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Why are some queries worse than others in MySQL?
Some queries ask for more data than they need and then throw some of it away. This demands extra work of the MySQL server, adds network overhead, [ 36] and consumes memory and CPU resources on the application server. Here are a few typical mistakes:
Is there a slow query logging feature in MySQL?
As discussed in Chapter 2, the standard slow query logging feature in MySQL 5.0 and earlier has serious limitations, including lack of support for fine-grained logging. Fortunately, there are patches that let you log and measure slow queries with microsecond resolution.
How to optimize query performance in MySQL?
These developers are used to techniques such as issuing a SELECT statement that returns many rows, then fetching the first N rows, and closing the result set (e.g., fetching the 100 most recent articles for a news site when they only need to show 10 of them on the front page).
When to use query optimization and index optimization?
If your queries are bad, even the best-designed schema will not perform well. Query optimization, index optimization, and schema optimization go hand in hand. As you gain experience writing queries in MySQL, you will come to understand how to design schemas to support efficient queries.
How can I improve the performance of MySQL?
We often see this in applications designed by people familiar with other database systems.
Is there a microsecond resolution for MySQL?
Fortunately, there are patches that let you log and measure slow queries with microsecond resolution. These are included in the MySQL 5.1 server, but you can also patch earlier versions if needed.
Do you need to pull SQL Server instance information?
When in a rush to quickly pull all the accessible SQL Server instance information, there is no need to execute enormous T-SQL scripts or trying to find some basic information that is buried somewhere into SSMS property windows, especially when those don’t return all that is required.