+
+ Special forms:
+ * a field starting with the ~ character means negation.
+ example : { '~peer_id' : None }
+ * a field starting with < [ ] or > means lower than or greater than
+ < > uses strict comparison
+ [ ] is for using <= or >= instead
+ example : { '>time' : 1178531418 }
+ example : { ']event_id' : 2305 }
+ * a field starting with [ or ] means older than or more recent than
+ the associated value should be a given unix timestamp
+ * a (string) value containing either a * or a % character is
+ treated as a (sql) pattern; * are replaced with % that is the
+ SQL wildcard character.
+ example : { 'hostname' : '*.jp' }