ORACLE INTERVIEW QUESTION & ANSWERS
| 16. |
What is a DDL statement? |
| |
A DDL (Data Definition Language) statement is used to manipulate or define the storage in the database. These statements are used to create and destroy tables, tablespaces, datafiles and
so on. |
| 17. |
What is a DML statement? |
| |
A DML (Data Manipulation Language) statement is used to manipulate the actual data that is stored in the database. These statements are used to input, change, delete, or retrieve data
that is being stored in the database. |
| 18. |
What is DCL statement? |
| |
DCL stands for Data Control Language. It consists of commands that control the user access to the database objects. |
| 19. |
Define transaction? |
| |
A transaction is a logical unit of work consisting of one or more SQL statements, ending in a commit or a rollback. Performance measurements often use the number of transactions per second or per
minute as the performance metric. |
| 20. |
What are two ways that you can indicate a comment in a SQL command? |
| |
You can indicate a comment in a SQL command by using /* and */ or by using --.
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