Cylindrical & Master index

Database
N/A

Cylindrical & Master index

What are exactly master & cylindrical index mean?

I believe these are to identify to row in a data block from AMP and are not to be specified explicitly.

Please elaborate.

Thanks!
Mahesh.
4 REPLIES
Teradata Employee

Re: Cylindrical & Master index

For a discussion of master and cylinder indexes, see the Teradata Database: Database Design manual (chapter 9). They are not specified explicitly -- they are used to internally maintain and search the hashed organization of data on an AMP.

The master index is a memory-resident file system data structure that contains pointers to
every cylinder index on a given AMP in entries referred to as Cylinder Index Descriptors, or
CIDs. When a cylinder does not contain data, it is not listed in the master index.

The cylinder index is a disk-resident file system file structure that contains Master Index
substructures referred to as Data Block Descriptors, or DBDs. Each disk cylinder has its own
cylinder index. The structure contains pointers to all the data blocks and free sectors on the
cylinder it represents.
N/A

Re: Cylindrical & Master index

Thanks paul.

Let me take opportunity to ask one more question.

If i want to understand how optimizer creates execution plan for queries containing complex joins be it merge,product or outer joins(Joins may or may not based on indexes) also containing CASE statements etc.

Would you suggest me some manual for this?

waiting for your reply.

Thanks,
Mahesh.
Teradata Employee

Re: Cylindrical & Master index

A good starting place for this is Teradata Database: SQL Request and Transaction Processing, Chapters 1 to 5. Teradata manuals can be found at http://www.info.teradata.com/
N/A

Re: Cylindrical & Master index

My guess was right.Thanks a lot paul.

Mahesh!