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Introduction to the Teradata® RDBMS for UNIX® Version 2 Release 2.1 - NCR

NCR Introduction to the Teradata® RDBMS for UNIX® Version 2 Release 2.1 - NCR, 1998. - 315 p.
Download (direct link): inntroduktionteradata1998.pdf
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Transient journal management Contain information identifying the background management overhead associated with transient journal purging.
SCSI logical device driver Contain information identifying the following for external storage components connected through the SCSI buses (statistics are minimal): • Controller activities • Channel activities • Overhead activities
SCSI logical device Contain information identifying individual logical device activities for external storage components connected through the SCSI buses. Statistics are minimal.
Secondary cache Contain columns identifying the secondary cache miss rate.

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Introduction to the Teradata RDBMS for UNIX
Controlling the Collection and Logging of ResUsage Data

System Administration

Resource Usage

Column Type Description
Blocking cross reference Contain summary cross reference information derived from other columns. Includes data for all concurrency control and resource blocking occurring on the system.
Host controller Contain information identifying: • Traffic on host-to-node channels • Traffic on LANs • Overhead and management of the host channel and LANs
User controller Contain information identifying commands issued by users to the RDBMS and their progress.
Database object locking Contain information identifying both explicit and implicit lock requests held and waiting by a user on a database object.
Database object operations Contain information identifying mode (indexed or mass access) and kind (insert, update, etc.) of access to data rows.

Several mechanisms exist within the Teradata RDBMS for setting the collection and logging rates of ResUsage data. These control parameters can be set by the following means:

• xctl program

• Operator console

• Performance Monitor window

The control sets allow users to do any of the following:

• Enable or disable ResUsage table on a table by table basis

• Specify collection and logging periods

• Summarize the data or not.

You can use the statistics collected in DBC.ResUsage to analyze system bottlenecks, determining excessive swapping, and detecting system load imbalances

Collection rates control the frequency that ResUsage data is made available to applications.

Logging rates control the frequency that ResUsage data is logged to the ResUsage tables.

Introduction to the Teradata RDBMS for UNIX

12-17
System Administration

Resource Usage

There are two categories each of collection and logging rates.

This collection or logging rate . . . Controls the collection or logging of ResUsage data from . . .
vproc virtual processors.
node nodes.
You can set sampling intervals for all from 0 to 600 seconds, though extremely low rates are not recommended.

Collecting and logging ResUsage data incurs substantial overhead burden on the performance of the Teradata RDBMS. The shorter the logging period, the more burdensome this overhead becomes. Even collection without logging incurs overhead.

Note: A collection or logging rate of 0 disables ResUsage collection or logging (or both).

Use the DBW command SET LOG to establish the logging of resource utilization information. The system inserts one row of data into DBC.ResUsage for each sampling interval.

To produce a useful ResUsage macro report, the system imposes the Rules for Sampling following rules on logging and collection rates:

Intervals

The collection and logging rates that support a single ResUsage macro you want to run must both be greater than zero and either:

• Must be equal, or

• The logging rate must be an integer multiple of the collection rate.

For example,

IF you want to set this collection rate . . . TO this value . . . THEN this logging rate . . . Could be any of these values . . .
node 100 node • 100 • 200, 300, 400 3600
vproc 300 vproc • 300 • 600, 900, 1200 3600

The collection and logging rates that support multiple ResUsage macros:

• Must be equal, or

• The larger value must be an integer multiple of the smaller value.

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Introduction to the Teradata RDBMS for UNIX
For example,

System Administration

Resource Usage

IF you want to set this collection rate . . . TO this value . . . THEN this logging rate . . . Could be any of these values . . .
node 100 vproc • 100 • 200, 300, 400 3600 • 1, 2, 4, 5, 10 50
vproc 300 node • 300 • 600, 900, 1200 3600 • 1, 3, 5, 10, 12, ... , 150

If you enter collection or logging rates that do not comply with these rules, the system displays a diagnostic error message but does not update the rates to valid values.

You can specify either normal or summary modes for inserting ResUsage Collection information into ResUsage tables.

In this mode . . . This many rows are inserted per log period . . . Into this table . . .
Normal 1 row/node Spma
1 row/node-SCSI combination Sctl
1 row/vproc plus 1 row/node Svpr
1 row/vproc-client combination Shst
Summary 1 row/node Spma
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