16.10 - About Setting Data Block Sizes Using the DBS Control Utility - Teradata Database

Teradata Database Administration

Product
Teradata Database
Release Number
16.10
Release Date
April 2018
Content Type
Administration
Publication ID
B035-1093-161K
Language
English (United States)

You can set data block sizes globally using these DBSControl fields: PermDBAllocUnit, PermDBSize, and JournalDBSize. These fields determine the maximum size of permanent data blocks that hold multiple rows. (A row that exceeds the size of a multirow data block is put into a block of its own.)

Example of Changing PermDBSize

To change the PermDBSize, you need to use the modify and write commands of the DBS Control utility. The following example changes the data block size to 254 sectors:

  1. From the command-line prompt (or the Supervisor window of the Database Window):
    dbscontrol
  2. From the DBS Control window:
    display FILESYS
  3. Use the modify command to change flag 3 (PermDBSize):
    modify FILESYS 3 = 254
  4. Write the changes to the GDO:
    write
The default and minimum data block size depends on the cylinder size your site uses. Cylinder size is a global value, shown as:
  • Number of Disk Blocks Per Cylinder, using the PUT utility
  • SectsPerCyl, using the Filer utility FIB or SEGZERO command
    By default, Filer returns output from every vproc.