FAQs(1 to 15)

DBADM - Database administrator authority

DBCTRL - Database control authority

DBMAINT - Database maintenance authority

CREATETS - Create Table space Authority

CREATETAB - Create Table authority

DROP - Drop authority on a database or subordinate objects

1) What RDMS objects are created with the SQL CREATE statements?

A) The SQL CREATE statements are used to create the following objects:

STOGROUP A storage group

DATABASE A logical collection of tables

TABLESPACE An area that stores tables

TABLE A data structure organized by a specified columns

INDEX An alternate path to a table data

VIEW An alternate representation of one or more tables

SYNONYM An alternate name for local table or view

ALIAS An alternate name for a table definition which may be local or remote, existence or nonexistent

2) What RDMS objects are required before you can create a table?

A) Before you can create a table, you need an existing database and tablespace.

3) In what RDMS object does one first list column names?

A) One first uses the column name in the CREATE TABLE statement.

4) What is the syntax for a CREATE TABLE statement?

A) CREATE TABLE table name

(column name list

primary key (column name))

in database-name, tablespace-name.

5) Can one add columns to a table after it has been defined?

A) Yes, one can add column to a table after it has been defined by using the SQL ALTER TABLE statement.

6) Where in a table are added columns located?

A) The new columns are added to the end of the table.

7) After a table is defined, can columns be removed?

A) The only way to remove columns from an existing table involves a   migration program that extracts only the desired

columns of data, redefining the table without the unwanted columns, then populating the new table. One have to handle

all the old table?s dependents programmatically.

8) Which RDMS objects can you change with the SQL ALTER statements?

A) The SQL ALTER statement can change a table index, a table, a tablespace, or a STOGROUP.

9) What authority is required to create a table?

A) In order to create tables, one needs CREATETAB privileges.

10) What is minimum authority required for one to create a tablespace?

A) In order to create tablespaces, one needs CREATETS privileges.

11) When is it necessary to create a table index?

A) It is necessary to create a table index whenever you want to enforce the uniqueness of the table?s primary key.

12) What is a synonym?

A) A synonym is an unqualified alternative name for a table or view.

13) What is a foreign key?

A) A foreign key is the key defined in one table to reference the primary  key of a reference table. This foreign key must

have the same structure as the reference table?s primary key.

14) What is referential integrity?

A) Referential integrity is the automatic enforcement of referential constraints that exist between a reference table and a

referencing table. When referential integrity is enforced, the value of a foreign key exists as a primary key value in the

reference table. In other words, when referential integrity is enforced, all of the foreign key values in, for example, the

?department code? column in an ?employee? table exist as primary key values in a ?department? table.

15) What are the column name qualifiers?

A) A column name qualifier are used as a table designator to avoid ambiguity when the column names referenced exists

in more than one table used in the SQL statement. Column name qualifiers are also used in correlated references.