16.10 - CI - Teradata Database

Teradata Database Support Utilities

prodname
Teradata Database
vrm_release
16.10
created_date
June 2017
category
Configuration
featnum
B035-1180-161K

Purpose

The CI (Cylinder Index) command accesses the latest copy of the CI for the given cylinder and formats it in accordance with the display options.

Syntax

The online help lists the display options (/P, /S, /M, /L, /X, /H, /V) as /dispopt. You can type the options at the beginning or end of the command.


/P
Positions to this CI. If this cylinder is not a file system cylinder, an error occurs. Nothing is displayed unless a problem occurs.
/S
Shows a formatted display of the following:
  • header and trailer.
  • first and last DBDs.
  • first and last SRDs.
/M
Shows a formatted display of the following:
  • header and trailer.
  • all of the SRDs, with each one followed by the first and last DBDs for that SRD.
/L
Shows a formatted display of the following:
  • header and trailer.
  • all of the SRDs, with each one followed by all of the DBDs for that SRD.
  • the Free Sector (FSE) and the Unfree Sector (UNFSE) lists, if they exist.
/X
Shows the same display as /L, but also include the timestamp and other details from the DB for each DBD.
/H
Shows a hexadecimal dump of the requested CI.
/V
Verifies that the CI is logically correct, but does not display it.
FORCE
Formats as CI even if the block code indicates otherwise. Without FORCE, the command fails on a mismatched block.
FIX
Filer will attempt automatic repair of the CI. You must supply the /V option with the FIX option, and the Teradata Database must be down.
cylid
The 64-bit identifier of a cylinder, entered as a 16-character hexadecimal number.
=
Filer will use the most recently saved value for cylid.
This option cannot be used unless input value has already been defined for cylid. For more information, see Stored Input Values.

Usage Notes

If the segment acquired is not a CI, then an error occurs unless you specify FORCE, in which case Filer will attempt to format the block as a CI.

The CI command output displays additional columns for the CI checksum (checksum), checksum algorithm (ag), and checksum sample count (ct) fields in the CI header if the CI currently has an associated checksum. The checksum and checksum algorithm are in both the CID and the CI, providing both internal and external checksums. The count is only in the CI and is used for either an internal or an external check.

In addition, the checksum, checksum algorithm, and checksum sample count fields contained in the DBD structure are displayed for each DBD listed. The addition of these three checksum fields to the DBD structure expands the width of the DBD display from 88 to 105 characters.

The value of the checksum sample count field is a byte in the range 0 – 128. This number corresponds to the number of 32-bit words to sample per disk sector in the file system block.

The CI is stored on the first n sectors of each cylinder and describes only that cylinder. The CI has a redundant copy immediately following it on the disk. The CI can reside in one of two places:

  • Disk
  • DRAM

The default access is the latest copy of the CI.

The prompt for this selection is as follows:

CI ==>

The following commands are allowed at the CI prompt:

  • Lower-level commands DELETE, DISPLAY, NEXT, PACK, PATCH, PREV, TRASH, AND WRITE. Although the current object selected can be the latest CI, the redundant CI, an SRD, or a DBD, the prompt reflects the current object. NEXT and PREV always access the latest copy of the next or previous CI. To get to the next or previous CI, when at an SRD or DBD object, type one of the following:
    • CI =; NEXT
    • CI =; PREV

    The display options for any of these commands are the same as that of the currently selected object, either the CI or the SRD, and makes no difference on a DBD.

  • Upper-level commands that switch Filer to another object or level within the file system.
  • Global commands, which include DATE, DISABLE, ENABLE, ERRORS, HELP, INPUT, OUTPUT, QUIT, RADIX, and SHOWDEFAULTS.