3 ms·
pls reread my post, I wrote that query select * from A join B on col1=col2 is the the same plan as for select * from a, b where col1=col2 this is true regardl
by slt2021 6y ago
pls reread my post, I wrote that query
select * from A join B on col1=col2 is the the same plan as for
select * from a, b where col1=col2
this is true regardless of schema and statistics, it is simply how query planner works under the hood
and you can check it yourself on any database
- iaabtpbtpnn 6y agoThose are both inner joins, just a different syntax for writing them.
- ohlookabird 6y agoThey might be logically equivalent, but they are not identical if more than two tables are joined. For instance, the current Postgres docs say [1]: > This latter equivalence does not hold exactly when more than two tables appear, because JOIN binds more tightly than comma. For example FROM T1 CROSS JOIN T2 INNER JOIN T3 ON condition is not the same as FROM T1, T2 INNER JOIN T3 ON condition because the condition can reference T1 in the first case but not the second. [1] https://www.postgresql.org/docs/current/queries-table-expressions.html#QUERIES-JOIN https://www.postgresql.org/docs/current/queries-table-expres...