Allow table statistics for indexes to be approximate; speeds up Oracle
Allow table statistics for indexes to be approximate; speeds up Oracle

Fixes #47.

kares/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter