Ed Loehr wrote:
> Are there any known consequences of forbidding nestloop joins? Performance
> hits? Functionality hits?
OK, I pulled out my old RDBMS text. Here are my current assumptions re join
strategies:
1) The only Pgsql alternative join strategies to nested-loop joins are merge
join and hash join.
2) Merge join only makes sense if the data is physically ordered by the join
keys, and there is almost always a natural entropy away from physical sort
order.
Therefore, it generally makes sense to use only hash join.
Are my assumptions correct? Reasonable conclusion?
Can I configure psql to use only hash joins?
Cheers,
Ed Loehr
