what is Hash join?how it is different from inner join?what
is the sign used for inner join?(eg: like the (+) sign used
for outer join)?

Answer Posted / anil kumar jaiswal

Hash Join : When there is no index available on join columns and both table has huge amount of data then oracle optimizer will pick hash join automatically.

we also have use_hash hints in oracle to instruct oracle optimizer to perform hash join on the given Query.

check explain plan for any query to see the join performed on that particular query.

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