Is there any efficiency difference in an explicit vs implicit inner join?
For example:
SELECT * FROM
table a INNER JOIN table b
ON a.id = b.id;
vs.
SELECT a.*, b.*
FROM table a, table b
WHERE a.id = b.id;
Is there any efficiency difference in an explicit vs implicit inner join?
For example:
SELECT * FROM
table a INNER JOIN table b
ON a.id = b.id;
vs.
SELECT a.*, b.*
FROM table a, table b
WHERE a.id = b.id;
Performance wise, they are exactly the same (at least in SQL Server).
PS: Be aware that the IMPLICIT OUTER JOIN
syntax is deprecated since SQL Server 2005. (The IMPLICIT INNER JOIN
syntax as used in the question is still supported)
Deprecation of “Old Style” JOIN Syntax: Only A Partial Thing