How do you optimize MySQL queries effectively

SQL Optimization: Using Indexes Correctly

The world of relational database theory is dominated by tables and sets and operations on those tables and sets. A database is a set of tables and a table is a set of rows and columns. When you use a SELECT query to get rows from a table, you also get a lot of rows and columns. These are abstract concepts that have nothing to do with the representation of the data on which a database system is based for processing your tables. Another abstraction is that the operations on tables are all done at the same time; Inquiries can be thought of as a set of operations, and there is no concept of time in set theory.

In real life, of course, it looks very different. Database management systems implement abstract concepts, but on real hardware and taking into account the real limitations. Inquiries take time - sometimes a lot of time. And because we are impatient beings who cannot wait for anything, we leave the abstract world of immediate mathematical operations in large numbers and look for methods to speed up our queries.

Fortunately, there are options. We put an index on tables so that the database server can find the rows more quickly. We are considering how we can formulate queries in such a way that they can make optimal use of these indexes. We write requests in such a way that the server's scheduling mechanism is used so that requests from different clients can better cooperate. We think about what happens on the hardware used and how we can circumvent its physical limitations and thus improve performance.

This series of articles is about precisely these problems. It should help you to optimize the performance of your database system so that your requests are processed as quickly as possible. MySQL is pretty fast, but even the fastest database can run queries faster if you help it.

Our new series for optimizing MySQL queries is based on Chapter 4 "Optimizing queries" of the standard work "MySQL 4 - Configuration, Administration and Development" by Paul Dubois from the SAMS publishing house. You can find other MySQL books and eBooks by Paul Dubois in our partner bookshop at informit.de.