Functions, aggregates, and user types

Query system_schema functions, aggregates, and types tables to get information about user-defined functions, user-defined aggregates, and user-defined types.

• Show one user-defined function in the system_schema.functions table.

  SELECT *
  FROM system_schema.functions
  LIMIT 1;

  The following output shows the first record using the cqlsh EXPAND ON option.

  @ Row 1
  ----------------------+------------------------------------------------------------------------------------------------------------------
  --------------------------------------------------------
   keyspace_name        | cycling
   function_name        | avgfinal
   argument_types       | ['frozen<tuple<int, bigint>>']
   argument_names       | ['state']
   body                 | \n      double r = 0; \n      if (state.getInt(0) == 0) return null; \n      r = state.getLong(1); \n      r /= s
  tate.getInt(0); \n      return Double.valueOf(r);\n    
   called_on_null_input | True
   deterministic        | False
   language             | java
   monotonic            | False
   monotonic_on         | []
   return_type          | double
  
  (1 rows)

• List the schema settings for one user-defined aggregate.

  SELECT *
  FROM system_schema.aggregates
  LIMIT 1;

  @ Row 1
  ----------------+----------------------------
   keyspace_name  | cycling
   aggregate_name | average
   argument_types | ['int']
   deterministic  | False
   final_func     | avgfinal
   initcond       | (0, 0)
   return_type    | double
   state_func     | avgstate
   state_type     | frozen<tuple<int, bigint>>
  
  (1 rows)

• Show the schema settings for one user-defined type.

  SELECT *
  FROM system_schema.types
  LIMIT 1;

  @ Row 1
  ---------------+-------------------------------------------------
   keyspace_name | cycling
   type_name     | basic_info
   field_names   | ['birthday', 'nationality', 'height', 'weight']
   field_types   | ['timestamp', 'text', 'text', 'text']
  
  (1 rows)