POSTIN

/bin/sh

/usr/sbin/update-alternatives --install /usr/sbin/zabbix_server \
    zabbix-server /usr/sbin/zabbix_server_pgsql 10 \
        --slave /usr/lib/systemd/system/zabbix-server.service zabbix-server-systemd \
            /usr/lib/systemd/system/zabbix-server-pgsql.service

POSTUN

/bin/sh

if [ $1 -eq 0 ] ; then
    /usr/sbin/update-alternatives --remove zabbix-server /usr/sbin/zabbix_server_pgsql
fi