Search results
Results From The WOW.Com Content Network
DROP TABLE table DROP INDEX name Multiple statements may be executed in one cursor.execute(S) by separating the statements with semicolons in S, for example S might have the string value: DROP INDEX tdindex ; DROP TABLE templikes
The DROP statement destroys an existing database, table, index, or view. A DROP statement in SQL removes a component from a relational database management system (RDBMS). The types of objects that can be dropped depends on which RDBMS is being used, but most support the dropping of tables, users, and databases.
SQL-92 was the third revision of the SQL database query language. Unlike SQL-89, it was a major revision of the standard. Aside from a few minor incompatibilities, the SQL-89 standard is forward-compatible with SQL-92. The standard specification itself grew about five times compared to SQL-89.
The SQL standard classifies TRUNCATE as a data change statement, synonymous with data manipulation (DML). This aligns with TRUNCATE being logically equivalent to an unconstrained DELETE operation. However, some documents describe TRUNCATE as a data definition language (DDL) operation, because TRUNCATE may be seen as a combined DROP+CREATE ...
A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.
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; reduces performance during execution - each record in the table is locked for deletion; DELETE uses more transaction space than the TRUNCATE statement
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Create new, alter existing databases' name, character set and collation, drop (delete) databases; Tables, views, procedures, triggers and events. View all objects within the selected database, empty, rename and drop (delete) objects; Edit table columns, indexes, and foreign keys. Virtual columns on MariaDB servers are supported.