Purpose
Sets the wait_across_crash (WAC) and tell_about_crash (TAC) options for handling node crashes.
Invocation
Executable.
Embedded SQL only.
Syntax
SET CRASH { WAIT_NOTELL | NOWAIT_TELL }
- WAIT_
- Specifies that WAC is to be set to Y and that TAC is to be set to N at runtime.
- NOWAIT_TELL
- Specifies that WAC is to be set to N and TAC is to be set to Y at runtime.
ANSI Compliance
SET CRASH is a Teradata extension to the ANSI/ISO SQL:2011 standard.
Authorization
None.
Usage
SET CRASH is enabled only for workstation-attached platforms. Mainframe precompilers generate an error if this statement is precompiled.
The crash options are in effect for all embedded SQL statements executed after SET CRASH is executed, including LOGON and CONNECT requests, until another SET CRASH is executed.
Preprocessor Behavior When a Node Resets
The following table describes the behavior of the preprocessor when a node resets:
| IF the Preprocessor is running on … | THEN it … |
|---|---|
| a resetting node | aborts. Preprocessing must be restarted after the node resets. This is equivalent to the situation where a utility or application is initiated on an external client that fails. |
any of the following:
|
reconnects its session (if connected to a Teradata Database) and the current SQL statement undergoing a syntax check returns an error. Restart preprocessing to ensure complete syntax checking. |
Application Behavior When a Node Resets
- The type of node on which the preprocessor is running
- The crash notification setting
If an embedded SQL application is running on a resetting node, then it aborts and must be restarted after the node resets.
This is equivalent to the situation where a utility or application is initiated on an external client that fails.
Application Behavior When SET CRASH = WAIT_NOTELL
- Non-resetting node
- Workstation-attached client
- Mainframe-attached client
The application reconnects its session and returns one of the following error codes from the Teradata Database; the embedded SQL application takes action appropriate to the error condition:
| Code | Description |
|---|---|
| Error 2825 | No record of the last request found after Teradata Database restart. |
| Error 2826 | Request completed but all output was lost due to Teradata Database restart. |
| Error 2828 | Request was rolled back during Teradata Database recovery. |
| Error 3120 | Request aborted because of a Teradata Database recovery. |
Application Behavior When SET CRASH = NOWAIT_TELL
- Non-resetting node
- Workstation-attached client
- Mainframe-attached client
is explained as follows:
The application immediately disconnects the session and the application receives one of the following CLI error codes:
| Code | Description |
|---|---|
| Error 219 (EM_DBC_CRASH_B) | Server connection lost (network or server problem). |
| Error 220 (EM_DBC_CRASH_A) |
An implicit CLI DISCONNECT request is issued to release any CLI resources tied to the crashed request and session. Any outstanding cursor and dynamic statement resources tied to the crashed session are also released.