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Is it slow to use two inner joins in SQL?
It will be very very very slow. If you change that query to use two inner joins instead of a left join, it will be very fast. If you change it to use two left joins instead of an inner join, it will be very fast. You can observe this same behavior if you use a sql table variable instead of the freetexttable as well.
Why is MY SQL Server query so slow?
If you execute this query: It will be very very very slow. If you change that query to use two inner joins instead of a left join, it will be very fast. If you change it to use two left joins instead of an inner join, it will be very fast.
Which is faster cross apply or inner join?
It’s important to note, however, that the CROSS APPLY does not always perform faster than an INNER JOIN. In many situations, it will probably be about the same. In rare cases, though, I’ve actually seen it slower (again, this all depends on your table structure and the query itself).
Why is query running slow on nested loops?
Also note that in production, the temp table #Ids doesn’t exist, it’s a Table Valued Parameter of the same 10’000 Ids passed on to the Stored Procedure. As pointed out by the accepted answer, the problem was the OR clause in the category_link JOIN. However, the code suggested in the accepted answer is very slow, slower even than the original code.
How does inner join affect number of rows?
A general rule of thumb is that OUTER JOINs cause the number of rows in a result set to increase, while INNER JOINs cause the number of rows in a result set to decrease. Of course, there are plenty of scenarios where the opposite is true as well, but it’s more likely to work this way than not.
Why is SQL Server count so slow to query?
So for a high number of rows it will be slow. If you do this operation frequently, the best way is to keep the count record in another table. If however you do not want to do that, you can create a dummy index (that will not be used by your query’s) and query it’s number of items, something like: