Teradata Space Management

Teradata Space Management

There is no concept of table space in Teradata. There are three different types of space defined in Teradata- 
Perm Space
Spool Space 
Temp Space

1. Perm Space : As the name suggests, perm space is the space which is allocated to define the maximum limit for all databases. It is used to hold all the data of the databases. This space isn’t pre-allocated. 

2. Spool Space : Spool space is used to hold data for Intermediate Query results. Once the query is complete, the space is released. It only holds data. It is active up to the current session only. Spool space is same as that of the root, unless specified. If there is no limit defined for a particular database or user, limits are inherited from parents. In theory, a user could use all unallocated space in the system for their query. The best way to estimate spool usage is to run explains on all of your queries. Just remember that this is an estimate of spool usage not the actual spool usage.

3. Temp Space : Temporary space is the amount of space which can be used to create temporary tables - either volatile tables or global temporary tables. Data is active up to the current session only. Tables created in Temp Space will survive a restart. Temp Space is permanent space currently not used.

Difference between CurrentPerm, MaxPerm and PeakPerm: Maxperm: Maxperm is the total permanent space specified for that user/database.In other words, MaxPerm is the total amount of bytes available for data storage in a database. PeakPerm: PeakPerm is the maximum permspace ever utilised after it has been last reset.In other words, PeakPerm is the peak amount of bytes that have ever been stored in a database.Currentperm : Currentperm is the current space which is being utilized by database/user/table.In other words, CurrentPerm is the actual amount of used bytes in a database.

NOTE: Teradata’s Spool and Temp Space is the perm space that is not currently being used.