15.00 - ALTWCI - Teradata Database

Teradata Database Support Utilities

prodname
Teradata Database
vrm_release
15.00
category
Configuration
featnum
B035-1180-015K

ALTWCI

Purpose  

There are two copies of each WCI, only one of which is active at any time. The active copy reflects the current state of the WAL cylinder. The ALTWCI command makes the non-active copy the active copy, and the formerly active copy the non-active copy.

Note: This command can be used only when Teradata Database is not running on the affected AMP.

Syntax  

 

Syntax Element

Description

cylid

The 64-bit identifier of a cylinder, entered as a 16‑character hexadecimal number.

Usage Notes  

ALTWCI can be used only when the scope is set to one vproc. For more information on the SCOPE command, see “SCOPE (or VPROC)” on page 206.

Caution:

Picking the alternate copy of a WCI might result in overlapping record numbers across cylinders and mismatches between the WCI and the blocks on the associated cylinder. After performing this command, use scandisk to determine whether additional repairs are required.

Example  

Filer ==>
scope vproc 0

Command has been sent to Slave tasks.
Tue Jul 03, 2007 16:47:39

 1 of 8 amps have been selected

Filer ==>
altwci 0 2A

Active WCI
---------
Location: PRIMARY
Blk Code:  WCI
Version Number: 19
WLSN                : (0000000000024E32)
Stamp               : Wed Jul 11, 2007 15:28:36.51 (64 2F 95 46 33)

Non-Active WCI
-------------
Location: SECONDARY
Blk Code:  WCI
Version Number: 3
WLSN                : (000000000000AF68)
Stamp               : Tue Jul 03, 2007 10:51:10.01 (5E 62 8A 46 01)

*** WARNING ***
Picking the alternate copy of a [W]CI might result in overlapping
tableids/rowids across cylinders and mismatches between the [W]CI
and the blocks on the associated cylinder. After performing this
command, use scandisk to determine whether additional repairs are
required.
*** WARNING ***


Do you want to switch the active copy to the alternate copy? (Y/N)
> y
y


Active WCI
---------
Location:  SECONDARY
Blk Code:   WCI
Version Number: 3
WLSN                : (000000000000AF68)
Stamp               : Tue Jul 03, 2007 10:51:10.07 (5E 62 8A 46 07)


Successfully alternated the WCI.