Release date: 2009-07-01
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.
A dump/restore using pg_dump is required for those wishing to migrate data from any previous release.
Observe the following incompatibilities:
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.
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.
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
.
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.
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
.
Below you will find a detailed account of the changes between PostgreSQL 8.4 and the previous major release.
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)
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)
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)
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)
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.
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
.
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 OID
s.
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)
Add a VERBOSE
option to the CLUSTER
command and
clusterdb (Jim Cox)
Decrease memory requirements for recording pending trigger events (Tom)
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)
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)
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)
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)
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)
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)
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)
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)
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)
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)
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.
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)
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.
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 (Benedek László)
Allow pg_restore to use multiple concurrent connections to do the restore (Andrew)
The number of concurrent connections is controlled by the option
--jobs
. This is supported only for custom-format archives.
Allow the OID
to be specified when importing a large
object, via new function lo_import_with_oid()
(Tatsuo)
Add “events” support (Andrew Chernow, Merlin Moncure)
This adds the ability to register callbacks to manage private
data associated with PGconn
and PGresult
objects.
Improve error handling to allow the return of multiple error messages as multi-line error reports (Magnus)
Make PQexecParams()
and related functions return
PGRES_EMPTY_QUERY
for an empty query (Tom)
They previously returned PGRES_COMMAND_OK
.
Document how to avoid the overhead of WSACleanup()
on Windows (Andrew Chernow)
Do not rely on Kerberos tickets to determine the default database username (Magnus)
Previously, a Kerberos-capable build of libpq would use the principal name from any available Kerberos ticket as default database username, even if the connection wasn't using Kerberos authentication. This was deemed inconsistent and confusing. The default username is now determined the same way with or without Kerberos. Note however that the database username must still match the ticket when Kerberos authentication is used.
Fix certificate validation for SSL connections (Magnus)
libpq now supports verifying both the certificate
and the name of the server when making SSL
connections. If a root certificate is not available to use for
verification, SSL connections will fail. The
sslmode
parameter is used to enable certificate
verification and set the level of checking.
The default is still not to do any verification, allowing connections
to SSL-enabled servers without requiring a root certificate on the
client.
Support wildcard server certificates (Magnus)
If a certificate CN starts with *
, it will
be treated as a wildcard when matching the hostname, allowing the
use of the same certificate for multiple servers.
Allow the file locations for client certificates to be specified (Mark Woodward, Alvaro, Magnus)
Add a PQinitOpenSSL
function to allow greater control
over OpenSSL/libcrypto initialization (Andrew Chernow)
Make libpq unregister its OpenSSL callbacks when no database connections remain open (Bruce, Magnus, Russell Smith)
This is required for applications that unload the libpq library, otherwise invalid OpenSSL callbacks will remain.
Add localization support for messages (Euler Taveira de Oliveira)
ecpg parser is now automatically generated from the server parser (Michael)
Previously the ecpg parser was hand-maintained.
Add support for single-use plans with out-of-line parameters (Tom)
Add new SPI_OK_REWRITTEN
return code for
SPI_execute()
(Heikki)
This is used when a command is rewritten to another type of command.
Remove unnecessary inclusions from executor/spi.h
(Tom)
SPI-using modules might need to add some #include
lines if they were depending on spi.h
to include
things for them.
Update build system to use Autoconf 2.61 (Peter)
Require GNU bison for source code builds (Peter)
This has effectively been required for several years, but now there is no infrastructure claiming to support other parser tools.
Add pg_config --htmldir
option
(Peter)
Pass float4
by value inside the server (Zoltan
Boszormenyi)
Add configure option
--disable-float4-byval
to use the old behavior.
External C functions that use old-style (version 0) call convention
and pass or return float4
values will be broken by this
change, so you may need the configure option if you
have such functions and don't want to update them.
Pass float8
, int8
, and related datatypes
by value inside the server on 64-bit platforms (Zoltan Boszormenyi)
Add configure option
--disable-float8-byval
to use the old behavior.
As above, this change might break old-style external C functions.
Add configure options --with-segsize
,
--with-blocksize
, --with-wal-blocksize
,
--with-wal-segsize
(Zdenek Kotala, Tom)
This simplifies build-time control over several constants that
previously could only be changed by editing
pg_config_manual.h
.
Allow threaded builds on Solaris 2.5 (Bruce)
Use the system's getopt_long()
on Solaris
(Zdenek Kotala, Tom)
This makes option processing more consistent with what Solaris users expect.
Add support for the Sun Studio compiler on Linux (Julius Stroffek)
Append the major version number to the backend gettext
domain, and the soname
major version number to
libraries' gettext domain (Peter)
This simplifies parallel installations of multiple versions.
Add support for code coverage testing with gcov (Michelle Caisse)
Allow out-of-tree builds on Mingw and Cygwin (Richard Evans)
Fix the use of Mingw as a cross-compiling source platform (Peter)
Support 64-bit time zone data files (Heikki)
This adds support for daylight saving time (DST) calculations beyond the year 2038.
Deprecate use of platform's time_t
data type (Tom)
Some platforms have migrated to 64-bit time_t
, some have
not, and Windows can't make up its mind what it's doing. Define
pg_time_t
to have the same meaning as time_t
,
but always be 64 bits (unless the platform has no 64-bit integer type),
and use that type in all module APIs and on-disk data formats.
Fix bug in handling of the time zone database when cross-compiling (Richard Evans)
Link backend object files in one step, rather than in stages (Peter)
Improve gettext support to allow better translation of plurals (Peter)
Add message translation support to the PL languages (Alvaro, Peter)
Add more DTrace probes (Robert Lor)
Enable DTrace support on macOS Leopard and other non-Solaris platforms (Robert Lor)
Simplify and standardize conversions between C strings and
text
datums, by providing common functions for the purpose
(Brendan Jurd, Tom)
Clean up the include/catalog/
header files so that
frontend programs can include them without including
postgres.h
(Zdenek Kotala)
Make name
char-aligned, and suppress zero-padding of
name
entries in indexes (Tom)
Recover better if dynamically-loaded code executes exit()
(Tom)
Add a hook to let plug-ins monitor the executor (Itagaki Takahiro)
Add a hook to allow the planner's statistics lookup behavior to be overridden (Simon Riggs)
Add shmem_startup_hook()
for custom shared memory
requirements (Tom)
Replace the index access method amgetmulti
entry point
with amgetbitmap
, and extend the API for
amgettuple
to support run-time determination of
operator lossiness (Heikki, Tom, Teodor)
The API for GIN and GiST opclass consistent
functions
has been extended as well.
Add support for partial-match searches in GIN indexes (Teodor Sigaev, Oleg Bartunov)
Replace pg_class
column reltriggers
with boolean relhastriggers
(Simon)
Also remove unused pg_class
columns
relukeys
, relfkeys
, and
relrefs
.
Add a relistemp
column to pg_class
to ease identification of temporary tables (Tom)
Move platform FAQs into the main documentation (Peter)
Prevent parser input files from being built with any conflicts (Peter)
Add support for the KOI8U
(Ukrainian) encoding
(Peter)
Add Japanese message translations (Japan PostgreSQL Users Group)
This used to be maintained as a separate project.
Fix problem when setting LC_MESSAGES
on
MSVC-built systems (Hiroshi Inoue, Hiroshi
Saito, Magnus)
Add contrib/auto_explain
to automatically run
EXPLAIN
on queries exceeding a specified duration
(Itagaki Takahiro, Tom)
Add contrib/btree_gin
to allow GIN indexes to
handle more datatypes (Oleg, Teodor)
Add contrib/citext
to provide a case-insensitive,
multibyte-aware text data type (David Wheeler)
Add contrib/pg_stat_statements
for server-wide
tracking of statement execution statistics (Itagaki Takahiro)
Add duration and query mode options to contrib/pgbench
(Itagaki Takahiro)
Make contrib/pgbench
use table names
pgbench_accounts
, pgbench_branches
,
pgbench_history
, and pgbench_tellers
,
rather than just accounts
, branches
,
history
, and tellers
(Tom)
This is to reduce the risk of accidentally destroying real data by running pgbench.
Fix contrib/pgstattuple
to handle tables and
indexes with over 2 billion pages (Tatsuhito Kasahara)
In contrib/fuzzystrmatch
, add a version of the
Levenshtein string-distance function that allows the user to
specify the costs of insertion, deletion, and substitution
(Volkan Yazici)
Make contrib/ltree
support multibyte encodings
(laser)
Enable contrib/dblink
to use connection information
stored in the SQL/MED catalogs (Joe Conway)
Improve contrib/dblink
's reporting of errors from
the remote server (Joe Conway)
Make contrib/dblink
set client_encoding
to match the local database's encoding (Joe Conway)
This prevents encoding problems when communicating with a remote database that uses a different encoding.
Make sure contrib/dblink
uses a password supplied
by the user, and not accidentally taken from the server's
.pgpass
file (Joe Conway)
This is a minor security enhancement.
Add fsm_page_contents()
to contrib/pageinspect
(Heikki)
Modify get_raw_page()
to support free space map
(*_fsm
) files. Also update
contrib/pg_freespacemap
.
Add support for multibyte encodings to contrib/pg_trgm
(Teodor)
Rewrite contrib/intagg
to use new
functions array_agg()
and unnest()
(Tom)
Make contrib/pg_standby
recover all available WAL before
failover (Fujii Masao, Simon, Heikki)
To make this work safely, you now need to set the new
recovery_end_command
option in recovery.conf
to clean up the trigger file after failover. pg_standby
will no longer remove the trigger file itself.
contrib/pg_standby
's -l
option is now a no-op,
because it is unsafe to use a symlink (Simon)