Release date: 2005-11-08
Major changes in this release:
Access to the shared buffer cache was identified as a significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The buffer manager has also been changed to use a “clock sweep” replacement policy.
In previous releases, only a single index could be used to do
lookups on a table. With this feature, if a query has
WHERE tab.col1 = 4 and tab.col2 = 9
, and there is
no multicolumn index on col1
and col2
,
but there is an index on col1
and another on
col2
, it is possible to search both indexes and
combine the results in memory, then do heap fetches for only
the rows matching both the col1
and
col2
restrictions. This is very useful in
environments that have a lot of unstructured queries where it
is impossible to create indexes that match all possible access
conditions. Bitmap scans are useful even with a single index,
as they reduce the amount of random access needed; a bitmap
index scan is efficient for retrieving fairly large fractions
of the complete table, whereas plain index scans are not.
Two-phase commit allows transactions to be "prepared" on several
computers, and once all computers have successfully prepared
their transactions (none failed), all transactions can be
committed. Even if a machine crashes after a prepare, the
prepared transaction can be committed after the machine is
restarted. New syntax includes PREPARE TRANSACTION
and
COMMIT/ROLLBACK PREPARED
. A new system view
pg_prepared_xacts
has also been added.
Roles are a combination of users and groups. Like users, they can have login capability, and like groups, a role can have other roles as members. Roles basically remove the distinction between users and groups. For example, a role can:
Have login capability (optionally)
Own objects
Hold access permissions for database objects
Inherit permissions from other roles it is a member of
Once a user logs into a role, she obtains capabilities of
the login role plus any inherited roles, and can use
SET ROLE
to switch to other roles she is a member of.
This feature is a generalization of the SQL standard's concept of
roles.
This change also replaces pg_shadow
and
pg_group
by new role-capable catalogs
pg_authid
and pg_auth_members
. The old
tables are redefined as read-only views on the new role tables.
MIN()
and
MAX()
(Tom)
In previous releases, the only way to use an index for
MIN()
or MAX()
was to rewrite the
query as SELECT col FROM tab ORDER BY col LIMIT 1
.
Index usage now happens automatically.
/contrib/pg_autovacuum
into the main server
(Alvaro)
Integrating autovacuum into the server allows it to be
automatically started and stopped in sync with the database
server, and allows autovacuum to be configured from
postgresql.conf
.
SELECT ... FOR SHARE
(Alvaro)
While PostgreSQL's MVCC locking
allows SELECT
to never be blocked by writers and
therefore does not need shared row locks for typical operations,
shared locks are useful for applications that require shared row
locking. In particular this reduces the locking requirements
imposed by referential integrity checks.
This extension of the dependency mechanism prevents roles from being dropped while there are still database objects they own. Formerly it was possible to accidentally “orphan” objects by deleting their owner. While this could be recovered from, it was messy and unpleasant.
The new constraint_exclusion
configuration
parameter avoids lookups on child tables where constraints indicate
that no matching rows exist in the child table.
This allows for a basic type of table partitioning. If child tables
store separate key ranges and this is enforced using appropriate
CHECK
constraints, the optimizer will skip child
table accesses when the constraint guarantees no matching rows
exist in the child table.
A dump/restore using pg_dump is required for those wishing to migrate data from any previous release.
The 8.0 release announced that the to_char()
function
for intervals would be removed in 8.1. However, since no better API
has been suggested, to_char(interval)
has been enhanced in
8.1 and will remain in the server.
Observe the following incompatibilities:
add_missing_from
is now false by default (Neil)
By default, we now generate an error if a table is used in a query
without a FROM
reference. The old behavior is still
available, but the parameter must be set to 'true' to obtain it.
It might be necessary to set add_missing_from
to true
in order to load an existing dump file, if the dump contains any
views or rules created using the implicit-FROM
syntax.
This should be a one-time annoyance, because
PostgreSQL 8.1 will convert
such views and rules to standard explicit-FROM
syntax.
Subsequent dumps will therefore not have the problem.
Cause input of a zero-length string (''
) for
float4
/float8
/oid
to throw an error, rather than treating it as a zero (Neil)
This change is consistent with the current handling of zero-length strings for integers. The schedule for this change was announced in 8.0.
default_with_oids
is now false by default (Neil)
With this option set to false, user-created tables no longer
have an OID column unless WITH OIDS
is specified in
CREATE TABLE
. Though OIDs have existed in all
releases of PostgreSQL, their use is limited
because they are only four bytes long and the counter is shared
across all installed databases. The preferred way of uniquely
identifying rows is via sequences and the SERIAL
type,
which have been supported since PostgreSQL 6.4.
Add E''
syntax so eventually ordinary strings can
treat backslashes literally (Bruce)
Currently PostgreSQL processes a
backslash in a string literal as introducing a special escape sequence,
e.g. \n
or \010
.
While this allows easy entry of special values, it is
nonstandard and makes porting of applications from other
databases more difficult. For this reason, the
PostgreSQL project is planning to
remove the special meaning of backslashes in strings. For
backward compatibility and for users who want special backslash
processing, a new string syntax has been created. This new string
syntax is formed by writing an E
immediately preceding the
single quote that starts the string, e.g. E'hi\n'
. While
this release does not change the handling of backslashes in strings, it
does add new configuration parameters to help users migrate applications
for future releases:
standard_conforming_strings
— does this release
treat backslashes literally in ordinary strings?
escape_string_warning
— warn about backslashes in
ordinary (non-E) strings
The standard_conforming_strings
value is read-only.
Applications can retrieve the value to know how backslashes are
processed. (Presence of the parameter can also be taken as an
indication that E''
string syntax is supported.)
In a future release, standard_conforming_strings
will be true, meaning backslashes will be treated literally in
non-E strings. To prepare for this change, use E''
strings in places that need special backslash processing, and
turn on escape_string_warning
to find additional
strings that need to be converted to use E''
.
Also, use two single-quotes (''
) to embed a literal
single-quote in a string, rather than the
PostgreSQL-supported syntax of
backslash single-quote (\'
). The former is
standards-conforming and does not require the use of the
E''
string syntax. You can also use the
$$
string syntax, which does not treat backslashes
specially.
Make REINDEX DATABASE
reindex all indexes in the
database (Tom)
Formerly, REINDEX DATABASE
reindexed only
system tables. This new behavior seems more intuitive. A new
command REINDEX SYSTEM
provides the old functionality
of reindexing just the system tables.
Read-only large object descriptors now obey MVCC snapshot semantics
When a large object is opened with INV_READ
(and not
INV_WRITE
), the data read from the descriptor will now
reflect a “snapshot” of the large object's state at the
time of the transaction snapshot in use by the query that called
lo_open()
. To obtain the old behavior of always
returning the latest committed data, include INV_WRITE
in the mode flags for lo_open()
.
Add proper dependencies for arguments of sequence functions (Tom)
In previous releases, sequence names passed to nextval()
,
currval()
, and setval()
were stored as
simple text strings, meaning that renaming or dropping a
sequence used in a DEFAULT
clause made the clause
invalid. This release stores all newly-created sequence function
arguments as internal OIDs, allowing them to track sequence
renaming, and adding dependency information that prevents
improper sequence removal. It also makes such DEFAULT
clauses immune to schema renaming and search path changes.
Some applications might rely on the old behavior of
run-time lookup for sequence names. This can still be done by
explicitly casting the argument to text
, for example
nextval('myseq'::text)
.
Pre-8.1 database dumps loaded into 8.1 will use the old text-based
representation and therefore will not have the features of
OID-stored arguments. However, it is possible to update a
database containing text-based DEFAULT
clauses.
First, save this query into a file, such as fixseq.sql
:
SELECT 'ALTER TABLE ' || pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) || ' ALTER COLUMN ' || pg_catalog.quote_ident(a.attname) || ' SET DEFAULT ' || regexp_replace(d.adsrc, $$val\(\(('[^']*')::text\)::regclass$$, $$val(\1$$, 'g') || ';' FROM pg_namespace n, pg_class c, pg_attribute a, pg_attrdef d WHERE n.oid = c.relnamespace AND c.oid = a.attrelid AND a.attrelid = d.adrelid AND a.attnum = d.adnum AND d.adsrc ~ $$val\(\('[^']*'::text\)::regclass$$;
Next, run the query against a database to find what
adjustments are required, like this for database db1
:
psql -t -f fixseq.sql db1
This will show the ALTER TABLE
commands needed to
convert the database to the newer OID-based representation.
If the commands look reasonable, run this to update the database:
psql -t -f fixseq.sql db1 | psql -e db1
This process must be repeated in each database to be updated.
In psql, treat unquoted
\{digit}+
sequences as octal (Bruce)
In previous releases, \{digit}+
sequences were
treated as decimal, and only \0{digit}+
were treated
as octal. This change was made for consistency.
Remove grammar productions for prefix and postfix %
and ^
operators
(Tom)
These have never been documented and complicated the use of the
modulus operator (%
) with negative numbers.
Make &<
and &>
for polygons
consistent with the box "over" operators (Tom)
CREATE LANGUAGE
can ignore the provided arguments
in favor of information from pg_pltemplate
(Tom)
A new system catalog pg_pltemplate
has been defined
to carry information about the preferred definitions of procedural
languages (such as whether they have validator functions). When
an entry exists in this catalog for the language being created,
CREATE LANGUAGE
will ignore all its parameters except the
language name and instead use the catalog information. This measure
was taken because of increasing problems with obsolete language
definitions being loaded by old dump files. As of 8.1,
pg_dump will dump procedural language definitions as
just CREATE LANGUAGE
, relying
on a template entry to exist at load time. We expect this will be a
more future-proof representation.
name
Make pg_cancel_backend(int)
return a
boolean
rather than an integer
(Neil)
Some users are having problems loading UTF-8 data into 8.1.X.
This is because previous versions allowed invalid UTF-8 byte
sequences to be entered into the database, and this release
properly accepts only valid UTF-8 sequences. One way to correct a
dumpfile is to run the command iconv -c -f UTF-8 -t
UTF-8 -o cleanfile.sql dumpfile.sql
. The -c
option
removes invalid character sequences. A diff of the two files will
show the sequences that are invalid. iconv
reads the
entire input file into memory so it might be necessary to use
split to break up the dump into multiple smaller
files for processing.
Below you will find a detailed account of the additional changes between PostgreSQL 8.1 and the previous major release.
Improve GiST and R-tree index performance (Neil)
Improve the optimizer, including auto-resizing of hash joins (Tom)
Overhaul internal API in several areas
Change WAL record CRCs from 64-bit to 32-bit (Tom)
We determined that the extra cost of computing 64-bit CRCs was significant, and the gain in reliability too marginal to justify it.
Prevent writing large empty gaps in WAL pages (Tom)
Improve spinlock behavior on SMP machines, particularly Opterons (Tom)
Allow nonconsecutive index columns to be used in a multicolumn index (Tom)
For example, this allows an index on columns a,b,c to be used in
a query with WHERE a = 4 and c = 10
.
Skip WAL logging for CREATE TABLE AS
/
SELECT INTO
(Simon)
Since a crash during CREATE TABLE AS
would cause the
table to be dropped during recovery, there is no reason to WAL
log as the table is loaded. (Logging still happens if WAL
archiving is enabled, however.)
Allow concurrent GiST index access (Teodor, Oleg)
Add configuration parameter full_page_writes
to
control writing full pages to WAL (Bruce)
To prevent partial disk writes from corrupting the database, PostgreSQL writes a complete copy of each database disk page to WAL the first time it is modified after a checkpoint. This option turns off that functionality for more speed. This is safe to use with battery-backed disk caches where partial page writes cannot happen.
Use O_DIRECT
if available when using
O_SYNC
for wal_sync_method
(Itagaki Takahiro)
O_DIRECT
causes disk writes to bypass the kernel
cache, and for WAL writes, this improves performance.
Improve COPY FROM
performance (Alon Goldshuv)
This was accomplished by reading COPY
input in
larger chunks, rather than character by character.
Improve the performance of COUNT()
,
SUM
, AVG()
,
STDDEV()
, and
VARIANCE()
(Neil, Tom)
Prevent problems due to transaction ID (XID) wraparound (Tom)
The server will now warn when the transaction counter approaches the wraparound point. If the counter becomes too close to wraparound, the server will stop accepting queries. This ensures that data is not lost before needed vacuuming is performed.
Fix problems with object IDs (OIDs) conflicting with existing system objects after the OID counter has wrapped around (Tom)
Add warning about the need to increase
max_fsm_relations
and max_fsm_pages
during VACUUM
(Ron Mayer)
Add temp_buffers
configuration parameter to allow
users to determine the size of the local buffer area for
temporary table access (Tom)
Add session start time and client IP address to
pg_stat_activity
(Magnus)
Adjust pg_stat
views for bitmap scans (Tom)
The meanings of some of the fields have changed slightly.
Enhance pg_locks
view (Tom)
Log queries for client-side PREPARE
and
EXECUTE
(Simon)
Allow Kerberos name and user name case sensitivity to be
specified in postgresql.conf
(Magnus)
Add configuration parameter krb_server_hostname
so
that the server host name can be specified as part of service
principal (Todd Kover)
If not set, any service principal matching an entry in the keytab can be used. This is new Kerberos matching behavior in this release.
Add log_line_prefix
options for millisecond
timestamps (%m
) and remote host (%h
) (Ed
L.)
Add WAL logging for GiST indexes (Teodor, Oleg)
GiST indexes are now safe for crash and point-in-time recovery.
Remove old *.backup
files when we do
pg_stop_backup()
(Bruce)
This prevents a large number of *.backup
files from
existing in pg_xlog/
.
Add configuration parameters to control TCP/IP keep-alive times for idle, interval, and count (Oliver Jowett)
These values can be changed to allow more rapid detection of lost client connections.
Add per-user and per-database connection limits (Petr Jelinek)
Using ALTER USER
and ALTER DATABASE
,
limits can now be enforced on the maximum number of sessions that
can concurrently connect as a specific user or to a specific database.
Setting the limit to zero disables user or database connections.
Allow more than two gigabytes of shared memory and per-backend work memory on 64-bit machines (Koichi Suzuki)
New system catalog pg_pltemplate
allows overriding
obsolete procedural-language definitions in dump files (Tom)
Add temporary views (Koju Iijima, Neil)
Fix HAVING
without any aggregate functions or
GROUP BY
so that the query returns a single group (Tom)
Previously, such a case would treat the HAVING
clause the same as a WHERE
clause. This was not per spec.
Add USING
clause to allow additional tables to be
specified to DELETE
(Euler Taveira de Oliveira, Neil)
In prior releases, there was no clear method for specifying
additional tables to be used for joins in a DELETE
statement. UPDATE
already has a FROM
clause for this purpose.
Add support for \x
hex escapes in backend and ecpg
strings (Bruce)
This is just like the standard C \x
escape syntax.
Octal escapes were already supported.
Add BETWEEN SYMMETRIC
query syntax (Pavel Stehule)
This feature allows BETWEEN
comparisons without
requiring the first value to be less than the second. For
example, 2 BETWEEN [ASYMMETRIC] 3 AND 1
returns
false, while 2 BETWEEN SYMMETRIC 3 AND 1
returns
true. BETWEEN ASYMMETRIC
was already supported.
Add NOWAIT
option to SELECT ... FOR
UPDATE/SHARE
(Hans-Juergen Schoenig)
While the statement_timeout
configuration
parameter allows a query taking more than a certain amount of
time to be canceled, the NOWAIT
option allows a
query to be canceled as soon as a SELECT ... FOR
UPDATE/SHARE
command cannot immediately acquire a row lock.
Track dependencies of shared objects (Alvaro)
PostgreSQL allows global tables (users, databases, tablespaces) to reference information in multiple databases. This addition adds dependency information for global tables, so, for example, user ownership can be tracked across databases, so a user who owns something in any database can no longer be removed. Dependency tracking already existed for database-local objects.
Allow limited ALTER OWNER
commands to be performed
by the object owner (Stephen Frost)
Prior releases allowed only superusers to change object owners. Now, ownership can be transferred if the user executing the command owns the object and would be able to create it as the new owner (that is, the user is a member of the new owning role and that role has the CREATE permission that would be needed to create the object afresh).
Add ALTER
object SET SCHEMA
capability
for some object types (tables, functions, types) (Bernd Helmle)
This allows objects to be moved to different schemas.
Add ALTER TABLE ENABLE/DISABLE TRIGGER
to
disable triggers (Satoshi Nagayasu)
Allow TRUNCATE
to truncate multiple tables in a
single command (Alvaro)
Because of referential integrity checks, it is not allowed to
truncate a table that is part of a referential integrity
constraint. Using this new functionality, TRUNCATE
can be used to truncate such tables, if both tables involved in
a referential integrity constraint are truncated in a single
TRUNCATE
command.
Properly process carriage returns and line feeds in
COPY CSV
mode (Andrew)
In release 8.0, carriage returns and line feeds in CSV
COPY TO
were processed in an inconsistent manner. (This was
documented on the TODO list.)
Add COPY WITH CSV HEADER
to allow a header line as
the first line in COPY
(Andrew)
This allows handling of the common CSV
usage of
placing the column names on the first line of the data file. For
COPY TO
, the first line contains the column names,
and for COPY FROM
, the first line is ignored.
On Windows, display better sub-second precision in
EXPLAIN ANALYZE
(Magnus)
Add trigger duration display to EXPLAIN ANALYZE
(Tom)
Prior releases included trigger execution time as part of the total execution time, but did not show it separately. It is now possible to see how much time is spent in each trigger.
Add support for \x
hex escapes in COPY
(Sergey Ten)
Previous releases only supported octal escapes.
Make SHOW ALL
include variable descriptions
(Matthias Schmidt)
SHOW
varname still only displays the variable's
value and does not include the description.
Make initdb create a new standard
database called postgres
, and convert utilities to
use postgres
rather than template1
for
standard lookups (Dave)
In prior releases, template1
was used both as a
default connection for utilities like
createuser, and as a template for
new databases. This caused CREATE DATABASE
to
sometimes fail, because a new database cannot be created if
anyone else is in the template database. With this change, the
default connection database is now postgres
,
meaning it is much less likely someone will be using
template1
during CREATE DATABASE
.
Create new reindexdb command-line
utility by moving /contrib/reindexdb
into the
server (Euler Taveira de Oliveira)
Add MAX()
and MIN()
aggregates for
array types (Koju Iijima)
Fix to_date()
and to_timestamp()
to
behave reasonably when CC
and YY
fields
are both used (Karel Zak)
If the format specification contains CC
and a year
specification is YYY
or longer, ignore the
CC
. If the year specification is YY
or
shorter, interpret CC
as the previous century.
Add md5(bytea)
(Abhijit Menon-Sen)
md5(text)
already existed.
Add support for numeric ^ numeric
based on
power(numeric, numeric)
The function already existed, but there was no operator assigned to it.
Fix NUMERIC
modulus by properly truncating the quotient
during computation (Bruce)
In previous releases, modulus for large values sometimes returned negative results due to rounding of the quotient.
Add a function lastval()
(Dennis Björklund)
lastval()
is a simplified version of
currval()
. It automatically determines the proper
sequence name based on the most recent nextval()
or
setval()
call performed by the current session.
Add to_timestamp(DOUBLE PRECISION) (Michael Glaesemann)
Converts Unix seconds since 1970 to a TIMESTAMP WITH
TIMEZONE
.
Add pg_postmaster_start_time()
function (Euler
Taveira de Oliveira, Matthias Schmidt)
Allow the full use of time zone names in AT TIME
ZONE
, not just the short list previously available (Magnus)
Previously, only a predefined list of time zone names were
supported by AT TIME ZONE
. Now any supported time
zone name can be used, e.g.:
SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London';
In the above query, the time zone used is adjusted based on the daylight saving time rules that were in effect on the supplied date.
Add GREATEST()
and LEAST()
variadic
functions (Pavel Stehule)
These functions take a variable number of arguments and return the greatest or least value among the arguments.
Add pg_column_size()
(Mark Kirkwood)
This returns storage size of a column, which might be compressed.
Add regexp_replace()
(Atsushi Ogawa)
This allows regular expression replacement, like sed. An optional flag argument allows selection of global (replace all) and case-insensitive modes.
Fix interval division and multiplication (Bruce)
Previous versions sometimes returned unjustified results, like
'4 months'::interval / 5
returning '1 mon
-6 days'
.
Fix roundoff behavior in timestamp, time, and interval output (Tom)
This fixes some cases in which the seconds field would be shown as
60
instead of incrementing the higher-order fields.
Add a separate day field to type interval
so a one day
interval can be distinguished from a 24 hour interval (Michael
Glaesemann)
Days that contain a daylight saving time adjustment are not 24
hours long, but typically 23 or 25 hours. This change creates a
conceptual distinction between intervals of “so many days”
and intervals of “so many hours”. Adding
1 day
to a timestamp now gives the same local time on
the next day even if a daylight saving time adjustment occurs
between, whereas adding 24 hours
will give a different
local time when this happens. For example, under US DST rules:
'2005-04-03 00:00:00-05' + '1 day' = '2005-04-04 00:00:00-04' '2005-04-03 00:00:00-05' + '24 hours' = '2005-04-04 01:00:00-04'
Add justify_days()
and justify_hours()
(Michael Glaesemann)
These functions, respectively, adjust days to an appropriate number of full months and days, and adjust hours to an appropriate number of full days and hours.
Move /contrib/dbsize
into the backend, and rename
some of the functions (Dave Page, Andreas Pflug)
pg_tablespace_size()
pg_database_size()
pg_relation_size()
pg_total_relation_size()
pg_size_pretty()
pg_total_relation_size()
includes indexes and TOAST
tables.
Add functions for read-only file access to the cluster directory (Dave Page, Andreas Pflug)
pg_stat_file()
pg_read_file()
pg_ls_dir()
Add pg_reload_conf()
to force reloading of the
configuration files (Dave Page, Andreas Pflug)
Add pg_rotate_logfile()
to force rotation of the
server log file (Dave Page, Andreas Pflug)
Change pg_stat_*
views to include TOAST tables (Tom)
Rename some encodings to be more consistent and to follow international standards (Bruce)
UNICODE
is now UTF8
ALT
is now WIN866
WIN
is now WIN1251
TCVN
is now WIN1258
The original names still work.
Add support for WIN1252
encoding (Roland Volkmann)
Add support for four-byte UTF8
characters (John
Hansen)
Previously only one, two, and three-byte UTF8
characters
were supported. This is particularly important for support for
some Chinese character sets.
Allow direct conversion between EUC_JP
and
SJIS
to improve performance (Atsushi Ogawa)
Allow the UTF8 encoding to work on Windows (Magnus)
This is done by mapping UTF8 to the Windows-native UTF16 implementation.
Fix ALTER LANGUAGE RENAME
(Sergey Yatskevich)
Allow function characteristics, like strictness and volatility,
to be modified via ALTER FUNCTION
(Neil)
Increase the maximum number of function arguments to 100 (Tom)
Allow SQL and PL/pgSQL functions to use OUT
and
INOUT
parameters (Tom)
OUT
is an alternate way for a function to return
values. Instead of using RETURN
, values can be
returned by assigning to parameters declared as OUT
or
INOUT
. This is notationally simpler in some cases,
particularly so when multiple values need to be returned.
While returning multiple values from a function
was possible in previous releases, this greatly simplifies the
process. (The feature will be extended to other server-side
languages in future releases.)
Move language handler functions into the pg_catalog
schema
This makes it easier to drop the public schema if desired.
Add SPI_getnspname()
to SPI (Neil)
Overhaul the memory management of PL/pgSQL functions (Neil)
The parsetree of each function is now stored in a separate memory context. This allows this memory to be easily reclaimed when it is no longer needed.
Check function syntax at CREATE FUNCTION
time,
rather than at runtime (Neil)
Previously, most syntax errors were reported only when the function was executed.
Allow OPEN
to open non-SELECT
queries
like EXPLAIN
and SHOW
(Tom)
No longer require functions to issue a RETURN
statement (Tom)
This is a byproduct of the newly added OUT
and
INOUT
functionality. RETURN
can
be omitted when it is not needed to provide the function's
return value.
Add support for an optional INTO
clause to
PL/pgSQL's EXECUTE
statement (Pavel Stehule, Neil)
Make CREATE TABLE AS
set ROW_COUNT
(Tom)
Define SQLSTATE
and SQLERRM
to return
the SQLSTATE
and error message of the current
exception (Pavel Stehule, Neil)
These variables are only defined inside exception blocks.
Allow the parameters to the RAISE
statement to be
expressions (Pavel Stehule, Neil)
Add a loop CONTINUE
statement (Pavel Stehule, Neil)
Allow block and loop labels (Pavel Stehule)
Allow large result sets to be returned efficiently (Abhijit Menon-Sen)
This allows functions to use return_next()
to avoid
building the entire result set in memory.
Allow one-row-at-a-time retrieval of query results (Abhijit Menon-Sen)
This allows functions to use spi_query()
and
spi_fetchrow()
to avoid accumulating the entire
result set in memory.
Force PL/Perl to handle strings as UTF8
if the
server encoding is UTF8
(David Kamholz)
Add a validator function for PL/Perl (Andrew)
This allows syntax errors to be reported at definition time, rather than execution time.
Allow PL/Perl to return a Perl array when the function returns an array type (Andrew)
This basically maps PostgreSQL arrays to Perl arrays.
Allow Perl nonfatal warnings to generate NOTICE
messages (Andrew)
Allow Perl's strict
mode to be enabled (Andrew)
Add \set ON_ERROR_ROLLBACK
to allow statements in
a transaction to error without affecting the rest of the
transaction (Greg Sabino Mullane)
This is basically implemented by wrapping every statement in a sub-transaction.
Add support for \x
hex strings in
psql variables (Bruce)
Octal escapes were already supported.
Add support for troff -ms
output format (Roger
Leigh)
Allow the history file location to be controlled by
HISTFILE
(Andreas Seltenreich)
This allows configuration of per-database history storage.
Prevent \x
(expanded mode) from affecting
the output of \d tablename
(Neil)
Add -L
option to psql to
log sessions (Lorne Sunley)
This option was added because some operating systems do not have simple command-line activity logging functionality.
Make \d
show the tablespaces of indexes (Qingqing
Zhou)
Allow psql help (\h
) to
make a best guess on the proper help information (Greg Sabino
Mullane)
This allows the user to just add \h
to the front of
the syntax error query and get help on the supported syntax.
Previously any additional query text beyond the command name
had to be removed to use \h
.
Add \pset numericlocale
to allow numbers to be
output in a locale-aware format (Eugen Nedelcu)
For example, using C
locale 100000
would
be output as 100,000.0
while a European locale might
output this value as 100.000,0
.
Make startup banner show both server version number and psql's version number, when they are different (Bruce)
Also, a warning will be shown if the server and psql are from different major releases.
Add -n
/ --schema
switch to
pg_restore (Richard van den Berg)
This allows just the objects in a specified schema to be restored.
Allow pg_dump to dump large objects even in text mode (Tom)
With this change, large objects are now always dumped; the former
-b
switch is a no-op.
Allow pg_dump to dump a consistent snapshot of large objects (Tom)
Dump comments for large objects (Tom)
Add --encoding
to pg_dump
(Magnus Hagander)
This allows a database to be dumped in an encoding that is different from the server's encoding. This is valuable when transferring the dump to a machine with a different encoding.
Rely on pg_pltemplate
for procedural languages (Tom)
If the call handler for a procedural language is in the
pg_catalog
schema, pg_dump does not
dump the handler. Instead, it dumps the language using just
CREATE LANGUAGE
,
relying on the name
pg_pltemplate
catalog to provide
the language's creation parameters at load time.
Add a PGPASSFILE
environment variable to specify the
password file's filename (Andrew)
Add lo_create()
, that is similar to
lo_creat()
but allows the OID of the large object
to be specified (Tom)
Make libpq consistently return an error
to the client application on malloc()
failure (Neil)
Fix pgxs to support building against a relocated installation
Add spinlock support for the Itanium processor using Intel compiler (Vikram Kalsi)
Add Kerberos 5 support for Windows (Magnus)
Add Chinese FAQ (laser@pgsqldb.com)
Rename Rendezvous to Bonjour to match OS/X feature renaming (Bruce)
Add support for fsync_writethrough
on
macOS (Chris Campbell)
Streamline the passing of information within the server, the optimizer, and the lock system (Tom)
Allow pg_config to be compiled using MSVC (Andrew)
This is required to build DBD::Pg using MSVC.
Remove support for Kerberos V4 (Magnus)
Kerberos 4 had security vulnerabilities and is no longer maintained.
Code cleanups (Coverity static analysis performed by EnterpriseDB)
Modify postgresql.conf
to use documentation defaults
on
/off
rather than
true
/false
(Bruce)
Enhance pg_config to be able to report more build-time values (Tom)
Allow libpq to be built thread-safe on Windows (Dave Page)
Allow IPv6 connections to be used on Windows (Andrew)
Add Server Administration documentation about I/O subsystem reliability (Bruce)
Move private declarations from gist.h
to
gist_private.h
(Neil)
In previous releases, gist.h
contained both the
public GiST API (intended for use by authors of GiST index
implementations) as well as some private declarations used by
the implementation of GiST itself. The latter have been moved
to a separate file, gist_private.h
. Most GiST
index implementations should be unaffected.
Overhaul GiST memory management (Neil)
GiST methods are now always invoked in a short-lived memory
context. Therefore, memory allocated via palloc()
will be reclaimed automatically, so GiST index implementations
do not need to manually release allocated memory via
pfree()
.
Add /contrib/pg_buffercache
contrib module (Mark
Kirkwood)
This displays the contents of the buffer cache, for debugging and performance tuning purposes.
Remove /contrib/array
because it is obsolete (Tom)
Clean up the /contrib/lo
module (Tom)
Move /contrib/findoidjoins
to
/src/tools
(Tom)
Remove the <<
, >>
,
&<
, and &>
operators from
/contrib/cube
These operators were not useful.
Improve /contrib/btree_gist
(Janko Richter)
Improve /contrib/pgbench
(Tomoaki Sato, Tatsuo)
There is now a facility for testing with SQL command scripts given by the user, instead of only a hard-wired command sequence.
Improve /contrib/pgcrypto
(Marko Kreen)
Implementation of OpenPGP symmetric-key and public-key encryption
Both RSA and Elgamal public-key algorithms are supported.
Stand alone build: include SHA256/384/512 hashes, Fortuna PRNG
OpenSSL build: support 3DES, use internal AES with OpenSSL < 0.9.7
Take build parameters (OpenSSL, zlib) from configure
result
There is no need to edit the Makefile
anymore.
Remove support for libmhash
and libmcrypt