[OSM-dev] New osm2pgsql long-term release

[Paul Norman]

A new long-term version of osm2pgsql has been released, 0.88.0. This
includes the work done in the 0.87.x development series and the porting 
to C++.

Like all versions, 0.88.0 can be obtained from 
https://github.com/openstreetmap/osm2pgsql

Potentially breaking changes

- A database reload is recommended. If not, the schema migrations in
https://github.com/openstreetmap/osm2pgsql/blob/master/docs/migrations.md
   are required.

- Osm2pgsql is now C++ and requires the Boost libraries. Build scripts and
   package dependencies may need adjustment

Major new features

- A new backend has been added, the “multi” backend. This allows multiple
   tables which can each contain different types of features. More
   documentation is available at 
https://github.com/openstreetmap/osm2pgsql/blob/master/docs/multi.md.

   One potential use for this feature is matching an existing schema for
   data, to allow OSM data to be a drop-in replacement.

- In-memory pending tracking instead of in-database, with significant
   performance gains.

- Rendering tables are ordered by GeoHash when created, resulting in
   significant performance improvements.

- z_logic has been improved, taking into account more recent work across
   multiple styles. https://github.com/openstreetmap/osm2pgsql/pull/374
   has more information.

Other changes

- The node storage has been improved, and out of order nodes and nodes
   at 0,0 should now always be handled correctly

- A new test suite with unit tests

- Many bug-fixes and cleanups

Known issues

- Append mode is not supported with non-slim. This is suported in
   0.89.0-dev, but is frequently a user error. Typically, when a user
   does this they should instead merge input files with osmosis/osmconvert
   and use --create

What's next?

osm2pgsql is switching to libosmium for parsing and will require a C++11
compiler. These changes are already in 0.89.0-dev. C++11 is enabling new
cleanups. Beyond this, it depends on contributor time and interest and if
anyone decides to pay for development.

User diary version: http://www.openstreetmap.org/user/pnorman/diary/35414