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Is exists better than inner join?
If you do an inner join on a recordset with DISTINCT applied (to get rid of the duplicates), EXISTS is usually faster. IN and EXISTS clauses (with an equijoin correlation) usually employ one of the several SEMI JOIN algorithms which are usually more efficient than a DISTINCT on one of the tables.
Which is better exists or join?
In most cases, EXISTS or JOIN will be much more efficient (and faster) than an IN statement. With an EXISTS or a JOIN, the database will return true/false while checking the relationship specified. Unless the table in the subquery is very small, EXISTS or JOIN will perform much better than IN.
Which will execute fast in or exists?
The EXISTS clause is much faster than IN when the subquery results is very large. Conversely, the IN clause is faster than EXISTS when the subquery results is very small. Also, the IN clause can’t compare anything with NULL values, but the EXISTS clause can compare everything with NULLs.
Which is better in, exists or inner join?
Most annoying answer is, it depends. Generally speaking JOINs are much better than EXISTS & EXISTS is better than IN, performance wise. If your result set is small then you can use IN or EXISTS. But if result set contains a large set of records, then use JOINS. Gail Shaw has a nice write up about this problem in her blogs:
When to use distinct or inner join in Excel?
If you have multiple Results for an Institution, doing the INNER JOIN will return multiple rows for that institution. You could get around that by using DISTINCT, but then the EXISTS will probably be better for performance anyway.
Which is better join or exists in SQL?
Unlike EXISTS, JOIN isn’t as confusing to implement. The downside to JOIN is that if the subquery has any identical rows based on the JOIN predicate, then the main query will repeat rows which could lead to invalid query outputs. Both IN and EXISTS will ignore duplicate values in a subquery.
Can you use inner join with where clause?
In addition, the relational algebra allows interchangeability of the predicates in the WHERE clause and the INNER JOIN, so even INNER JOIN queries with WHERE clauses can have the predicates rearranged by the optimizer. I recommend you write the queries in the most readable way possible.