postgresql-10-similarity binary package in Ubuntu Bionic s390x

 pg_similarity is an extension to support similarity queries on PostgreSQL.
 The extension consists of:
 .
  * Functions implementing similarity algorithms available in the literature.
    These functions can be used as UDFs and are the base for implementing
    the similarity operators;
  * Operators defined on top of the similarity functions. They use similarity
    functions to obtain the similarity threshold and compare its value to a
    user-defined threshold to decide if it is a match or not;
  * Session variables storing similarity function parameters.

Source package