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Teradata RDBMS Database Administration - NCR

NCR Teradata RDBMS Database Administration - NCR , 2004. - 616 p.
Download (direct link): teradatadatabaseadmin2004.pdf
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The components that make up your Teradata RDBMS resource configuration

The tools provided for monitoring the state of those components

Teradata RDBMS Database Administration

A - 1 Appendix D: Tools for Monitoring Performance

Resource Components of Your Teradata RDBMS

Resource Components of Your Teradata RDBMS

The following components comprise your Teradata RDBMS configuration. The configuration is highly scalable; whether to expand by adding resources depends only on the requirements of your applications. (For guidelines on how to determine when and why to add resources, refer to "Solving Bottlenecks by Expanding Your Teradata RDBMS Configuration" on page 12-28.)


A processing unit with one or more CPUs.


Central processing unit. Teradata RDBMS nodes can have multiple CPUs. Be aware of the number of CPUs available to your server and know their speeds.


Access module vprocs. There is no direct relationship between the number of CPUs and the number of AMPs on a node. There is a direct relationship between the number of vdisks, or logical volumes, and the number of AMPs.

System Disks

The system disks store and execute the operating system, Teradata software, and applications. System disks are also used for dump and swap space. Be sure you have enough space to accommodate your applications.


A RAID LUN is a logical unit (slice) of a physical disk in a rank. A pdisk is a slice of a LUN. Pdisks are organized across ranks into virtual disks (vdisks) that are uniquely identified and independently addressable.


Each vdisk is assigned to a particular AMP. Virtual disks hold your data and all the system objects needed to manage your database, such as the transient and recovery journals and the data dictionary tables.

If your database is out of space, you can make room by deleting obsolete data, packing data tables, and defragmenting the cylinders. If you expect your data to grow, however, you need more vdisks. You can always add more disks; the suite of Teradata configuration utilities can configure vdisks, reconfigure AMPs and redistribute your data rows automatically.

D - 2 Teradata RDBMS Database Administration Appendix D: Tools for Monitoring Performance

Resource Components of Your Teradata RDBMS

LAN Connection

You must have a separate LAN connection for each logical LAN. Once connected to the server, a group of LAN PEs can service requests for all LANs. The defining limit is the number of sessions that can be handled by each Gateway, and the number of tpa nodes in your configuration.


Each tpa node can run one instance of the Teradata RDBMS Gateway. The Gateway has a limit of 1200 sessions per node. Be sure to balance PEs accordingly.

Channel Connection

You must have a separate channel connection for each individual channel (for example, VM gets one connection and MVS gets another.) You should also have multiple connections on each channel for redundancy. Typically, one PE is assigned to each channel connection.

Channel Driver

There is one Channel Driver per node. It has no session limit.


Parsing engine vprocs. Each PE can handle 120 sessions. Often, adding PEs per node can increase the number of concurrent sessions on your database. If you have enough PEs to handle each Gateway and channel, add another node.


Increased memory often improves performance for certain applications. Always increase memory if you increase the number of vprocs per node.


The BYNET is a combination of software and hardware that performs various types of communication functions among the nodes and vprocs on an MPP configuration.


The virtual BYNET, or vnet, performs communication functions among the vprocs running on a single node.

D - 2 Teradata RDBMS Database Administration

Appendix D: Tools for Monitoring Performance

Resource Check Tools

Resource Check Tools

The Resource Check Tools (RCT) feature is a suite of usage sampling tools and utilities designed to assist you and your NCR field support representative in:

Identifying a slow down or hang of the Teradata RDBMS. I Providing system statistics to help you determine the cause of the slow

down or hang.

Resource Check Tools comprise the following:

Tool Description References
dbschk utility Identifies if the RDBMS is hung or congested. By default, when the PDE reaches the TPA/TPA ready state, dbschk is started to run on the control node. It normally runs in batch mode. Results are written to a log file located in the temporary PDE directory (set by PDEPATH). If the temporary directory is not defined, then the /TMP directory is used for UNIX MP-RAS and C:\TEMP is used for Windows 2000. Can also be run interactively against a functional RDBMS. Writes only to STDOUT. Multiple instances can run simultaneously. (Note that results from all instances are logged to the same log file unless you specify a different filename to each instance.) "Troubleshooting a Slow or Hung Job" on page 12-23 "Resource Check Tools" in Teradata RDBMS Utilities From UNIX prompt: man utilityname From Windows 2000 DOS Command Prompt: pdehelp utilityname
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