Database size estimation

Database
Enthusiast

Database size estimation

Hi Experts,

Just need a suggestion from you all as to how we can estimate a Teradata Database size for a new Database. The way i see it for a new database to be created and if we have to provide an estimate on the basis of the source Data base table structures

we go for ROW SIZING ==> BASE TABLE SIZING ==> all the table sizes combine to form a the DB size in terms of space occupied by the tables. There are other factors which we consider like no of rows expected in each table and no of days for which the data will be initially loaded and all.

Generally a DB size is estimated as per the below formula:

Tables + Fallback  +

Secondary Indexes + Fallback +

Reference Indexes + Fallback  +

Join Indexes + Fallback  +

Hash Indexes + Fallback  +

Permanent Journal (dual or single)  +

Stored Procedure space  +

Spool space  +

Temporary space

I have taken care of all the details as per the Database design book to come up with the Base Table sizes. But for an initial database we generally do not consider the below sizes (pardon me if I am wrong) since we really don't have any idea about the usage of data that early.

Secondary Indexes + Fallback +

Reference Indexes + Fallback  +

Join Indexes + Fallback  +

Hash Indexes + Fallback  +

Permanent Journal (dual or single)  +

Stored Procedure space

So, the rest is Spool Space and Temporary space. Can I have a brief idea about ideally what should be the Spool Space and Temporary space considering the below factors:

No of amps : depends

Block Size: 64000

Table Header Size : 1024

Combined table size : 5 TB

And also if someone can give me some pointers about the way we estimate the Spool and temporary space.

Would appreciate any help in this regard.

Thanks

Manik