mysql optimizer different results between servers

It shows how a query will be or was executed. If you’re a network guy like me, look at it as the number of hops for packets through a network which data must pass between source and destination.

SQL Server’s query optimizer does an excellent job by generating a physical model of the most efficient route to the data. Such a plan is created when a query is accepted by SQL Server and it’s coming from either an application or it’s coming from us when testing query performance. It’s basically a map that SQL Server is drawing to the shortest ideally the most efficient path to the data in our database. Hopefully, this article will help you if you ever find yourself in a situation when a user gives you a call at 4:30 PM on Friday and says, “this application is too slow” or you just want to test and optimize your queries.Ī query execution/explain plan AKA execution plan is an ordered set of steps used to access data in a SQL Server. Let’s face it, querying data is not just writing Select (*).

This is something that we can design with a focus on query performance, but we can also find and troubleshoot slow performance queries by identifying bottlenecks in them. Therefore, we need to make sure that our queries are performing well. In the database world, this is very important. Often even clicking a single button requires query performance optimization because everything that’s actually happening under the hood is just SQL Server pulling the data from a database.

The SQL Select statement is the primary mechanism to retrieve data from a database. As computers get faster and technology moves forward users get more impatient and want things right now without having to wait. Nobody likes to click a button, go get a coffee, and hope the results are ready. No matter if we’re talking about applications in which users click buttons to display data or if we’re writing a query directly into let’s say SQL Server Management Studio (SSMS).

Mysql optimizer different results between servers