lib/sql_io.py: put_table(): documented that PostgreSQL 9.1+ now provides a way to implement insert/on duplicate select just once for each table (instead of dynamically for each insert) using the new INSTEAD OF triggers (http://www.postgresql.org/docs/9.1/static/plpgsql-trigger.html). INSTEAD OF triggers were not used when put_table() was developed, because it was necessary to support PostgreSQL 9.0, which was installed on the Mac and not easily upgradeable. it was eventually upgraded to add PostGIS, which required a complete reinstall of the DB from the staging tables, with the associated staging table reload bugs, as well as complete removal of the old Postgres version.
lib/sql_io.py: put_table(): documented that PostgreSQL 9.1+ now provides a way to implement insert/on duplicate select just once for each table (instead of dynamically for each insert) using the new INSTEAD OF triggers (http://www.postgresql.org/docs/9.1/static/plpgsql-trigger.html). INSTEAD OF triggers were not used when put_table() was developed, because it was necessary to support PostgreSQL 9.0, which was installed on the Mac and not easily upgradeable. it was eventually upgraded to add PostGIS, which required a complete reinstall of the DB from the staging tables, with the associated staging table reload bugs, as well as complete removal of the old Postgres version.