velocity is a schema-less, multi-keyed dictionary of fixed temporal size.

Conceptually, the entries consist of a list of tagged tuples. The entries are indexed by some number of the tagged tuples. There is no primary key and no schema. Each insert can be of unique form. It has bag semantics, i.e. there can be several entries with the same keys.

Each insert will remove all entries that are "too old", i.e. older than the timeout. The timeout is settable through the cfg function, e.g. velocity:cfg(timeout,2) sets the timeout to 2 hours.

velocity:insert takes two arguments, both of which are lists of tagged tuples. The elements of the first list are indexed, the elements of the second list are not. E.g. calling

velocity:insert([{a,"A"},{b,"B"}],[{c,"C"},{d,"D"}]).

will allow you to find this entry by calling velocity:find(a,"A") or velocity:find(b,"B").

Likewise, entries can be deleted by calling velocity:delete on any of the indexed tags, like; velocity:delete(b,"B").