Difficult migration from Postgres 8.1 (postgis 1.5) to Postgres 9.4 (postgis 2.1) I am in charge of a system developed 8 years ago. When I make a dump of the postgres 8.1 database, all the postgis 1.5 functions are included. I have successfully migrated it to a postgres 9.1, because it still supports postgis 1.5, but as soon as I try to migrate to 9.4 I encounter many problems because of all the old spatial functions that are defined during the restore process. There are also all sorts of constraints defined using the old postgis 1.5 functions.

Is there an effective way of updating all these references from postgis 1.5 to postgis 2? Do I need to manually edit the backup files? (I have about 300 tables).

Thanks in advance :-)
Follow the hard upgrade procedure which uses postgis_restore.pl to help translate the differences between the versions.