Fedora 34 Change: PostgreSQL 13 (Self-Contained Change)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/PostgreSQL_13


== Summary ==
Update of PostgreSQL (`postgresql` and `libpq` components) in Fedora
from version 12 to version 13 in the non-modular (main) builds.

Also, there will be a design change in postgresql modular packaging
regarding the external libpq library ensuring future build time
compatibility. More information in the Detailed Description section.

== Owner ==
* Name: [[User:panovotn| Patrik Novotny]]
* Email: panovotn(a)redhat.com


== Detailed Description ==
Update of PostgreSQL (`postgresql` and `libpq` components) in Fedora
from version 12 to version 13 in the non-modular (main) builds.

This also involves updating and rebuilding the PostgreSQL plugins that
depend on postgresql server.

There will also be a change to the packaging of postgresql modules, as
with those, the external libpq library can be potentially problematic
upon upstream releases.

As postgresql packages are built against the separated libpq package,
an incompatibility between major versions can occur with new minor
upstream releases. For example, when building postgresql version 12.4
against libpq version 13.1.

To keep the benefits of having separately maintained libpq library,
libpq stays as a separate package.

However, to solve the potential issues with the postgresql builds, we
will bundle libpq with a downstream changed SONAME within each
postgresql release. The postgresql will be built against this libpq.

This bundled libpq will always be the same version as the
corresponding postgresql as they will share the same codebase. As the
libpq SONAME will be changed downstream to a non-standard SONAME, and
separate libpq package with standard SONAME will be provided, this
change won't affect the user experience for those components.

=== Plan ===

* Prepare Libpq 13, PostgreSQL 13 (both rawhide and module) and
PostgreSQL 12 module
* Rebuild dependencies in Copr
** By 2021-01-15

* Debug and fix compatibility issues found in dependencies (reasonable
amount of non-critical in FTBFS state might be tolerable)
** By 2021-01-22

* Prepare builds in a side-tag
* Merge side-tag into Rawhide
** By 2021-01-29

== Benefit to Fedora ==

Latest stable software is used by Fedora users.

== Scope ==
* Proposal owners:
<!-- What work do the feature owners have to accomplish to complete
the feature in time for release?  Is it a large change affecting many
parts of the distribution or is it a very isolated change? What are
those changes?-->
**Prepare PostgreSQL 13 as a module for Rawhide and at least one
stable Fedora release (including the design change and symbol
versioning fix)
**Prepare PostgreSQL 12 as a module for Rawhide
**Check software that requires or depends on `postgresql-server` or
`libpq` packages for incompatibilities
**Build PostgreSQL 13 (postgresql and libpq) to Rawhide in a side-tag
(https://fedoraproject.org/wiki/Package_update_HOWTO#Creating_a_side-tag)
**Rebuild depended packages against PostgreSQL 13 in the side-tag (see
Dependencies)
**Merge the side-tag to Rawhide
**Gather user input on the changes between PostgreSQL 12 and PostgreSQL 13

* Other developers: N/A (not a System Wide Change)
* Policies and guidelines: N/A (not a System Wide Change)
* Trademark approval: N/A (not needed for this Change)

== Upgrade/compatibility impact ==
The PostgreSQL client library (libpq component) is compatible, but
there is an issue with symbol versioning (originally reported
https://bugzilla.redhat.com/show_bug.cgi?id=1893324 was reverted, but
there is a plan to fix this properly together with this PostgreSQL
update tracked in
https://bugzilla.redhat.com/show_bug.cgi?id=1908268). So, there
shouldn't be any issues with API compatibility, but rebuild of the
depended components is necessary.

Server plugins might require a newer version update, because they
sometimes have explicit server requirements. PostgreSQL maintainer
will help fixing/rebuilding any issues in the plugins.

== How To Test ==

Usual testing as when upgrading between major PostgreSQL versions,
running `postgresql-setup --upgrade` is necessary between major
versions.

Test that all other software runs well with PostgreSQL 13.

== User Experience ==

The users will have to upgrade their databases the same way as between
major PostgreSQL versions, aka `postgresql-setup --upgrade` after
installing PostgreSQL 13 server packages.

If users want to stick with PostgreSQL 12 for a little longer, there
will be PostgreSQL 12 module

== Dependencies ==

There are some packages (mostly server plugins), that build on top of
PostgreSQL. Since the separation of PostgreSQL client library (libpq
component), only packages that build server plugins should use
postgresql package in BuildRequires, others should use libpq. In both
the cases, rebuild should be done to make sure all potential binary
incompatibilities are handled.

* Critical dependecies - components with higher importance, will be
prioritised during the rebase
** apr-util
** bacula
** bind
** cyrus-imapd
** cyrus-sasl
** dovecot
** freeradius
** gdal
** libecpg
** nagios-plugins
** opendbx
** perl-DBD-Pg
** php
** pgaudit
** postfix
** qt
** qt3
** qt5-qtbase
** redland
** rsyslog
** rubygem-pg
** postgres-decoderbufs

The rest of the dependencies is not considered critical. Though, those
will need to be rebuild as well.

* libpq
** EMBOSS
** Io-language
** PDAL
** PyGreSQL
** asterisk
** biboumi
** clisp
** collectd
** dpsearch
** exim
** flow-tools
** freight-tools
** gambas3
** gammu
** gawk-pgsql
** gearmand
** gnatcoll-db
** gnokii
** grass
** hydra
** jabberd
** kdb
** kea
** libdbi-drivers
** libgda
** libnss-pgsql
** libpqxx
** libpreludedb
** libzdb
** lua-dbi
** lua-sql
** mapnik
** mapserver
** medusa
** minetestmapper
** ocaml-postgresql
** opensips
** openvas-manager
** osm2pgsql
** pdns
** perl-pgsql_perl5
** pg_top
** pgadmin3
** pgcenter
** pgmodeler
** php-pecl-pq
** player
** postgis
** postgresql
** postgresql-pgpool-II
** proftpd
** pspp
** pure-ftpd
** rdkit
** rhdb-utils
** root
** saga
** soci
** spatialite-gui
** sphinx
** sysbench
** tcl-pgtcl
** unicornscan
** virtualpg
** vtk
** zabbix

* postgresql-server
** gambas3
** kdb
** kea
** libpqxx
** openvas-manager
** orafce
** pg-semver
** pgRouting
** pgadmin3
** pgsphere
** postgis
** postgresql-ip4r
** postgresql-pgpool-II
** qt3
** rdkit
** rhdb-utils
** timescaledb

== Contingency Plan ==

Revert changes in the non-modular packages and provide PostgreSQL 13
as a module stream only.

Soft contingency plan deadline: Before Mass Rebuild (scheduled on Wed
2021-01-20)

Hard contingency plan deadline: Before Branch Fedora 34 from Rawhide
(scheduled on Tue 2021-02-09)

== Documentation ==

Upgrade startegy: https://www.postgresql.org/docs/13/upgrading.html

== Release Notes ==

Release notes for PostgreSQL 13 release:
https://www.postgresql.org/docs/13/index.html

Overall overview of the changes and improvements:
https://www.postgresql.org/docs/13/release-13.html


-- 
Ben Cotton
He / Him / His
Senior Program Manager, Fedora & CentOS Stream
Red Hat
TZ=America/Indiana/Indianapolis