4 окт. 2010 г. · I would EXPECT the first query to be quicker, mainly because you have an equivalence and an explicit JOIN. In my experience IN is a very slow operator.

5 апр. 2010 г. · A general rule is that joins are faster in most cases (99%). · The more data tables have, the subqueries are slower. · The less data tables have, ...

10 мар. 2011 г. · The first approach, with joins, is by far faster. In second the query will be executed for each row. Some databases optimize nested queries ...

27 дек. 2012 г. · Usually joins will work faster than inner queries, but in reality it will depend on the execution plan generated by SQL Server.

15 мар. 2019 г. · A correlated sub-query or a "with" clause can be much faster; depending on the sizes of the tables, how many rows are selected from each table, etc.

20 мая 2010 г. · The main difference betwen subquery and join is subquery is faster when we have to retrieve data from large number of tables.

25 апр. 2021 г. · They are both correct. Performance questions need to be tested on your data on your system. However, with a primary key on employee(id) ...

8 мар. 2017 г. · Performance of Sub query vs join · You're comparing estimates and actuals. · The execution timings aren't really helpful as they can be affected ...

22 окт. 2015 г. · It generally won't make any difference, because they should result in the same query plan. At least, an EXISTS subquery will; ...

30 мая 2020 г. · These do different things. The equivalent of the first query is a left join, not an inner join. And then they are only equivalent if you can ...