Database Redesign Before any changes to database structure are attempted one should first: test any changes on a test database only. All of these clearly understand the current structure and contents of the database only. create a complete backup of the operational database only. test any changes on a test database only. All of these clearly understand the current structure and contents of the database only. create a complete backup of the operational database only. ANSWER DOWNLOAD EXAMIANS APP
Database Redesign Which of the following modifications may not succeed? Both of the above actions should succeed Changing a column data type from numeric to char Neither of the above actions will succeed Changing a column data type from char to date Both of the above actions should succeed Changing a column data type from numeric to char Neither of the above actions will succeed Changing a column data type from char to date ANSWER DOWNLOAD EXAMIANS APP
Database Redesign How can you find rows that do not match some specified condition? NOT EXISTS Double use of NOT EXISTS EXISTS None of these NOT EXISTS Double use of NOT EXISTS EXISTS None of these ANSWER DOWNLOAD EXAMIANS APP
Database Redesign A regular subquery can be processed: None of these from the bottom up. from the top down. by nesting. None of these from the bottom up. from the top down. by nesting. ANSWER DOWNLOAD EXAMIANS APP
Database Redesign What SQL command can be used to add columns to a table? MODIFY TABLE TableName ADD COLUMN ColumnName ALTER TABLE TableName ADD COLUMN ColumnName ALTER TABLE TableName ADD ColumnName MODIFY TABLE TableName ADD ColumnName MODIFY TABLE TableName ADD COLUMN ColumnName ALTER TABLE TableName ADD COLUMN ColumnName ALTER TABLE TableName ADD ColumnName MODIFY TABLE TableName ADD ColumnName ANSWER DOWNLOAD EXAMIANS APP
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