Gateway and Vproc Limits - Teradata Database

Parameter

Value

Maximum number of sessions per PE.

120

Maximum number of gateways per node.

Multiple.

This is true because the gateway runs in its own vproc on each node. See Utilities for details.

The exact number depends on whether the gateways belong to different host groups and listen on different IP addresses.

Maximum number of sessions per gateway.

Tunable: 1 - 2,147,483,647.

1,200 maximum certified.

The default is 600.

See Utilities for details.

Maximum number of vprocs per system.

30,720

This includes the sum of all of the following types of vproc for a configuration:

Access Module Processor vprocs

Gateway Control vprocs

Parsing Engine vprocs

Relay Services Gateway vprocs

Teradata Virtual Storage allocator vprocs

Maximum number of AMP vprocs per system.

16,200

Maximum number of GTW vprocs per system.

This is a soft limit that Teradata technical support personnel can reconfigure for you.

Each GTW vproc on a node must be in a different host group. If two GTW vprocs are in the same host group, they must be on different nodes.

The default is one GTW vproc per node with all of them assigned to the same host group.

The maximum depends on:

Each gateway on a node must be assigned to a different host group from any other gateway on the same node and each gateway needs to be assigned a disjoint set of IP addresses to service.

This does not mean that all gateways in a system must be assigned to a different host group. It means that each gateway on the same node must be assigned to a different host group.

Gateways on different nodes can be assigned to the same host group.

Maximum number of PE vprocs per system.

This is a soft limit that Teradata technical support personnel can reconfigure for you.

2,048

Maximum number of TVS allocator vprocs per system.

This is a soft limit that Teradata technical support personnel can reconfigure for you.

2,048

Maximum number of vprocs, in any combination, per node.

127

Maximum number of AMP vprocs per cluster.

8

Maximum number of external routine protected mode platform tasks per PE or AMP.

This value is derived by subtracting 1 from the maximum total of PE and AMP vprocs per system (because each system must have at least one PE), which is 16,384. This is obviously not a practical configuration.

The valid range is 0 to 20, inclusive. The limit is 20 platform tasks for each platform type, not 20 combined for both. See Utilities for details.

20

Maximum number of external routine secure mode platform tasks per PE or AMP.

This value is derived by subtracting 1 from the maximum total of PE and AMP vprocs per system (because each system must have at least one PE), which is 16,384. This is obviously not a practical configuration.

20

Size of a request control block

~ 40 bytes

Default number of lock segments per AMP vproc.

This is controlled by the NumLokSegs parameter in DBS Control.

2

Maximum number of lock segments per AMP vproc.

This is controlled by the NumLokSegs parameter in DBS Control.

8

Default size of a lock segment.

This is controlled by the LockLogSegmentSize parameter in DBS Control.

64 KB

Maximum size of a lock segment.

This is controlled by the LockLogSegmentSize parameter in DBS Control.

1 MB

Default number of locks per AMP

3,200

Maximum number of locks per AMP.

209.000

Maximum size of the lock table per AMP.

The AMP lock table size is fixed at 2 MB and cannot be altered.

2 MB

Maximum size of the queue table FIFO runtime cache per PE.

Maximum number of SELECT AND CONSUME requests that can be in a delayed state per PE.

24

Amount of private disk swap space required per protected or secure mode server for C/C++ external routines per PE or AMP vproc.

256 KB

Amount of private disk swap space required per protected or secure mode server for Java external routines per node.

30 MB