# Upgrading PostgreSQL version on FreeBSD

For minimal downtime during migration, we will use `pg_upgrade` tool, which needs both old and new PostgreSQL binaries available. To do so, we will use FreeBSD's ports system, without `make clean` at first to keep compiled binaries.
## A note about locales

You might encounter weird locale issue while ensuing `initdb` command, like this:

```bash
FATAL:  could not load locale "sr_YU.ISO8859-5"
```

This seems to be caused by a [remaining deprecated locale](https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=274718#c12). You can delete it by using the following command, depending on if you're running PostgreSQL in a jail (I didn't find a cleaner way, sorry):

```bash
sudo rm -rf /usr/share/locale/sr_YU.ISO8859-5
sudo rm -rf /basejail/usr/share/locale/sr_YU.ISO8859-5
```

## Compile old and new version from ports

Replace `PSQLOLDVERSION` with major version of your existing PostgreSQL installation, and `PSQLNEWVERSION` with the new major version.

```bash
PSQLOLDVERSION=13
PSQLNEWVERSION=15

cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-server/ && make
cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-client/ && make deinstall
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-server/ && make
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-contrib/ && make

# if you disabled locale detection in initdb, you might want to save patched initdb binary:
cp -vrp /var/ports/basejail/usr/ports/databases/postgresql-server${PSQLNEWVERSION}/work/stage/usr/local/bin/initdb /usr/local/bin/initdb-nolocale

cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-server/ && make deinstall
cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-contrib/ && make deinstall
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-server/ && make install
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-contrib/ && make install

service postgresql stop 
```
## Migrate data

I run PostgreSQL inside a FreeBSD jail, so base path is `/var/ports/basejail/`. Adjust path if you run it outside a jail.

```bash
sudo -u postgres -i

# locale and encoding may vary
initdb -D /home/postgres/data${PSQLNEWVERSION} --locale=C --encoding=UTF8

# check upgrade
pg_upgrade -b /var/ports/basejail/usr/ports/databases/postgresql${PSQLOLDVERSION}-server/work/stage/usr/local/bin -B /usr/local/bin -d /home/postgres/data${PSQLOLDVERSION} -D /home/postgres/data${PSQLNEWVERSION} -c
# do upgrade
pg_upgrade -b /var/ports/basejail/usr/ports/databases/postgresql${PSQLOLDVERSION}-server/work/stage/usr/local/bin -B /usr/local/bin -d /home/postgres/data${PSQLOLDVERSION} -D /home/postgres/data${PSQLNEWVERSION}
```

## Migrate configuration files

```bash
cp data${PSQLOLDVERSION}/postgresql.conf data${PSQLNEWVERSION}/postgresql.conf
cp data${PSQLOLDVERSION}/pg_hba.conf data${PSQLNEWVERSION}/pg_hba.conf
```

## Go back to root user and finish migration

```bash
exit
service postgresql start
# I'm using pgbouncer on port 5432, so I chose 6432 for "native" port
psql -p 6432 < update_extensions.sql
/usr/local/bin/vacuumdb --port 6432 --all --analyze-in-stages

./delete_old_cluster.sh
```

## Clean ports (optional)

```bash
cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-server/ && make clean
cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-client/ && make clean
cd /usr/ports/databases/postgresql${PSQLOLDVERSION}-contrib/ && make clean

cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-server/ && make clean
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-client/ && make clean
cd /usr/ports/databases/postgresql${PSQLNEWVERSION}-contrib/ && make clean
```