Further pg_upgrade Enhancements and Logical Replication Applications in PostgreSQL 18

<nathan@postgresql.org> 2024-09-16 [6ab8f27bc] pg_upgrade: Parallelize retrieving extension updates. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [bbf83cab9] pg_upgrade: Parallelize data type checks. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [9db3018cf] pg_upgrade: Parallelize contrib/isn check. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [c34eabfbb] pg_upgrade: Parallelize postfix operator check. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [cf2f82a37] pg_upgrade: Parallelize incompatible polymorphics check. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [f93f5f7b9] pg_upgrade: Parallelize WITH OIDS check. Author: Nathan Bossart <nathan@postgresql.org> 2024-09-16 [c880cf258] pg_upgrade: Parallelize encoding conversion check. --> <listitem> <para> Allow pg_upgrade to process database checks in parallel (Nathan Bossart) <ulink url="&commit_baseurl;40e2e5e92">§</ulink> <ulink url="&commit_baseurl;6d3d2e8e5">§</ulink> <ulink url="&commit_baseurl;7baa36de5">§</ulink> <ulink url="&commit_baseurl;46cad8b31">§</ulink> <ulink url="&commit_baseurl;6ab8f27bc">§</ulink> <ulink url="&commit_baseurl;bbf83cab9">§</ulink> <ulink url="&commit_baseurl;9db3018cf">§</ulink> <ulink url="&commit_baseurl;c34eabfbb">§</ulink> <ulink url="&commit_baseurl;cf2f82a37">§</ulink> <ulink url="&commit_baseurl;f93f5f7b9">§</ulink> <ulink url="&commit_baseurl;c880cf258">§</ulink> </para> <para> This is controlled by the existing --jobs option. </para> </listitem>  <listitem> <para> Add pg_upgrade option --swap to swap directories rather than copy, clone, or link files (Nathan Bossart) <ulink url="&commit_baseurl;626d7236b">§</ulink> </para> <para> This mode is potentially the fastest. </para> </listitem>  <listitem> <para> Add pg_upgrade option --set-char-signedness to set the default char signedness of new cluster (Masahiko Sawada) <ulink url="&commit_baseurl;a8238f87f">§</ulink> <ulink url="&commit_baseurl;1aab68059">§</ulink> </para> <para> This is to handle cases where a pre-Postgres 18 cluster's default CPU signedness does not match the new cluster. </para> </listitem> </itemizedlist> </sect4> <sect4 id="release-18-logicalrep-app"> <title>Logical Replication Applications</title> <itemizedlist>  <listitem> <para> Add pg_createsubscriber option --all to create logical replicas for all databases (Shubham Khanna) <ulink url="&commit_baseurl;fb2ea12f4">§</ulink> </para> </listitem>  <listitem> <para> Add pg_createsubscriber option --remove to remove publications (Shubham Khanna) <ulink url="&commit_baseurl;e5aeed4b8">§</ulink> </para> </listitem>  <listitem> <para> Add pg_createsubscriber option --enable-two-phase to enable prepared transactions (Shubham Khanna) <ulink url="&commit_baseurl;e117cfb2f">§</ulink> </para> </listitem>  <listitem> <para> Add pg_recvlogical option --failover to specify failover slots (Hayato Kuroda) <ulink url="&commit_baseurl;cf2655a90">§</ulink> </para> </listitem> <!-- Author:

This section highlights additional improvements to pg_upgrade, including the --swap option for faster directory handling, and the --set-char-signedness option to manage default char signedness in new clusters. It also introduces new options for pg_createsubscriber, such as --all for creating logical replicas across all databases, --remove for removing publications, and --enable-two-phase for enabling prepared transactions. Additionally, pg_recvlogical gains a --failover option for specifying failover slots.