joins

[kalaivanan]

hi dis is kalaivanan,
which one of inner join or left join is efficient and in what way.

[David Portas]

kalaivanan wrote:

hi dis is kalaivanan,
which one of inner join or left join is efficient and in what way.

Inner joins and outer joins achieve different results so in general it
won't make sense to compare them on performance.

In cases where an inner and outer join are guaranteed to give the same
result I suggest you test it out for yourself. Performance is too
heavily dependent on other factors for there to a be a single, simple
answer.

--
David Portas, SQL Server MVP

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--

[Erland Sommarskog]

David Portas (RE****************************@acm.org) writes:

In cases where an inner and outer join are guaranteed to give the same
result I suggest you test it out for yourself.

And in that case, I expect the optimizer to see that the left join is
really an inner join, and thus you would get the same query plan.

The question is simply not meaningful, since, as David pointed, the
difference lies in functionality.
--
Erland Sommarskog, SQL Server MVP, es****@sommarskog.se

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