pg_dbms_stats 1.3.9 and earlier has a bug that can crash a server. It may free memory blocks for statistics in use by planner being triggered by simultaneous ALTERing of tables related to a query currently planning. For example creating a child table of a table involved in the query can cause the problem. Crash caused by this issue is seldom seen on PostgreSQL that is built with --enable-cassert and hardly seen without the option.
PostgreSQL 9.2 support has been removed in this release because of its EOL.