Overview of MySQL Programs There are many different programs in a MySQL installation. This section provides a brief overview of them. Later sections provide a more detailed description of each one, with the exception of MySQL Cluster programs. Each program's description indicates its invocation s...
Password Hashing in MySQL MySQL lists user accounts in the user table of the mysql database. Each MySQL account can be assigned a password, although the user table does not store the cleartext version of the password, but a hash value computed from it. MySQL uses passwords in two phases of clien...
Passwords and Logging Passwords can be written as plain text in SQL statements such as CREATE USER, GRANT, and SET PASSWORD, or statements that invoke the PASSWORD() [1283] function. If these statements are logged by the MySQL server as written, ...
Pattern Matching MySQL provides standard SQL pattern matching as well as a form of pattern matching based on extended regular expressions similar to those used by Unix utilities such as vi, grep, and sed. SQL pattern matching enables you to use “_” to match any single character and “%” to match a...
Performance and Concurrency Considerations for Online DDL Online DDL improves several aspects of MySQL operation, such as performance, concurrency, availability, and scalability: • Because queries and DML operations on the table can proceed ...
Performance of In-Place versus Table-Copying DDL Operations The raw performance of an online DDL operation is largely determined by whether the operation is performed in-place, or requires copying and rebuilding the entire table. See Table 5....
Performance Schema. The Performance Schema includes several new features: • Instrumentation for table input and output. Instrumented operations include row-level accesses to persistent base tables or temporary tables. Operations that affect r...
Postinstallation Setup and Testing After installing MySQL, there are some issues that you should address. For example, on Unix, you should initialize the data directory and create the MySQL grant tables. On all platforms, an important security concern is that the initial accounts in the grant tab...
Primary Key and Secondary Key Indexes Historically, the MySQL server and InnoDB have each kept their own metadata about table and index structures. The MySQL server stores this information in .frm files that are not protected by a transactional m...
Production Releases • MySQL 5.6: Latest General Availability (Production) release • MySQL 5.5: Previous General Availability (Production) release • MySQL 5.1: Older General Availability (Production) release • MySQL 5.0: Older Production release nearing the end of the product lifecycle MySQL 4.1...
