<application>pg_upgrade</application> (formerly called <application>pg_migrator</application>) allows data

stored in <productname>PostgreSQL</productname> data files to be upgraded to a later <productname>PostgreSQL</productname>

major version without the data dump/restore typically required for

major version upgrades, e.g., from9.5.8 to9.6.4 or from10.7 to11.2.

It is not required for minor version upgrades, e.g., from9.6.2 to9.6.3

or from10.1 to10.2.

major version upgrades, e.g., from12.14 to13.10 or from14.9 to15.5.

It is not required for minor version upgrades, e.g., from12.7 to12.8

or from14.1 to14.5.

</para>

<para>

Make sure both database servers are stopped using, on Unix, e.g.:

<programlisting>

pg_ctl -D /opt/PostgreSQL/9.6 stop

pg_ctl -D /opt/PostgreSQL/12 stop

pg_ctl -D /opt/PostgreSQL/&majorversion; stop

</programlisting>

or on Windows, using the proper service names:

<programlisting>

NET STOP postgresql-9.6

NET STOP postgresql-12

NET STOP postgresql-&majorversion;

</programlisting>

</para>

<programlisting>

pg_upgrade.exe

--old-datadir "C:/Program Files/PostgreSQL/9.6/data"

--old-datadir "C:/Program Files/PostgreSQL/12/data"

--new-datadir "C:/Program Files/PostgreSQL/&majorversion;/data"

--old-bindir "C:/Program Files/PostgreSQL/9.6/bin"

--old-bindir "C:/Program Files/PostgreSQL/12/bin"

--new-bindir "C:/Program Files/PostgreSQL/&majorversion;/bin"

</programlisting>

remote directory, e.g.,

<programlisting>

rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/9.5 \

/opt/PostgreSQL/9.6 standby.example.com:/opt/PostgreSQL

rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/12 \

/opt/PostgreSQL/&majorversion; standby.example.com:/opt/PostgreSQL

</programlisting>

You can verify what the command will do using

<application>rsync</application> command for each tablespace directory, e.g.:

<programlisting>

rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_9.5_201510051 \

/vol1/pg_tblsp/PG_9.6_201608131 standby.example.com:/vol1/pg_tblsp

rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_12_201909212 \

/vol1/pg_tblsp/PG_&majorversion;_202307071 standby.example.com:/vol1/pg_tblsp

</programlisting>

If you have relocated <filename>pg_wal</filename> outside the data