E.4. Release 13

E.4.1. 개요
E.4.2. 13 버전으로 마이그레이션 하기
E.4.3. 바뀐점
E.4.4. Acknowledgments

출시일: 2020-09-24

E.4.1. 개요

PostgreSQL 13 주요 새 기능과 개선사항:

  • B-tree 인덱스 중복 항목 없애서 크기를 줄이고 속도를 높혔다.

  • 집계 작업이나 파티션 테이블 작업 쿼리 성능을 높혔다.

  • 확장 통계 정보를 사용할 때 쿼리 실행 계획이 보다 똑똑해졌다.

  • 인덱스 청소 작업을 병렬로 할 수 있다.

  • 증분 정렬 Incremental sorting

PostgreSQL 13의 위에서 소개한 것들과 기타 새 기능들의 보다 자세한 사항은 아래에서 다룬다.

E.4.2. 13 버전으로 마이그레이션 하기

이전 버전에서 사용했던 자료를 마이그레이션 하려면, pg_dumpall 명령을 이용한 덤프/복원 작업을 하거나, pg_upgrade 명령을 이용하거나, 논리 복제 기법을 쓴다. 기존 자료를 새 버전에서 사용하려는 마이그레이션 작업에 대한 일반적인 내용은 18.6절에서 자세히 다룬다.

13 버전은 하위 버전 호환성에 영향을 미치는 여러 변경 사항을 포한한다. 다음은 하위 버전과 호환되지 않는 것들이다:

  • SIMILAR TO ... ESCAPE NULL 구문은 이제 NULL을 반환한다. (Tom Lane)

    이 새 정책은 SQL 표준 규약을 따르기 위해서 적용되었다. 이전 버전에서는 ESCAPE NULL을 사용하면, 기본 이스케이프 문자열(백슬래쉬 문자)을 사용하는 것으로 간주하였다. 이 정책은 substring(text FROM pattern ESCAPE text) 구문에서도 적용된다. 예전부터 사용했던 함수를 바꾸지 않음으로 예전부터 사용했던 뷰의 하위 호환성은 유지했다.

  • json[b]_to_tsvector() 함수에서 사용하는 string 옵션의 철자를 엄격하게 확인한다. (Dominik Czarnota)

  • effective_io_concurrency 설정값이 기본값이 아닌 경우 그 영향도 계산 방식이 바뀌었다. (Thomas Munro)

    이전 버전에서는 동시 요청 수를 지정하기 전에, 이 설정값을 조정했다. 이제부터는 이 값은 그대로 사용된다. 이전버전에서 사용했던 값은 이 버전부터는 다음과 같이 계산해서 바꿔 사용하면 된다:

    SELECT round(sum(OLDVALUE / n::float)) AS newvalue FROM generate_series(1, OLDVALUE) s(n);
    
  • pg_stat_ssl 뷰와 pg_stat_gssapi 뷰에서 상관 없는 프로세스들은 이제 보이지 않는다. (Euler Taveira)

    pg_stat_activity와 조인할 경우, ssl, gssapi 연결과 상관 없는 프로세스들도 함께 보려면, left 조인을 해야한다.

  • 보다 나은 일관성을 위해 wait event 이름을 바꿨다. (Fujii Masao, Tom Lane)

  • ALTER FOREIGN TABLE ... RENAME COLUMN 명령 결과를 좀더 정확하게 바꿨다. (Fujii Masao)

    이전 버전에서는 ALTER TABLE을 반환했고, 이제부터 ALTER FOREIGN TABLE을 반환한다.

  • ALTER MATERIALIZED VIEW ... RENAME COLUMN 명령 결과를 좀더 정확하게 바꿨다. (Fujii Masao)

    이전 버전에서는 ALTER TABLE을 반환했고, 이제부터 ALTER MATERIALIZED VIEW를 반환한다.

  • wal_keep_segments 환경 설정 매개 변수가 wal_keep_size로 바뀜 (Fujii Masao)

    이 설정은 대기 서버를 위해 남겨 놓을 WAL 양을 지정한다. 이전 버전에서는 WAL 파일 수로 지정했으나, 이제는 총 메가 바이트 단위로 지정한다. 예전 wal_keep_segments 값은 다음과 같은 계산식으로 크기를 계산한다:

    wal_keep_size = wal_keep_segments * wal_segment_size (통상 16MB)
    

  • 8.0 이전 버전의 연산자 클래스 정의 문법을 더 이상 지원하지 않는다. (Daniel Gustafsson)

  • 7.3 이전 버전의 참조키 제약조건 정의 문법을 더 이상 지원하지 않는다. (Daniel Gustafsson)

  • 7.3 이전 버전의 "opaque" 의사 자료형을 더 이상 지원하지 않는다. (Daniel Gustafsson)

  • 패키지화 되지 않은 확장 모듈(9.1 이전 버전)의 업그레이드를 지원하지 않는다. (Tom Lane)

    CREATE EXTENSION 명령에서 FROM 옵션을 지원하지 않는다. 패키지화 되지 않은 확장 모듈은 13버전으로 바꾸기 전에 먼저 패키지로 묶는 작업을 해야한다.

  • 지역시간대 데이터베이스에서 posixrules 파일들을 지원하지 않는다. (Tom Lane)

    IANA(Internet Assigned Numbers Authority 인터넷 할당 번호 관리기관)의 지역시간대 그룹은 이 기능을 없앴다. 따라서 향후 몇 년 사이에, 시스템의 지역시간대 데이터베이스에서도 없어질 것이다. 지역시간대 자료가 업데이트 됨에 따라 예상치 않게 시간 처리가 될 소지가 있어, 13 버전에서 이 기능을 없앴다. 이 조치는 POSIX 스타일 지역시간대 명세에만 국한된다. 사용자 정의 posixrules 파일을 만들어 잘못 계산 될 수 있는 일광 시간 절약 변환 규칙을 명시적으로 지정해 문제를 풀어가는 방법이었다. 이제는 이 방법을 사용할 수 없다. 추천하는 지역시간대는 지리적인 지역시간대 이름을 사용하는 것이다.

  • ltree 확장 모듈을 사용할 때, 중괄호 앞 별표를 사용하는 lquery인 경우 이제 바르게 처리한다. 예, *{2}.*{3}*{5} 로 처리한다. (Nikita Glukhov)

  • pageinspect 확장 모듈의 bt_metap() 함수 반환값에 사용하는 자료형 중 자료형 오버플로우가 일어날 가능성이 있는 자료형들은 보다 큰 자료형으로 바꿨다. (Peter Geoghegan)

E.4.3. 바뀐점

Below you will find a detailed account of the changes between PostgreSQL 13 and the previous major release.

E.4.3.1. Server

E.4.3.1.1. Partitioning
  • 보다 다양한 경우에도, 파티션 테이블 가지치기 pruning를 할 수 있다. (Yuzuko Hosoya, Amit Langote, Álvaro Herrera)

  • 보다 다양한 경우에도, partitionwise 조인을 할 수 있다. (Ashutosh Bapat, Etsuro Fujita, Amit Langote, Tom Lane)

    예를 들어 파티션 경계가 정확하게 딱 맞지 않아도 파티션 테이블 사이 파티션와이즈 조인이 가능하다.

  • Support row-level BEFORE triggers on partitioned tables (Álvaro Herrera)

    However, such a trigger is not allowed to change which partition is the destination.

  • Allow partitioned tables to be logically replicated via publications (Amit Langote)

    Previously, partitions had to be replicated individually. Now a partitioned table can be published explicitly, causing all its partitions to be published automatically. Addition/removal of a partition causes it to be likewise added to or removed from the publication. The CREATE PUBLICATION option publish_via_partition_root controls whether changes to partitions are published as their own changes or their parent's.

  • Allow logical replication into partitioned tables on subscribers (Amit Langote)

    Previously, subscribers could only receive rows into non-partitioned tables.

  • Allow whole-row variables (that is, table.*) to be used in partitioning expressions (Amit Langote)

E.4.3.1.2. Indexes
  • More efficiently store duplicates in B-tree indexes (Anastasia Lubennikova, Peter Geoghegan)

    This allows efficient B-tree indexing of low-cardinality columns by storing duplicate keys only once. Users upgrading with pg_upgrade will need to use REINDEX to make an existing index use this feature.

  • Allow GiST and SP-GiST indexes on box columns to support ORDER BY box <-> point queries (Nikita Glukhov)

  • Allow GIN indexes to more efficiently handle ! (NOT) clauses in tsquery searches (Nikita Glukhov, Alexander Korotkov, Tom Lane, Julien Rouhaud)

  • Allow index operator classes to take parameters (Nikita Glukhov)

  • Allow CREATE INDEX to specify the GiST signature length and maximum number of integer ranges (Nikita Glukhov)

    Indexes created on four and eight-byte integer array, tsvector, pg_trgm, ltree, and hstore columns can now control these GiST index parameters, rather than using the defaults.

  • Prevent indexes that use non-default collations from being added as a table's unique or primary key constraint (Tom Lane)

    The index's collation must match that of the underlying column, but ALTER TABLE previously failed to check this.

E.4.3.1.3. Optimizer
  • Improve the optimizer's selectivity estimation for containment/match operators (Tom Lane)

  • Allow setting the statistics target for extended statistics (Tomas Vondra)

    This is controlled with the new command option ALTER STATISTICS ... SET STATISTICS. Previously this was computed based on more general statistics target settings.

  • Allow use of multiple extended statistics objects in a single query (Tomas Vondra)

  • Allow use of extended statistics objects for OR clauses and IN/ANY constant lists (Pierre Ducroquet, Tomas Vondra)

  • Allow functions in FROM clauses to be pulled up (inlined) if they evaluate to constants (Alexander Kuzmenkov, Aleksandr Parfenov)

E.4.3.1.4. General Performance
  • Implement incremental sorting (James Coleman, Alexander Korotkov, Tomas Vondra)

    If an intermediate query result is known to be sorted by one or more leading keys of a required sort ordering, the additional sorting can be done considering only the remaining keys, if the rows are sorted in batches that have equal leading keys.

    If necessary, this can be controlled using enable_incremental_sort.

  • Improve the performance of sorting inet values (Brandur Leach)

  • 큰 집계 결과 집합을 해시 집계로 처리할 때 디스크를 사용할 수 있다. (Jeff Davis)

    이전 버전에서는 해시 집계인 경우 work_mem 설정값보다 그 집계 결과가 더 클 것으로 예상 되는 경우, 해시 집계 계획을 짜지 않았다. 이제 이런 경우에도 해시 집계 계획이 선택될 수 있다. 해시 자료 결과가 work_mem 값의 hash_mem_multiplier 배가 넘으면 디스크를 사용한다.

    일단 해시 집계 계획이 선택되면 무조건 그 필요한 메모리만큼 확보하고 그곳에 해시 자료를 담는 예전 방식보다 낫다. — 실행 계획기가 잘못 예측하면, 꽤 많은 메모리를 사용하게 된다. 필요하다면, hash_mem_multiplier 값을 늘려 해시 집계에 사용할 메모리를 크게 확보하는 방법으로 이전 버전의 처리 방식처럼 처리할 수 있다.

  • Allow inserts, not only updates and deletes, to trigger vacuuming activity in autovacuum (Laurenz Albe, Darafei Praliaskouski)

    Previously, insert-only activity would trigger auto-analyze but not auto-vacuum, on the grounds that there could not be any dead tuples to remove. However, a vacuum scan has other useful side-effects such as setting page-all-visible bits, which improves the efficiency of index-only scans. Also, allowing an insert-only table to receive periodic vacuuming helps to spread out the work of freezing old tuples, so that there is not suddenly a large amount of freezing work to do when the entire table reaches the anti-wraparound threshold all at once.

    If necessary, this behavior can be adjusted with the new parameters autovacuum_vacuum_insert_threshold and autovacuum_vacuum_insert_scale_factor, or the equivalent table storage options.

  • Add maintenance_io_concurrency parameter to control I/O concurrency for maintenance operations (Thomas Munro)

  • wal_level 설정값이 minimal일 때, 릴레이션 새로 만들기, 다시 쓰기 관련 WAL를 건너뛸 수 있다. (Kyotaro Horiguchi)

    기록할 자료량이 wal_skip_threshold 설정값보다 큰 경우 WAL 기록을 하지 않고, 직접 데이터 파일 fsync 작업을 한다. 이전 버전에서는 COPY 작업일 때만 이렇게 했는데, 이 기능이 복구 작업 때, 자료를 잃을 가능성이 있었다.

  • Improve performance when replaying DROP DATABASE commands when many tablespaces are in use (Fujii Masao)

  • Improve performance for truncation of very large relations (Kirk Jamison)

  • Improve retrieval of the leading bytes of TOAST'ed values (Binguo Bao, Andrey Borodin)

    Previously, compressed out-of-line TOAST values were fully fetched even when it's known that only some leading bytes are needed. Now, only enough data to produce the result is fetched.

  • Improve performance of LISTEN/NOTIFY (Martijn van Oosterhout, Tom Lane)

  • Speed up conversions of integers to text (David Fetter)

  • Reduce memory usage for query strings and extension scripts that contain many SQL statements (Amit Langote)

E.4.3.1.5. Monitoring
  • Allow EXPLAIN, auto_explain, autovacuum, and pg_stat_statements to track WAL usage statistics (Kirill Bychik, Julien Rouhaud)

  • Allow a sample of SQL statements, rather than all statements, to be logged (Adrien Nayrat)

    A log_statement_sample_rate fraction of those statements taking more than log_min_duration_sample duration will be logged.

  • Add the backend type to csvlog and optionally log_line_prefix log output (Peter Eisentraut)

  • Improve control of prepared statement parameter logging (Alexey Bashtanov, Álvaro Herrera)

    The GUC setting log_parameter_max_length controls the maximum length of parameter values output during logging of non-error statements, while log_parameter_max_length_on_error does the same for logging of statements with errors. Previously, prepared statement parameters were never logged during errors.

  • Allow function call backtraces to be logged after errors (Peter Eisentraut, Álvaro Herrera)

    The new parameter backtrace_functions specifies which C functions should generate backtraces on error.

  • Make vacuum buffer counters 64-bits wide to avoid overflow (Álvaro Herrera)

E.4.3.1.6. System Views
E.4.3.1.7. Wait Events
  • Report a wait event while creating a DSM segment with posix_fallocate() (Thomas Munro)

  • Add wait event VacuumDelay to report on cost-based vacuum delay (Justin Pryzby)

  • Add wait events for WAL archive and recovery pause (Fujii Masao)

    The new events are BackupWaitWalArchive and RecoveryPause.

  • Add wait events RecoveryConflictSnapshot and RecoveryConflictTablespace to monitor recovery conflicts (Masahiko Sawada)

  • Improve performance of wait events on BSD-based systems (Thomas Munro)

E.4.3.1.8. Authentication
  • Allow only superusers to view the ssl_passphrase_command setting (Insung Moon)

    This was changed as a security precaution.

  • Change the server's default minimum TLS version for encrypted connections from 1.0 to 1.2 (Peter Eisentraut)

    This choice can be controlled by ssl_min_protocol_version.

E.4.3.1.9. Server Configuration
  • Tighten rules on which utility commands are allowed in read-only transaction mode (Robert Haas)

    This change also increases the number of utility commands that can run in parallel queries.

  • Allow allow_system_table_mods to be changed after server start (Peter Eisentraut)

  • Disallow non-superusers from modifying system tables when allow_system_table_mods is set (Peter Eisentraut)

    Previously, if allow_system_table_mods was set at server start, non-superusers could issue INSERT/UPDATE/DELETE commands on system tables.

  • Enable support for Unix-domain sockets on Windows (Peter Eisentraut)

E.4.3.2. Streaming Replication and Recovery

  • Allow streaming replication configuration settings to be changed by reload (Sergei Kornilov)

    Previously, a server restart was required to change primary_conninfo and primary_slot_name.

  • Allow WAL receivers to use a temporary replication slot when a permanent one is not specified (Peter Eisentraut, Sergei Kornilov)

    This behavior can be enabled using wal_receiver_create_temp_slot.

  • Allow WAL storage for replication slots to be limited by max_slot_wal_keep_size (Kyotaro Horiguchi)

    Replication slots that would require exceeding this value are marked invalid.

  • Allow standby promotion to cancel any requested pause (Fujii Masao)

    Previously, promotion could not happen while the standby was in paused state.

  • Generate an error if recovery does not reach the specified recovery target (Leif Gunnar Erlandsen, Peter Eisentraut)

    Previously, a standby would promote itself upon reaching the end of WAL, even if the target was not reached.

  • Allow control over how much memory is used by logical decoding before it is spilled to disk (Tomas Vondra, Dilip Kumar, Amit Kapila)

    This is controlled by logical_decoding_work_mem.

  • Allow recovery to continue even if invalid pages are referenced by WAL (Fujii Masao)

    This is enabled using ignore_invalid_pages.

E.4.3.3. Utility Commands

  • Allow VACUUM to process a table's indexes in parallel (Masahiko Sawada, Amit Kapila)

    The new PARALLEL option controls this.

  • Allow FETCH FIRST to use WITH TIES to return any additional rows that match the last result row (Surafel Temesgen)

  • Report planning-time buffer usage in EXPLAIN's BUFFER output (Julien Rouhaud)

  • Make CREATE TABLE LIKE propagate a CHECK constraint's NO INHERIT property to the created table (Ildar Musin, Chris Travers)

  • When using LOCK TABLE on a partitioned table, do not check permissions on the child tables (Amit Langote)

  • Allow OVERRIDING USER VALUE on inserts into identity columns (Dean Rasheed)

  • Add ALTER TABLE ... DROP EXPRESSION to allow removing the GENERATED property from a column (Peter Eisentraut)

  • Fix bugs in multi-step ALTER TABLE commands (Tom Lane)

    IF NOT EXISTS clauses now work as expected, in that derived actions (such as index creation) do not execute if the column already exists. Also, certain cases of combining related actions into one ALTER TABLE now work when they did not before.

  • Add ALTER VIEW syntax to rename view columns (Fujii Masao)

    Renaming view columns was already possible, but one had to write ALTER TABLE RENAME COLUMN, which is confusing.

  • Add ALTER TYPE options to modify a base type's TOAST properties and support functions (Tomas Vondra, Tom Lane)

  • Add CREATE DATABASE LOCALE option (Peter Eisentraut)

    This combines the existing options LC_COLLATE and LC_CTYPE into a single option.

  • Allow DROP DATABASE to disconnect sessions using the target database, allowing the drop to succeed (Pavel Stehule, Amit Kapila)

    This is enabled by the FORCE option.

  • Add structure member tg_updatedcols to allow C-language update triggers to know which column(s) were updated (Peter Eisentraut)

E.4.3.4. Data Types

  • Add polymorphic data types for use by functions requiring compatible arguments (Pavel Stehule)

    The new data types are anycompatible, anycompatiblearray, anycompatiblenonarray, and anycompatiblerange.

  • Add SQL data type xid8 to expose FullTransactionId (Thomas Munro)

    The existing xid data type is only four bytes so it does not provide the transaction epoch.

  • Add data type regcollation and associated functions, to represent OIDs of collation objects (Julien Rouhaud)

  • Use the glibc version in some cases as a collation version identifier (Thomas Munro)

    If the glibc version changes, a warning will be issued about possible corruption of collation-dependent indexes.

  • Add support for collation versions on Windows (Thomas Munro)

  • Allow ROW expressions to have their members extracted with suffix notation (Tom Lane)

    For example, (ROW(4, 5.0)).f1 now returns 4.

E.4.3.5. Functions

  • Add alternate version of jsonb_set() with improved NULL handling (Andrew Dunstan)

    The new function, jsonb_set_lax(), handles a NULL new value by either setting the specified key to a JSON null, deleting the key, raising an exception, or returning the jsonb value unmodified, as requested.

  • Add jsonpath .datetime() method (Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov)

    This function allows JSON values to be converted to timestamps, which can then be processed in jsonpath expressions. This change also adds jsonpath functions that support time-zone-aware output.

  • Add SQL functions NORMALIZE() to normalize Unicode strings, and IS NORMALIZED to check for normalization (Peter Eisentraut)

  • Add min() and max() aggregates for pg_lsn (Fabrízio de Royes Mello)

    These are particularly useful in monitoring queries.

  • Allow Unicode escapes, e.g., E'\unnnn' or U&'\nnnn', to specify any character available in the database encoding, even when the database encoding is not UTF-8 (Tom Lane)

  • Allow to_date() and to_timestamp() to recognize non-English month/day names (Juan José Santamaría Flecha, Tom Lane)

    The names recognized are the same as those output by to_char() with the same format patterns.

  • Add datetime format patterns FF1FF6 to specify input or output of 1 to 6 fractional-second digits (Alexander Korotkov, Nikita Glukhov, Teodor Sigaev, Oleg Bartunov)

    These patterns can be used by to_char(), to_timestamp(), and jsonpath's .datetime().

  • Add SSSSS datetime format pattern as an SQL-standard alias for SSSS (Nikita Glukhov, Alexander Korotkov)

  • Add function gen_random_uuid() to generate version-4 UUIDs (Peter Eisentraut)

    Previously UUID generation functions were only available in the external modules uuid-ossp and pgcrypto.

  • Add greatest-common-denominator (gcd) and least-common-multiple (lcm) functions (Vik Fearing)

  • Improve the performance and accuracy of the numeric type's square root (sqrt) and natural log (ln) functions (Dean Rasheed)

  • Add function min_scale() that returns the number of digits to the right of the decimal point that are required to represent a numeric value with full accuracy (Pavel Stehule)

  • Add function trim_scale() to reduce the scale of a numeric value by removing trailing zeros (Pavel Stehule)

  • Add commutators of distance operators (Nikita Glukhov)

    For example, previously only point <-> line was supported, now line <-> point works too.

  • Create xid8 versions of all transaction ID functions (Thomas Munro)

    The old xid-based functions still exist, for backward compatibility.

  • Allow get_bit() and set_bit() to set bits beyond the first 256MB of a bytea value (Movead Li)

  • Allow advisory-lock functions to be used in some parallel operations (Tom Lane)

  • Add the ability to remove an object's dependency on an extension (Álvaro Herrera)

    The object can be a function, materialized view, index, or trigger. The syntax is ALTER .. NO DEPENDS ON.

E.4.3.6. PL/pgSQL

  • Improve performance of simple PL/pgSQL expressions (Tom Lane, Amit Langote)

  • Improve performance of PL/pgSQL functions that use immutable expressions (Konstantin Knizhnik)

E.4.3.7. Client Interfaces

  • Allow libpq clients to require channel binding for encrypted connections (Jeff Davis)

    Using the libpq connection parameter channel_binding forces the other end of the TLS connection to prove it knows the user's password. This prevents man-in-the-middle attacks.

  • Add libpq connection parameters to control the minimum and maximum TLS version allowed for an encrypted connection (Daniel Gustafsson)

    The settings are ssl_min_protocol_version and ssl_max_protocol_version. By default, the minimum TLS version is 1.2 (this represents a behavioral change from previous releases).

  • Allow use of passwords to unlock client certificates (Craig Ringer, Andrew Dunstan)

    This is enabled by libpq's sslpassword connection parameter.

  • Allow libpq to use DER-encoded client certificates (Craig Ringer, Andrew Dunstan)

  • Fix ecpg's EXEC SQL elif directive to work correctly (Tom Lane)

    Previously it behaved the same as endif followed by ifdef, so that a successful previous branch of the same if construct did not prevent expansion of the elif branch or following branches.

E.4.3.8. Client Applications

E.4.3.8.1. psql
  • Add transaction status (%x) to psql's default prompts (Vik Fearing)

  • Allow the secondary psql prompt to be blank but the same width as the primary prompt (Thomas Munro)

    This is accomplished by setting PROMPT2 to %w.

  • Allow psql's \g and \gx commands to change \pset output options for the duration of that single command (Tom Lane)

    This feature allows syntax like \g (expand=on), which is equivalent to \gx.

  • Add psql commands to display operator classes and operator families (Sergey Cherkashin, Nikita Glukhov, Alexander Korotkov)

    The new commands are \dAc, \dAf, \dAo, and \dAp.

  • Show table persistence in psql's \dt+ and related commands (David Fetter)

    In verbose mode, the table/index/view shows if the object is permanent, temporary, or unlogged.

  • Improve output of psql's \d for TOAST tables (Justin Pryzby)

  • Fix redisplay after psql's \e command (Tom Lane)

    When exiting the editor, if the query doesn't end with a semicolon or \g, the query buffer contents will now be displayed.

  • Add \warn command to psql (David Fetter)

    This is like \echo except that the text is sent to stderr instead of stdout.

  • Add the PostgreSQL home page to command-line --help output (Peter Eisentraut)

E.4.3.8.2. pgbench
  • Allow pgbench to partition its accounts table (Fabien Coelho)

    This allows performance testing of partitioning.

  • Add pgbench command \aset, which behaves like \gset, but for multiple queries (Fabien Coelho)

  • Allow pgbench to generate its initial data server-side, rather than client-side (Fabien Coelho)

  • Allow pgbench to show script contents using option --show-script (Fabien Coelho)

E.4.3.9. Server Applications

  • Generate backup manifests for base backups, and verify them (Robert Haas)

    A new tool pg_verifybackup can verify backups.

  • Have pg_basebackup estimate the total backup size by default (Fujii Masao)

    This computation allows pg_stat_progress_basebackup to show progress. If that is not needed, it can be disabled by using the --no-estimate-size option. Previously, this computation happened only if the --progress option was used.

  • Add an option to pg_rewind to configure standbys (Paul Guo, Jimmy Yih, Ashwin Agrawal)

    This matches pg_basebackup's --write-recovery-conf option.

  • Allow pg_rewind to use the target cluster's restore_command to retrieve needed WAL (Alexey Kondratov)

    This is enabled using the -c/--restore-target-wal option.

  • Have pg_rewind automatically run crash recovery before rewinding (Paul Guo, Jimmy Yih, Ashwin Agrawal)

    This can be disabled by using --no-ensure-shutdown.

  • Increase the PREPARE TRANSACTION-related information reported by pg_waldump (Fujii Masao)

  • Add pg_waldump option --quiet to suppress non-error output (Andres Freund, Robert Haas)

  • Add pg_dump option --include-foreign-data to dump data from foreign servers (Luis Carril)

  • Allow vacuum commands run by vacuumdb to operate in parallel mode (Masahiko Sawada)

    This is enabled with the new --parallel option.

  • Allow reindexdb to operate in parallel (Julien Rouhaud)

    Parallel mode is enabled with the new --jobs option.

  • Allow dropdb to disconnect sessions using the target database, allowing the drop to succeed (Pavel Stehule)

    This is enabled with the -f option.

  • Remove --adduser and --no-adduser from createuser (Alexander Lakhin)

    The long-supported preferred options for this are called --superuser and --no-superuser.

  • Use the directory of the pg_upgrade program as the default --new-bindir setting when running pg_upgrade (Daniel Gustafsson)

E.4.3.10. Documentation

E.4.3.11. Source Code

  • Add support for building on Visual Studio 2019 (Haribabu Kommi)

  • Add build support for MSYS2 (Peter Eisentraut)

  • Add compare_exchange and fetch_add assembly language code for Power PC compilers (Noah Misch)

  • Update Snowball stemmer dictionaries used by full text search (Panagiotis Mavrogiorgos)

    This adds Greek stemming and improves Danish and French stemming.

  • Remove support for Windows 2000 (Michael Paquier)

  • Remove support for non-ELF BSD systems (Peter Eisentraut)

  • Remove support for Python versions 2.5.X and earlier (Peter Eisentraut)

  • Remove support for OpenSSL 0.9.8 and 1.0.0 (Michael Paquier)

  • Remove configure options --disable-float8-byval and --disable-float4-byval (Peter Eisentraut)

    These were needed for compatibility with some version-zero C functions, but those are no longer supported.

  • Pass the query string to planner hook functions (Pascal Legrand, Julien Rouhaud)

  • Add TRUNCATE command hook (Yuli Khodorkovskiy)

  • Add TLS init hook (Andrew Dunstan)

  • Allow building with no predefined Unix-domain socket directory (Peter Eisentraut)

  • Reduce the probability of SysV resource key collision on Unix platforms (Tom Lane)

  • Use operating system functions to reliably erase memory that contains sensitive information (Peter Eisentraut)

    For example, this is used for clearing passwords stored in memory.

  • Add headerscheck script to test C header-file compatibility (Tom Lane)

  • Implement internal lists as arrays, rather than a chain of cells (Tom Lane)

    This improves performance for queries that access many objects.

  • Change the API for TS_execute() (Tom Lane, Pavel Borisov)

    TS_execute callbacks must now provide ternary (yes/no/maybe) logic. Calculating NOT queries accurately is now the default.

E.4.3.12. Additional Modules

  • Allow extensions to be specified as trusted (Tom Lane)

    Such extensions can be installed in a database by users with database-level CREATE privileges, even if they are not superusers. This change also removes the pg_pltemplate system catalog.

  • Allow non-superusers to connect to postgres_fdw foreign servers without using a password (Craig Ringer)

    Specifically, allow a superuser to set password_required to false for a user mapping. Care must still be taken to prevent non-superusers from using superuser credentials to connect to the foreign server.

  • Allow postgres_fdw to use certificate authentication (Craig Ringer)

    Different users can use different certificates.

  • Allow sepgsql to control access to the TRUNCATE command (Yuli Khodorkovskiy)

  • Add extension bool_plperl which transforms SQL booleans to/from PL/Perl booleans (Ivan Panchenko)

  • Have pg_stat_statements treat SELECT ... FOR UPDATE commands as distinct from those without FOR UPDATE (Andrew Gierth, Vik Fearing)

  • Allow pg_stat_statements to optionally track the planning time of statements (Julien Rouhaud, Pascal Legrand, Thomas Munro, Fujii Masao)

    Previously only execution time was tracked.

  • Overhaul ltree's lquery syntax to treat NOT (!) more logically (Filip Rembialkowski, Tom Lane, Nikita Glukhov)

    Also allow non-* queries to use a numeric range ({}) of matches.

  • Add support for binary I/O of ltree, lquery, and ltxtquery types (Nino Floris)

  • Add an option to dict_int to ignore the sign of integers (Jeff Janes)

  • Add adminpack function pg_file_sync() to allow fsync'ing a file (Fujii Masao)

  • Add pageinspect functions to output t_infomask/t_infomask2 values in human-readable format (Craig Ringer, Sawada Masahiko, Michael Paquier)

  • pageinspect 확장모듈 출력에서 btree 인덱스 중복제거 작업상황에대한 컬럼이 추가되었다. (Peter Geoghegan)

E.4.4. Acknowledgments

The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.

Abhijit Menon-Sen
Adam Lee
Adam Scott
Adé Heyward
Adrien Nayrat
Ahsan Hadi
Alastair McKinley
Aleksandr Parfenov
Alex Aktsipetrov
Alex Macy
Alex Shulgin
Alexander Korotkov
Alexander Kukushkin
Alexander Kuzmenkov
Alexander Lakhin
Alexey Bashtanov
Alexey Kondratov
Álvaro Herrera
Amit Kapila
Amit Khandekar
Amit Langote
Amul Sul
Anastasia Lubennikova
Andreas Joseph Krogh
Andreas Karlsson
Andreas Kunert
Andreas Seltenreich
Andrei Zubkov
Andres Freund
Andrew Bille
Andrew Dunstan
Andrew Gierth
Andrey Borodin
Andrey Klychkov
Andrey Lepikhov
Anna Akenteva
Anna Endo
Anthony Nowocien
Anton Vlasov
Antonin Houska
Ants Aasma
Arne Roland
Arnold Müller
Arseny Sher
Arthur Nascimento
Arthur Zakirov
Ashutosh Bapat
Ashutosh Sharma
Ashwin Agrawal
Asif Rehman
Asim Praveen
Atsushi Torikoshi
Augustinas Jokubauskas
Austin Drenski
Basil Bourque
Beena Emerson
Ben Cornett
Benjie Gillam
Benoît Lobréau
Bernd Helmle
Bharath Rupireddy
Bhargav Kamineni
Binguo Bao
Brad DeJong
Brandur Leach
Brent Bates
Brian Williams
Bruce Momjian
Cameron Ezell
Cary Huang
Chapman Flack
Charles Offenbacher
Chen Huajun
Chenyang Lu
Chris Bandy
Chris Travers
Christoph Berg
Christophe Courtois
Corey Huinker
Craig Ringer
Cuiping Lin
Dagfinn Ilmari Mannsåker
Daniel Fiori
Daniel Gustafsson
Daniel Vérité
Daniel Westermann
Darafei Praliaskouski
Daryl Waycott
Dave Cramer
David Christensen
David Fetter
David G. Johnston
David Gilman
David Harper
David Rowley
David Steele
David Zhang
Davinder Singh
Dean Rasheed
Denis Stuchalin
Dent John
Didier Gautheron
Dilip Kumar
Dmitry Belyavsky
Dmitry Dolgov
Dmitry Ivanov
Dmitry Telpt
Dmitry Uspenskiy
Dominik Czarnota
Dongming Liu
Ed Morley
Edmund Horner
Emre Hasegeli
Eric Gillum
Erik Rijkers
Erwin Brandstetter
Ethan Waldo
Etsuro Fujita
Eugen Konkov
Euler Taveira
Fabien Coelho
Fabrízio de Royes Mello
Felix Lechner
Filip Janus
Filip Rembialkowski
Frank Gagnepain
Georgios Kokolatos
Gilles Darold
Greg Nancarrow
Grigory Smolkin
Guancheng Luo
Guillaume Lelarge
Hadi Moshayedi
Haiying Tang
Hamid Akhtar
Hans Buschmann
Hao Wu
Haribabu Kommi
Haruka Takatsuka
Heath Lord
Heikki Linnakangas
Himanshu Upadhyaya
Hironobu Suzuki
Hugh McMaster
Hugh Ranalli
Hugh Wang
Ian Barwick
Ibrar Ahmed
Ildar Musin
Insung Moon
Ireneusz Pluta
Isaac Morland
Ivan Kartyshov
Ivan Panchenko
Ivan Sergio Borgonovo
Jaime Casanova
James Coleman
James Gray
James Hunter
James Inform
James Lucas
Jan Mussler
Jaroslav Sivy
Jeevan Chalke
Jeevan Ladhe
Jeff Davis
Jeff Janes
Jehan-Guillaume de Rorthais
Jeremy Evans
Jeremy Schneider
Jeremy Smith
Jerry Sievers
Jesper Pedersen
Jesse Kinkead
Jesse Zhang
Jian Zhang
Jie Zhang
Jim Nasby
Jimmy Yih
Jobin Augustine
Joe Conway
John Hsu
John Naylor
Jon Jensen
Jonathan Katz
Jorge Gustavo Rocha
Josef Šimánek
Joseph Nahmias
Juan José Santamaría Flecha
Julian Backes
Julien Rouhaud
Jürgen Purtz
Justin King
Justin Pryzby
Karl O. Pinc
Keisuke Kuroda
Keith Fiske
Kelly Min
Ken Tanzer
Kirill Bychik
Kirk Jamison
Konstantin Knizhnik
Kuntal Ghosh
Kyle Kingsbury
Kyotaro Horiguchi
Lars Kanis
Laurenz Albe
Leif Gunnar Erlandsen
Li Japin
Liudmila Mantrova
Lucas Viecelli
Luis M. Carril
Lukáš Sobotka
Maciek Sakrejda
Magnus Hagander
Mahadevan Ramachandran
Mahendra Singh Thalor
Manuel Rigger
Marc Munro
Marcos David
Marina Polyakova
Mark Dilger
Mark Wong
Marko Tiikkaja
Markus Winand
Marti Raudsepp
Martijn van Oosterhout
Masahiko Sawada
Masahiro Ikeda
Masao Fujii
Mateusz Guzik
Matt Jibson
Matteo Beccati
Maxence Ahlouche
Melanie Plageman
Michael Banck
Michael Luo
Michael Meskes
Michael Paquier
Michail Nikolaev
Mike Palmiotto
Mithun Cy
Movead Li
Nathan Bossart
Nazli Ugur Koyluoglu
Neha Sharma
Nicola Contu
Nicolás Alvarez
Nikhil Sontakke
Nikita Glukhov
Nikolay Shaplov
Nino Floris
Noah Misch
Noriyoshi Shinoda
Oleg Bartunov
Oleg Samoilov
Oleksii Kliukin
Ondrej Jirman
Panagiotis Mavrogiorgos
Pascal Legrand
Patrick McHardy
Paul Guo
Paul Jungwirth
Paul Ramsey
Paul Sivash
Paul Spencer
Pavan Deolasee
Pavel Borisov
Pavel Luzanov
Pavel Stehule
Pavel Suderevsky
Peifeng Qiu
Pengzhou Tang
Peter Billen
Peter Eisentraut
Peter Geoghegan
Peter Smith
Petr Fedorov
Petr Jelínek
Phil Bayer
Philip Semanchuk
Philippe Beaudoin
Pierre Ducroquet
Pierre Giraud
Piotr Gabriel Kosinski
Piotr Wlodarczyk
Prabhat Sahu
Quan Zongliang
Quentin Rameau
Rafael Castro
Rafia Sabih
Raj Mohite
Rajkumar Raghuwanshi
Ramanarayana M
Ranier Vilela
Rares Salcudean
Raúl Marín Rodríguez
Raymond Martin
Reijo Suhonen
Richard Guo
Robert Ford
Robert Haas
Robert Kahlert
Robert Treat
Robin Abbi
Robins Tharakan
Roger Harkavy
Roman Peshkurov
Rui DeSousa
Rui Hai Jiang
Rushabh Lathia
Ryan Lambert
Ryohei Takahashi
Scott Ribe
Sean Farrell
Sehrope Sarkuni
Sergei Agalakov
Sergei Kornilov
Sergey Cherkashin
Shawn Debnath
Shawn Wang
Shay Rojansky
Shenhao Wang
Simon Riggs
Slawomir Chodnicki
Soumyadeep Chakraborty
Stéphane Lorek
Stephen Frost
Steve Rogerson
Steven Winfield
Surafel Temesgen
Suraj Kharage
Takanori Asaba
Takao Fujii
Takayuki Tsunakawa
Takuma Hoshiai
Tatsuhito Kasahara
Tatsuo Ishii
Tatsuro Yamada
Taylor Vesely
Teodor Sigaev
Tham Nguyen
Thibaut Madelaine
Thom Brown
Thomas Kellerer
Thomas Munro
Tiago Anastacio
Tim Clarke
Tim Möhlmann
Tom Ellis
Tom Gottfried
Tom Lane
Tomas Vondra
Tuomas Leikola
Tushar Ahuja
Victor Wagner
Victor Yegorov
Vignesh C
Vik Fearing
Vinay Banakar
Vladimir Leskov
Vladimir Sitnikov
Vyacheslav Makarov
Vyacheslav Shablistyy
Will Leinweber
William Crowell
Wyatt Alt
Yang Xiao
Yaroslav Schekin
Yi Huang
Yigong Hu
Yoann La Cancellera
Yoshikazu Imai
Yu Kimura
Yugo Nagata
Yuli Khodorkovskiy
Yusuke Egashira
Yuya Watari
Yuzuko Hosoya
ZhenHua Cai