There are three commands that can be used to query the database:

• db_query: Obtain one or more objects that satisfy a query
• db_count: Count objects that satisfy a query
• db_ids: Obtain ids of objects that satisfy a query

Queries are given as perl hashes. In its most basic form a query has the form property1_value1_property2_value2} for example dim_3_n_vertices_7} Note that the database is pretty strict with types, so strings always need to be quoted, while integers should not be. The following would fail: dim_3} You can query elements in an array with their index, e.g. f_vector.1_12} gives polytopes with 5 edges (the entry at position one of the f-vector.