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In SQL, the TRUNCATE TABLE statement is a data manipulation language (DML) [1] operation that deletes all rows of a table without causing a triggered action. The result of this operation quickly removes all data from a table, typically bypassing a number of integrity enforcing mechanisms.
Inserts are easy too because new rows are appended to the end of the data file. However, delete and update operations are more problematic: deletes must leave an empty space, or the rows' offsets would change; the same goes for updates, as the length of the rows becomes shorter; if the update makes the row longer, the row is fragmented.
MySQL has stand-alone clients that allow users to interact directly with a MySQL database using SQL, but more often, MySQL is used with other programs to implement applications that need relational database capability. MySQL is a component of the LAMP web application software stack (and others), which is an acronym for Linux, Apache, MySQL ...
DELETE requires a shared table lock; Triggers fire; DELETE can be used in the case of: database link; DELETE returns the number of records deleted; Transaction log - DELETE needs to read records, check constraints, update block, update indexes, and generate redo / undo. All of this takes time, hence it takes time much longer than with TRUNCATE
Manage users on the server: add, remove and edit users, and their credentials; Manage user privileges globally and per database; Export databases to SQL files or to other servers; Multiple query tabs, with each one having multiple subtabs for batch results; Server host. View and filter all server variables, such as system_time_zone
Keep in mind, once you remove the username, any data stored for that name on your computer will be deleted, though the actual account may still exist. 1. Click Settings. 2. Click Manage users in the General tab. 3. Select the username you want removed. 4. Click Remove. 5. Click Remove again, then Continue to confirm you really want to remove ...
REVOKE to remove the user accessibility to database object. The operations for which privileges may be granted to or revoked from a user or role apply to both the Data definition language (DDL) and the Data manipulation language (DML), and may include CONNECT , SELECT , INSERT , UPDATE, DELETE , EXECUTE , and USAGE .
MySQL Cluster is implemented through the NDB or NDBCLUSTER storage engine for MySQL ("NDB" stands for Network Database). MySQL Federated – allows a user to create a table that is a local representation of a foreign (remote) table. It utilizes the MySQL client library API as a data transport, treating the remote data source the same way other ...