Debian version numbers, used to version debian binary and source packages, have a defined format, including specifications for how versions should be compared in order to sort them. this package implements a "debversion" type to represent debian version numbers within the postgresql database. this also includes operators for version comparison and index operator classes for creating indexes on the debversion type.

version comparison uses the algorithm used by the debian package manager, dpkg, using the implementation from libapt-pkg. this means that columns in tables using the debversion type may be sorted and compared correctly using the same logic as "dpkg --compare-versions". it is also possible to create indexes on these columns.

postgresql-debversion implements the following features:

* the "debversion" type (internally derived from the "text" type)
* a full set of operators for version comparison (< <= = <> >= >)
including commutator and negator optimisation hints
* operator classes for btree and hash indexes
* the aggregate functions min() and max()