Should you use HASH index?

Today, Mattias|farm on IRC asked how to create primary key using HASH index. After some talk, he said that in some books it said that for “=" (equality) hash indexes are better.

So, I digged a bit deeper.

IMPORTANT UPDATE: As of PostgreSQL 10 hash indexes are WAL logged. As such, main point against them is gone.

Continue reading Should you use HASH index?