Using Ferret Parameters - Advanced SQL Engine - Teradata Database

The variable, parameter, in the Ferret syntax diagram includes various types of parameters, including multitoken parameters and decimal and hexadecimal numeric input.

Multitoken Parameters

Multitoken parameters, such as subtable identifiers, which are typed as three values, are typed on a single line with one or more spaces separating the individual tokens. You can also enter multitoken parameters separated by hyphens.

For example, either of the following as subtable identifiers is acceptable:

0 200 0
0-200-0

You can separate parameters from each other and from the command by spaces or a comma. To specify a command option (cmdoption ), type it on the same line as the command (cmd).

Numeric Input

Numeric values can be entered in either decimal or hexadecimal format. The default numeric base for data input to and output depends on the radix settings for input and output:

• When the radix for input is decimal, numeric input is interpreted as decimal numbers. For example, input of 45 is interpreted as the value 45.
• When the radix for input in hexadecimal, numeric input is interpreted as hexadecimal numbers. For example, input of 45 is interpreted as the value 69.

The initial radix setting is hexadecimal for input and output. For more information on setting the radix, see the documentation for the RADIX command.

The following special numeric formatting conventions can be used to force entered numeric values to be interpreted as decimal or hexadecimal, regardless of the radix setting:

• Decimal values can be signified by adding a 0i or i prefix, or by adding a decimal point suffix:

  0i45 45. 0I45

• Hexadecimal values can be signified by adding a 0x or x prefix, or by adding an h suffix. Leading zeros are optional:

  0x2D X2D 2Dh 002DH

The valid range of for numeric values is unsigned 16-bit values, 0 through 65535 (0x0 through 0xFFFF), except when patching and using /L or /W for 32-bit integers, in which case the valid range is 0 through 4,294,967,295 (0x0 through 0xFFFFFFFF).

You must separate two numbers on the same line from each other by a space or a comma.

Specifying a Subtable Identifier (tid)

Commands operate on subtables, rather than on tables. A table is a collection of subtables, and a subtable is a collection of physical rows. Each subtable has physical rows that store one particular type of data. For example, primary and fallback data subtables have data rows, primary and fallback index subtables have index rows, and the physical rows of table header subtables contain table metadata.

Each subtable is identified by a subtable identifier ( tid ). The tid has two parts. The first part identifies the table to which the subtable belongs. All subtables that are part of the same table have the same table identifier as part of their tid. The second part identifies one of the subtables that comprise the table, and indicate the subtable type.

A tid is defined as follows:

{ table_unique | = } type_and_index

table_unique and type_and_index together uniquely identify a subtable.

The syntax for type_and _index is as follows:

{ type [ / index [ / variant ] ] | number }

The following table gives examples that describe the type_and _index fields.

For example, assume that table T4 is a table in database MYDB and has a table_number of 0 1198. Also assume that input is accepted in hexadecimal format.

Some valid specifications of a tid for primary subtables of table T4 are as follows:

• "MYDB.T4" 400
• "MYDB.T4" 1024.
• "MYDB"."T4" P
• u 'MYDB'.'T4' 400 h
• 0 1198 400
• 0 1198 P

Classes of Tables

The Teradata Database differentiates among the following five classes of tables. You can specify a table classification when defining the SCOPE parameters of an action.

The attributes associated with each class of tables can affect system performance, since the attributes are set individually, and each class of tables is used for a different purpose.

For example, you might want to pack only Permanent and PJ tables. Therefore, you would specify these tables when defining the SCOPE of the PACKDISK command.

Rows and Row Ranges

A range of rows, also called a ridrange , is specified by the ridspec of the starting and ending rows:

start_rid_spec [ TO end_rid_spec ]

For purposes of input, the required and optional components of a ridspec depend on whether the table containing the physical row is partitioned.

{ row_partition | = } [ { row_hash | = } [ row_unique | = ] ]

{ partitioned_ridspec |
  [ row_partition | = ] { row_hash | = } [ row_unique | = ] 
}

For more information on the Teradata Database File System and physical rows, see The Teradata Database File System.

For more information on table row structure, see Teradata Vantage™ - Database Design, B035-1094.

Vproc Numbers

In Ferret, the vproc number (vproc_number) is used in the SCOPE command to specify one AMP or a range of AMPs for which the utility performs an action, such as reconfiguration or disk space display.

Valid AMP vprocs have numbers in the range of 0 through 16199.

Map Names

A map includes one or more AMP vprocs. If you specify a map name in the Ferret SCOPE command, the name must be enclosed with double quotation marks. The scope is effectively the same as if you had scoped Ferret to the individual vprocs that are included in the specified map.