24. Teradata Database

A Teradata Database

A database provides a logical grouping of information (tables, views, and

macros). A database could be considered a passive repository, because it

is used solely to store other database objects. This is different from a user,

which we will learn about on the next page.

Perm Space

All databases have a defined upper limit of

Permanent Space.

Permanent Space is used for storing the data rows of tables. Perm Space

is not pre-allocated. It represents a maximum limit.

Spool Space

All databases also have an upper limit of

Spool Space. If there is no limit

defined for a particular database or user, limits are inherited from parents.

Theoretically, a user could use all unallocated space in the system for

their query. Spool Space is Temporary Space used to hold intermediate

query results or formatted answer sets to queries. Once the query is

complete, the Spool Space is released.

Example

: You have a database with total disk space of 100GB. You have

10GB of user data and an additional 10GB of overhead. What is the

maximum amount of Spool Space available for queries?

Answer

: 80GB. All of the remaining space in the system is available for

spool.

Temp Space

The third type of space is

Temporary Space. Temp Space is used for

global temporary tables, and these results remain available to the user

until the session is terminated. Tables created in Temp Space will survive

a restart. Temp Space is permanent space currently not used.