Data type conversion issues

[v3g42]

Reference SQL

  select name, avg(end_time - start_time)/1000.0 as duration, extract(minute from start_time) as minute
  into minute_spans
  from spans
  group by name, extract(minute from start_time);

  select name, avg(end_time-start_time)/1000.0 as duration, extract(hour from start_time) as hour
  into hourly_spans
  from spans
  group by name, extract(hour from start_time);

• [x] #1185
• [ ] Subtraction between timestamps is returning i32. If my duration is in nano or micro seconds, information is lost.
• [x] #1184
• [ ] Timestamp to support nano and micro
• [ ] TypedService cannot convert Float types
• [ ] Can't CAST float to int

 Invalid argument type for function CAST AS INT(): type: float, expected types: int, string, unsigned int, index: 0