Types of Space's in Teradata

DBC owns all the Disk Space

• When the system arrives DBC owns all the Disk Space.
• Each AMP will have one virtual disk, really four physical disks, which that AMP can read and write, but no other AMP can read or write to or from another AMPs virtual disk.
• Add up all the AMPs disks and you will know how much space DBC originally owns.
• This space is called PERMANENT Space, or PERM SPACE.
• DBC will first CREATE a USER or a DATABAS.

Types of space in Teradata

• There are three types of space in Teradata. They are called PERM Space, SPOOL Space and TEMP Space.
• Perm Space is for Permanent Tables, Spool Space is used to temporarily build Answer Sets when users run queries, and Temp Space is used to CREATE and Populate Global Temporary tables.
• In actuality Spool Space and Temp Space is unused PERM Space.
• Most users don’t get their own PERM space.
• All users get Spool Space. Without Spool Space the users couldn’t run queries.
• Simply remember that Perm is for your Tables and Data and that Spool is used as space for Users to run queries.
• Tables, Join Indexes, Permanent Journals, Hash Indexes, Stored Procedures and User Defined Functions (UDF) require Perm Space.
• Views, Macros and Triggers don’t require Perm space.

Spool is like a Speed Limit

• Teradata definitely has its limits and these pertain to Spool space.
• The Teradata police will abort your query if at any time you go 1 byte over 20 GBs.
• Think of PERM Space like money, but think of Spool Space like a speed limit.
• If the database MRKT is assigned 20 GBs of Spool then that is MRKT’s speed limit. Each user can run queries that travel up to 20 GBs. This goes for all users in MRKT.

Spool is designed for two purposes.

1. Users have a limit so they can’t hog the system resources.
2. If users make a mistake and run a runaway query the system will abort it after it reaches that users spool limit.