Books
in black and white
Main menu
Share a book About us Home
Books
Biology Business Chemistry Computers Culture Economics Fiction Games Guide History Management Mathematical Medicine Mental Fitnes Physics Psychology Scince Sport Technics
Ads

Teradata RDBMS Database Administration - NCR

NCR Teradata RDBMS Database Administration - NCR , 2004. - 616 p.
Download (direct link): teradatadatabaseadmin2004.pdf
Previous << 1 .. 17 18 19 20 21 22 < 23 > 24 25 26 27 28 29 .. 218 >> Next


Warning: Do not lose the password for user DBC because only DBC can modify it!

Teradata RDBMS Database Administration

1 - 7 Chapter 1: Database Hierarchy

Administrative User

To ensure perm space is from the administrative user, logon as that user to add other users and databases.

All space in the Teradata RDBMS is owned. No disk space known to the system is unassigned or not owned.

Think of a user as a database with a password. Both may contain (or "own") objects such as tables, views and macros. Both users and databases may hold privileges. Only users may logon, establish a session with the Teradata RDBMS, and submit requests (see "Databases versus Users" on page 1-9).

Unused permanent space (that is not allocated to an object) is available for spool. To ensure that spool space is always available, create a special spool reserve database under the SysDBA database, which is not used to load tables. Enter the following statement:

CREATE DATABASE Spool_Reserve AS PERM = xxxx where xxxx is 15-20% of total available space.

Note that SysDBA is designed to be used by customer System Administrators/DBAs.

For more information on spool space, see "Specifying Spool Space Limits" on page 3-6.

1 - 8

Teradata RDBMS Database Administration 1 - 7 Chapter 1: Database Hierarchy

Databases versus Users

Databases versus Users

Permanent space allocated to a Teradata user or database is a uniquely defined, logical repository for:

Data tables

Permanent journals |

Table headers of global temporary tables (one header row per table)

Secondary indexes (SIs)

Join indexes (JIs)

Hash indexes (HIs)

Stored procedures

Triggers

When an object is created or data rows are inserted, the space is allocated from the permanent space of the owning database or user.

A user or database also establishes ownership of entities that have permanent definitions in the Data Dictionary but do not consume permanent space:

Views

Macros

Spool space holds intermediate query results or formatted answer sets to queries. The system can use unassigned permanent space for spool space.

A Database/User definition allows you to set space limits. You specify in each CREATE or MODIFY DATABASE/USER the maximum limit of PERM and SPOOL space to be allocated to your application databases and users. PERM size may be zero if a database is used just to establish ownership and privileges (see Chapter 3: "Space Considerations").

A user is usually associated with a password and has implicit or can be granted explicit access privileges. These parameters are not applicable to a database.

A comparison of objects associated with a database and user includes:

1 - 10 Teradata RDBMS Database Administration

Chapter 1: Database Hierarchy

Databases versus Users

Object or Parameter Database User
Database or User repository Passive. A database can have some privileges but cannot be used to log on, submit queries or commands, or take action in any way. Active. A user can log on to Teradata RDBMS and initiate a session. Users can submit SQL statements to create, modify, and drop objects, insert, update, and delete data, execute macros and stored procedures, query data, initiate logging activities, enter utility commands, and otherwise take action. Once the DBA has granted a user the privileges to CREATE/DROP DATABASE/USER, that user also can create other databases and users.
Hash, join, secondary Indexes Not mandatory. Indexes are associated with a data table and thus with a Database/User, but a data table is not required to have a join, hash, or secondary index. The system cannot store the rows of a data table or its index subtable until permanent space is assigned to the owning database/user.
Macros Not mandatory. Macros must be associated with a Database/User but a Database/User is not required to have macros.
Password N/A Required, except when your site is set up for: Single Sign On (SSO) (Windows 2000 only). For details, see "CREATE USER and Logon Security" on page 5-6 and Teradata RDBMS Security Administration. Security that accommodates GRANT LOGON ... WITH NULL PASSWORD. For instructions and cautions, see "Logon Policy" under "Controlling Access", Teradata RDBMS Security Administration. On channel-connected systems, logon with null password also requires a TDP exit. For details, see "Programming Logon and Security Exits in the Teradata Director Program (TDP)" on page 6-25.

1 - 10

Teradata RDBMS Database Administration Chapter 1: Database Hierarchy

Databases versus Users

Object or Database User
Parameter
Account N/A Every session must have one, but specifying one is
logon string not mandatory; if none is given, the default is used. Account string options include: Session priority scheduling Account identifiers Account String Expansion (ASE) time reporting Session measurements by account ID For details, see "Defining Accounts" on page 5-20.
Previous << 1 .. 17 18 19 20 21 22 < 23 > 24 25 26 27 28 29 .. 218 >> Next