Improvements:

• New --checkunique option added to the checkdb command to work together with --amcheck and verify unique constraints during logical verification of indexes when the amcheck extension is installed in the database and its version supports the verification of unique constraints.

Major bugfixes:

• catchup: fix data corruption in delta and ptrack modes, before that, the source database could be damaged when using these modes (#459).

Bugfixes:

• archive-push: --wal-file-path option now works in accord with documentation. Now you can call arсhive-push not only from the postgres working directory, but also from an arbitrary directory (#437, #330, #265, fixed in 2.5.3)
• catchup: fix that catchup incorrectly checks the timeline history in some cases (#463).

Packaging:

• fix rhel-8 repo (#455).
• drop support of debian-8, ubuntu-14.04 and ubuntu-16.04 packages

Issues:

• https://github.com/postgrespro/pg_probackup/milestone/34?closed=1
• https://github.com/postgrespro/pg_probackup/milestone/31?closed=1

Bugfixes:

• Unlogged relations are correctly excluded from backup now. Reported by @Zergvl
• ENOSPC is now detected correctly when writing data. Reported by @slothfk
• wal directory in instance catalog can now be symlinked. Reported by @triwada
• CVE-2018-1058 is fixed

Improvements:

• New command catchup is implemented. With it you can now fast-forward fallen-behind standby using changed data from master. Developed by @kulaginm
• Important information and messages are now colored
• Added PG14 support
• Added RH8 support
• Added Debian11 support
• Ptrack 1.x support is dropped.
• Package support for 9.5 is dropped, but old packages are still available in repo
• Package support for Centos 6 and RHEL 6 is dropped, but old packages are still available in repo

Issues:
https://github.com/postgrespro/pg_probackup/milestone/19

Bugfixes:

• Fix integer overflow of variable storing the offset of page header map. Reported by @sms1222
• Fix broken backward compatibility for backups of versions 2.0.22, 2.0.24 and 2.0.25. Affected version: 2.4.10. Reported by @shab2
• Do not delete invalid full backups within retention redundancy range. Reported by @triwada
• Correctly handle backups with empty backup.control. Reported by Mikhail Grigorev
• Empty WAL .history files are now handled correctly. Reported by Denis Podolsky
• Do no report meaningless timestamp when deleting backup without valid "recovery-time" attribute. Reported by Roman Zharkov
• Detect failure in WAL streaming correctly and report it as soon as possible. Reported by Yuri Kurenkov (#346)
• Do sync and rename when writing to configuration file pg_probackup.conf
• More robust parsing of tablespace_map content. Reported by Vasiliy Puchkov

Improvements:

• At the start of incremental backup the timeline switch of PostgreSQL instance is now detected automatically via replication protocol using TIMELINE_HISTORY command. Requested by Alex Ignatov
• Flags --no-validate and --no-sync are now can be used when running merge or retention merge operations.

Issues:
https://github.com/postgrespro/pg_probackup/milestone/28?closed=1

Bugfixes:

• Due to false-positive crc match it was possible to erroneously reuse pg_filenode.map file during incremental restore, which could break pg_catalog relations relying on pg_filenode.map for filenode mapping if they were subject to VACUUM FULL or REINDEX operations before backup. This is fixed now.
• A race condition between reader and writer in acquiring the backup exclusive lock is removed.
• File descriptor leak in the backup shared lock is fixed.

Improvements:

• The remote agent API is now stable across the same minor version starting with 2.4.9, which makes pg_probackup installations more robust towards version drift. Requested by Alex Ignatov.
• It is now possible to restore and validate a backup from a read-only filesystem. Requested by Mikhail Kulagin.
• Backup shared locks are now released at the process exit.

Bugfixes:

• SIGPIPE signal is now handled. Reported by Yuri Kurenkov.
• Error conditions encountered by remote agent are now reported correctly. Reported by Yuri Kurenkov.
• It is now possible to start taking more than one backup a second. Previously an attempt to do so resulted in an error. Reported by Daria Lepikhova.
• Waiting for Start LSN now happens after the parent backup is chosen, which allows us to error out earlier if there is no suitable parent.

Improvements:

• --force flag for restore in incremental mode now allows us to overwrite the contents of the directory specified by PGDATA in case of system ID mismatch. Previously this resulted in an error.

Bugfixes:

• Fix segfault if environment variable TZ is set. Reported by @deric
• Parsing of long config values (such as 1KB long value for --note option) now works correctly. Reported by @popov83

Bugfixes:

• WAL history files are now backed up correctly when taking autonomous backup. Reported by @Azmodey
• Streamed WAL segments are now fsynced to disk at the end of backup

Bugfixes:

• For PG >= 12 use postgresql.auto.conf for recovery settings instead of separate included file. Reported by Mikhail Kulagin
• Fix time skew for DST timezones, metadata timestamps are now stored in UTC. Reported by @juergennagel
• Log files are now rotated correctly. Reported by @alexandermalykhin

Improvements:

• Disable "in-place" merge only if storage format changed. Requested by @alexandermalykhin
• Non-exclusive backup locks are implemented, concurrent validate and restore are now possible.
• Streamed WAL segments are now added to backup filelist on the fly. Requested by @triwada
• Streamed WAL segments are now fsynced to disk at the end of backup. Reported by Alex Ignatov

Bugfixes:

• fixed memory leak in pagemap extraction routine. Reported by @beremour
• fixed integer overflow in checkdb. Reported by Nikolay Popov
• now temp files in pgsql_tmp directory are excluded during backup. Reported by @beremour
• retention merge after remote backup now works correctly. Reported by @Guzya
• for ptrack 1.x version backups in ptrack mode can be taken in series. Reported by Roman Zharkov
• during instance validation multi-timeline backup chain can be validated correctly. Reported by @lalbrecht

Improvements:

• SUSE 15.2 packages are available in repository
• PostgreSQL 13 is supported and packages are available in repository
• possibility of WAL archive corruption due to double switchover reported to PostgreSQL community. Reported by @lalbrecht. Thread: https://www.postgresql-archive.org/history-file-on-replica-and-double-switchover-td6151536.html