database

Problem:

start postgresql as usual

 

pg_ctl -w -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

Output :

 

waiting for server to start.... stopped waiting
pg_ctl: could not start server
Examine the log output. 

Open the log file to identify the problem

vi /usr/local/var/log/server.log 

Log file error 

PostgreSQL treats LEFT JOIN and NOT EXISTS equally, using same execution plan for both of them (namely a Hash Anti Join for the example above).

As for NOT IN, which is semantically different since its logic is trivalent and it can return NULL, PostgreSQL tries to take this into account and limits itself to using a filter against a subplan (a hashed subplan for a hashable resultset like in example above).