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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. To defragment rows and claim empty space, the OPTIMIZE TABLE command must be executed.
Deleting all rows from a table can be very time-consuming. Some DBMS [clarification needed] offer a TRUNCATE TABLE command that works a lot quicker, as it only alters metadata and typically does not spend time enforcing constraints or firing triggers. DELETE only deletes the rows. For deleting a table entirely the DROP command can be used.
Data Control Language is one of the logical group in SQL Commands. SQL [1] is the standard language for relational database management systems. SQL statements are used to perform tasks such as insert data to a database, delete or update data in a database, or retrieve data from a database.
MySQL Workbench 5.0 and 5.1 are specialized visual database design tools for the MySQL database. While MySQL Workbench 5.0 was a MS Windows-only product, cross-platform support was added to MySQL Workbench 5.1 and later.
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.
Create/alter table: Yes - can create table, alter its definition and data, and add new rows; Some - can only create/alter table definition, not data; Browse table: Yes - can browse table definition and data; Some - can only browse table definition; Multi-server support: Yes - can manage from the same window/session multiple servers
Database Workbench supports the following relational databases: Oracle Database, Microsoft SQL Server, SQL Anywhere, Firebird, NexusDB, InterBase, MySQL, MariaDB, SQLite and PostgreSQL [14] [15] [16] Version 6 of Database Workbench is a 64-bit application for Windows platforms, previous versions were 32-bit. [17]
A derived table is the use of referencing an SQL subquery in a FROM clause. Essentially, the derived table is a subquery that can be selected from or joined to. The derived table functionality allows the user to reference the subquery as a table. The derived table is sometimes referred to as an inline view or a subselect.