The indexes on a the tables of a large database make a huge difference in its performance and utility. Without an index, locating a single record in a large table can take several seconds; with the ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...

SQL is a convenient way to manage and query your data, but badly written queries can tie up your database. Here are seven common SQL traps and how to avoid them. Database developers have it tough.