What does it mean to cross apply?

CROSS APPLY returns only rows from the outer table that produce a result set from the table-valued function. It other words, result of CROSS APPLY doesn’t contain any row of left side table expression for which no result is obtained from right side table expression.

Does MySQL have cross apply?

The Cross Apply and Outer Apply features are not available in MySQL or PostgreSQL. A feature called Lateral Joins, which is similar, was introduced in MySQL 8.0. 14 and PostgreSQL 9.0.

What is Outer apply in Oracle?

The OUTER APPLY join is a variant of the LEFT OUTER JOIN with correlation support. The usage is similar to the CROSS APPLY join, but it returns all rows from the table on the left side of the join. If the right side of the join returns no rows, the corresponding columns in the output contain NULLs.

How does outer apply work?

OUTER APPLY resembles LEFT JOIN, but has an ability to join table-evaluated functions with SQL Tables. OUTER APPLY’s final output contains all records from the left-side table or table-evaluated function, even if they don’t match with the records in the right-side table or table-valued function.

What is difference between cross join and full outer join?

A full outer join combines a left outer join and a right outer join. The result set returns rows from both tables where the conditions are met but returns null columns where there is no match. A cross join is a Cartesian product that does not require any condition to join tables.

Is Cross apply better than inner join?

While most queries which employ CROSS APPLY can be rewritten using an INNER JOIN , CROSS APPLY can yield better execution plan and better performance, since it can limit the set being joined yet before the join occurs.

What is table valued function?

A table-valued function returns a single rowset (unlike stored procedures, which can return multiple result shapes). Because the return type of a table-valued function is Table , you can use a table-valued function anywhere in SQL that you can use a table.

Is Cross apply faster than inner join?

https://www.youtube.com/watch?v=ImMKZiiM_Yw