Block nested loop join

Hi all,

I am new to postgresql. I am currently doing research to optimize the query
performance of RDBMS, specifically postgresql. Hence, I am currently reading
out the code to understand the implementation of various query evaluation
algorithm in postgresql.

Currently, I am investigating the nested loop join algorithm in
nodeNestloop.c. After reading the code, my understanding is that it performs
simple nested loop join (not block nested loop join). Is this true? Does
postgresql support block nested loop join? If it does, where is it? I might
miss some buffering/caching mechanism.

I appreciate any helps/advice.

Regards,

Bramandia R.