ "ALTER VIEW SET SCHEMA"
There is no actual new functionality here, but formerly you had to
say "ALTER TABLE" to do these things, which was confusing.
* Add support for the syntax "ALTER TABLE ... ALTER COLUMN ... SET
DATA TYPE" (Peter)
This is SQL-standard syntax for functionality that was already
supported.
* Make "ALTER TABLE SET WITHOUT OIDS" rewrite the table to physically
remove OID values (Tom)
Also, add "ALTER TABLE SET WITH OIDS" to rewrite the table to add
OIDs.
__________________________________________________________________

Database Manipulation

* Improve reporting of "CREATE"/"DROP"/"RENAME DATABASE" failure when
uncommitted prepared transactions are the cause (Tom)
* Make LC_COLLATE and LC_CTYPE into per-database settings (Radek
Strnad, Heikki)
This makes collation similar to encoding, which was always
configurable per database.
* Improve checks that the database encoding, collation (LC_COLLATE),
and character classes (LC_CTYPE) match (Heikki, Tom)
Note in particular that a new database's encoding and locale
settings can be changed only when copying from template0. This
prevents possibly copying data that doesn't match the settings.
* Add "ALTER DATABASE SET TABLESPACE" to move a database to a new
tablespace (Guillaume Lelarge, Bernd Helmle)
__________________________________________________________________

Utility Operations

* Add a VERBOSE option to the "CLUSTER" command and clusterdb (Jim
Cox)
* Decrease memory requirements for recording pending trigger events
(Tom)
__________________________________________________________________

Indexes

* Dramatically improve the speed of building and accessing hash
indexes (Tom Raney, Shreya Bhargava)
This allows hash indexes to be sometimes faster than btree indexes.
However, hash indexes are still not crash-safe.
* Make hash indexes store only the hash code, not the full value of
the indexed column (Xiao Meng)
This greatly reduces the size of hash indexes for long indexed
values, improving performance.
* Implement fast update option for GIN indexes (Teodor, Oleg)
This option greatly improves update speed at a small penalty in
search speed.
* xxx_pattern_ops indexes can now be used for simple equality
comparisons, not only for LIKE (Tom)
__________________________________________________________________

Full Text Indexes

* Remove the requirement to use @@@ when doing GIN weighted lookups
on full text indexes (Tom, Teodor)
The normal @@ text search operator can be used instead.
* Add an optimizer selectivity function for @@ text search operations
(Jan Urbanski)
* Allow prefix matching in full text searches (Teodor Sigaev, Oleg
Bartunov)
* Support multi-column GIN indexes (Teodor Sigaev)
* Improve support for Nepali language and Devanagari alphabet
(Teodor)
__________________________________________________________________

VACUUM

* Track free space in separate per-relation "fork" files (Heikki)
Free space discovered by "VACUUM" is now recorded in "*_fsm" files,
rather than in a fixed-sized shared memory area. The max_fsm_pages
and max_fsm_relations settings have been removed, greatly
simplifying administration of free space management.
* Add a visibility map to track pages that do not require vacuuming
(Heikki)
This allows "VACUUM" to avoid scanning all of a table when only a
portion of the table needs vacuuming. The visibility map is stored
in per-relation "fork" files.
* Add vacuum_freeze_table_age parameter to control when "VACUUM"
should ignore the visibility map and do a full table scan to freeze
tuples (Heikki)
* Track transaction snapshots more carefully (Alvaro)
This improves "VACUUM"'s ability to reclaim space in the presence
of long-running transactions.
* Add ability to specify per-relation autovacuum and TOAST parameters
in "CREATE TABLE" (Alvaro, Euler Taveira de Oliveira)
Autovacuum options used to be stored in a system table.
* Add --freeze option to vacuumdb (Bruce)
__________________________________________________________________

Data Types

* Add a CaseSensitive option for text search synonym dictionaries
(Simon)
* Improve the precision of NUMERIC division (Tom)
* Add basic arithmetic operators for int2 with int8 (Tom)
This eliminates the need for explicit casting in some situations.
* Allow UUID input to accept an optional hyphen after every fourth
digit (Robert Haas)
* Allow on/off as input for the boolean data type (Itagaki Takahiro)
* Allow spaces around NaN in the input string for type numeric (Sam
Mason)
__________________________________________________________________

Temporal Data Types

* Reject year 0 BC and years 000 and 0000 (Tom)
Previously these were interpreted as 1 BC. (Note: years 0 and 00
are still assumed to be the year 2000.)
* Include SGT (Singapore time) in the default list of known time zone
abbreviations (Tom)
* Support infinity and -infinity as values of type date (Tom)
* Make parsing of interval literals more standard-compliant (Tom, Ron
Mayer)
For example, INTERVAL '1' YEAR now does what it's supposed to.
* Allow interval fractional-seconds precision to be specified after
the second keyword, for SQL standard compliance (Tom)
Formerly the precision had to be specified after the keyword
interval. (For backwards compatibility, this syntax is still
supported, though deprecated.) Data type definitions will now be
output using the standard format.
* Support the IS0 8601 interval syntax (Ron Mayer, Kevin Grittner)
For example, INTERVAL 'P1Y2M3DT4H5M6.7S' is now supported.
* Add IntervalStyle parameter which controls how interval values are
output (Ron Mayer)
Valid values are: postgres, postgres_verbose, sql_standard,
iso_8601. This setting also controls the handling of negative
interval input when only some fields have positive/negative
designations.
* Improve consistency of handling of fractional seconds in timestamp
and interval output (Ron Mayer)
__________________________________________________________________

Arrays

* Improve the handling of casts applied to ARRAY[] constructs, such
as ARRAY[...]::integer[] (Brendan Jurd)
Formerly PostgreSQL attempted to determine a data type for the
ARRAY[] construct without reference to the ensuing cast. This could
fail unnecessarily in many cases, in particular when the ARRAY[]
construct was empty or contained only ambiguous entries such as
NULL. Now the cast is consulted to determine the type that the
array elements must be.
* Make SQL-syntax ARRAY dimensions optional to match the SQL standard
(Peter)
* Add array_ndims() to return the number of dimensions of an array
(Robert Haas)
* Add array_length() to return the length of an array for a specified
dimension (Jim Nasby, Robert Haas, Peter Eisentraut)
* Add aggregate function array_agg(), which returns all aggregated
values as a single array (Robert Haas, Jeff Davis, Peter)
* Add unnest(), which converts an array to individual row values
(Tom)
This is the opposite of array_agg().
* Add array_fill() to create arrays initialized with a value (Pavel
Stehule)
* Add generate_subscripts() to simplify generating the range of an
array's subscripts (Pavel Stehule)
__________________________________________________________________

Wide-Value Storage (TOAST)

* Consider TOAST compression on values as short as 32 bytes
(previously 256 bytes) (Greg Stark)
* Require 25% minimum space savings before using TOAST compression
(previously 20% for small values and any-savings-at-all for large
values) (Greg)
* Improve TOAST heuristics for rows that have a mix of large and
small toastable fields, so that we prefer to push large values out
of line and don't compress small values unnecessarily (Greg, Tom)
__________________________________________________________________

Functions

* Document that setseed() allows values from -1 to 1 (not just 0 to
1), and enforce the valid range (Kris Jurka)
* Add server-side function lo_import(filename, oid) (Tatsuo)
* Add quote_nullable(), which behaves like quote_literal() but
returns the string NULL for a null argument (Brendan Jurd)
* Improve full text search headline() function to allow extracting
several fragments of text (Sushant Sinha)
* Add suppress_redundant_updates_trigger() trigger function to avoid
overhead for non-data-changing updates (Andrew)
* Add div(numeric, numeric) to perform numeric division without
rounding (Tom)
* Add timestamp and timestamptz versions of generate_series()
(Hitoshi Harada)
__________________________________________________________________

Object Information Functions

* Implement current_query() for use by functions that need to know
the currently running query (Tomas Doran)
* Add pg_get_keywords() to return a list of the parser keywords (Dave
Page)
* Add pg_get_functiondef() to see a function's definition (Abhijit
Menon-Sen)
* Allow the second argument of pg_get_expr() to be zero when
deparsing an expression that does not contain variables (Tom)
* Modify pg_relation_size() to use regclass (Heikki)
pg_relation_size(data_type_name) no longer works.
* Add boot_val and reset_val columns to pg_settings output (Greg
Smith)
* Add source file name and line number columns to pg_settings output
for variables set in a configuration file (Magnus, Alvaro)
For security reasons, these columns are only visible to superusers.
* Add support for CURRENT_CATALOG, CURRENT_SCHEMA, SET CATALOG, SET
SCHEMA (Peter)
These provide SQL-standard syntax for existing features.
* Add pg_typeof() which returns the data type of any value (Brendan
Jurd)
* Make version() return information about whether the server is a 32-
or 64-bit binary (Bruce)
* Fix the behavior of information schema columns is_insertable_into
and is_updatable to be consistent (Peter)
* Improve the behavior of information schema datetime_precision
columns (Peter)
These columns now show zero for date columns, and 6 (the default
precision) for time, timestamp, and interval without a declared
precision, rather than showing null as formerly.
* Convert remaining builtin set-returning functions to use OUT
parameters (Jaime Casanova)
This makes it possible to call these functions without specifying a
column list: pg_show_all_settings(), pg_lock_status(),
pg_prepared_xact(), pg_prepared_statement(), pg_cursor()
* Make pg_*_is_visible() and has_*_privilege() functions return NULL
for invalid OIDs, rather than reporting an error (Tom)
* Extend has_*_privilege() functions to allow inquiring about the OR
of multiple privileges in one call (Stephen Frost, Tom)
* Add has_column_privilege() and has_any_column_privilege() functions
(Stephen Frost, Tom)
__________________________________________________________________

Function Creation

* Support variadic functions (functions with a variable number of
arguments) (Pavel Stehule)
Only trailing arguments can be optional, and they all must be of
the same data type.
* Support default values for function arguments (Pavel Stehule)
* Add "CREATE FUNCTION ... RETURNS TABLE" clause (Pavel Stehule)
* Allow SQL-language functions to return the output of an
"INSERT"/"UPDATE"/"DELETE" RETURNING clause (Tom)
__________________________________________________________________

PL/PgSQL Server-Side Language

* Support EXECUTE USING for easier insertion of data values into a
dynamic query string (Pavel Stehule)
* Allow looping over the results of a cursor using a FOR loop (Pavel
Stehule)
* Support RETURN QUERY EXECUTE (Pavel Stehule)
* Improve the RAISE command (Pavel Stehule)
+ Support DETAIL and HINT fields
+ Support specification of the SQLSTATE error code
+ Support an exception name parameter
+ Allow RAISE without parameters in an exception block to
re-throw the current error
* Allow specification of SQLSTATE codes in EXCEPTION lists (Pavel
Stehule)
This is useful for handling custom SQLSTATE codes.
* Support the CASE statement (Pavel Stehule)
* Make "RETURN QUERY" set the special FOUND and "GET DIAGNOSTICS"
ROW_COUNT variables (Pavel Stehule)
* Make "FETCH" and "MOVE" set the "GET DIAGNOSTICS" ROW_COUNT
variable (Andrew Gierth)
* Make "EXIT" without a label always exit the innermost loop (Tom)
Formerly, if there were a BEGIN block more closely nested than any
loop, it would exit that block instead. The new behavior matches
Oracle(TM) and is also what was previously stated by our own
documentation.
* Make processing of string literals and nested block comments match
the main SQL parser's processing (Tom)
In particular, the format string in "RAISE" now works the same as
any other string literal, including being subject to
standard_conforming_strings. This change also fixes other cases in
which valid commands would fail when standard_conforming_strings is
on.
* Avoid memory leakage when the same function is called at varying
exception-block nesting depths (Tom)
__________________________________________________________________

Client Applications

* Fix pg_ctl restart to preserve command-line arguments (Bruce)
* Add -w/--no-password option that prevents password prompting in all
utilities that have a -W/--password option (Peter)
* Remove "-q" (quiet) option of createdb, createuser, dropdb,
dropuser (Peter)
These options have had no effect since PostgreSQL 8.3.
__________________________________________________________________

psql

* Remove verbose startup banner; now just suggest help (Joshua Drake)
* Make help show common backslash commands (Greg Sabino Mullane)
* Add \pset format wrapped mode to wrap output to the screen width,
or file/pipe output too if \pset columns is set (Bryce Nesbitt)
* Allow all supported spellings of boolean values in "\pset", rather
than just on and off (Bruce)
Formerly, any string other than "off" was silently taken to mean
true. psql will now complain about unrecognized spellings (but
still take them as true).
* Use the pager for wide output (Bruce)
* Require a space between a one-letter backslash command and its
first argument (Bernd Helmle)
This removes a historical source of ambiguity.
* Improve tab completion support for schema-qualified and quoted
identifiers (Greg Sabino Mullane)
* Add optional on/off argument for "\timing" (David Fetter)
* Display access control rights on multiple lines (Brendan Jurd,
Andreas Scherbaum)
* Make "\l" show database access privileges (Andrew Gilligan)
* Make "\l+" show database sizes, if permissions allow (Andrew
Gilligan)
* Add the "\ef" command to edit function definitions (Abhijit
Menon-Sen)
__________________________________________________________________

psql \d* commands

* Make "\d*" commands that do not have a pattern argument show system
objects only if the S modifier is specified (Greg Sabino Mullane,
Bruce)
The former behavior was inconsistent across different variants of
"\d", and in most cases it provided no easy way to see just user
objects.
* Improve "\d*" commands to work with older PostgreSQL server
versions (back to 7.4), not only the current server version
(Guillaume Lelarge)
* Make "\d" show foreign-key constraints that reference the selected
table (Kenneth D'Souza)
* Make "\d" on a sequence show its column values (Euler Taveira de
Oliveira)
* Add column storage type and other relation options to the "\d+"
display (Gregory Stark, Euler Taveira de Oliveira)
* Show relation size in "\dt+" output (Dickson S. Guedes)
* Show the possible values of enum types in "\dT+" (David Fetter)
* Allow "\dC" to accept a wildcard pattern, which matches either
datatype involved in the cast (Tom)
* Add a function type column to "\df"'s output, and add options to
list only selected types of functions (David Fetter)
* Make "\df" not hide functions that take or return type cstring
(Tom)
Previously, such functions were hidden because most of them are
datatype I/O functions, which were deemed uninteresting. The new
policy about hiding system functions by default makes this wart
unnecessary.
__________________________________________________________________

pg_dump

* Add a --no-tablespaces option to pg_dump/pg_dumpall/pg_restore so
that dumps can be restored to clusters that have non-matching
tablespace layouts (Gavin Roy)
* Remove "-d" and "-D" options from pg_dump and pg_dumpall (Tom)
These options were too frequently confused with the option to
select a database name in other PostgreSQL client applications. The
functionality is still available, but you must now spell out the
long option name "--inserts" or "--column-inserts".
* Remove "-i"/"--ignore-version" option from pg_dump and pg_dumpall
(Tom)
Use of this option does not throw an error, but it has no effect.
This option was removed because the version checks are necessary
for safety.
* Disable statement_timeout during dump and restore (Joshua Drake)
* Add pg_dump/pg_dumpall option "--lock-wait-timeout" (David Gould)
This allows dumps to fail if unable to acquire a shared lock within
the specified amount of time.
* Reorder pg_dump --data-only output to dump tables referenced by
foreign keys before the referencing tables (Tom)
This allows data loads when foreign keys are already present. If
circular references make a safe ordering impossible, a NOTICE is
issued.
* Allow pg_dump, pg_dumpall, and pg_restore to use a specified role

投稿者 xml-rpc : 2009年7月 3日 16:41
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