0 - 3 of 3 tags for explain terminology

Could you please suggest how to avoid this product join step and explain about this step.
Usually how should i understand this kind of steps all stats seems to be up to date on these columns.

While testing the 13.10 version of the DBMS on our staging system, we found a query that performs much better under 13.10 and is using a "Group AMP Join", where the 12.0 version Explain plan references something completely different.  I am not familiar with the Group AMP Join and have been unsuccessful finding it in the 13.10 documentation searches I have

A topic that is essential for all SQL programmers and database designers. This session examines the mysteries of the English text that appears when an EXPLAIN is requested.