Document revision date: 30 March 2001

Displays information about all transactions on the node or about a specified transaction.

Format

SHOW TRANSACTIONS [/qualifier[,...]]

Qualifiers

/DISPLAY=(item [,...])

Specifies the type of information to be displayed. The argument to /DISPLAY can be either a single item or a list. The following items can be specified.

Item	Description
ALL	All transaction control structures for the specified transaction. This is the default behavior.
BRANCHES	Control structures for branches of the specified transaction.
PARTICIPANTS	Control structures for resource managers participating in the specified transaction.
THREADS	Control structures for threads of the specified transaction.
TRANSACTIONS	Transaction control structures for the specified transaction.

/SUMMARY

Displays statistics for transactions on the node. The /SUMMARY qualifier cannot be used with the /TID or /DISPLAY qualifier.

/TID=tid

Specifies the transaction for which information is to be displayed. If you omit the /TID qualifier, the SHOW TRANSACTIONS command displays information about all transactions on the node.

Examples

SDA> SHOW TRANSACTIONS/TID=FAC21DE2-BA88-0092-8FA6-00000000B24B
 
      

The SHOW TRANSACTIONS command displays all the transaction control structure information for the transaction identified by the transaction identifier.

SDA> SHOW TRANSACTIONS/DISPLAY=(PARTICIPANTS, BRANCHES)
      

The SHOW TRANSACTIONS command displays the transaction branch and resource manager information for all transactions on the node.

Creates a subprocess of the process currently running SDA, copying the context of the current process to the subprocess and, optionally, executing within the subprocess a specified command.

Format

SPAWN [/qualifier[,...]] [command]

Parameter

command

Name of the command that you want executed by the subprocess.

Qualifiers

/INPUT=filespec

Specifies an input file containing one or more command strings to be executed by the spawned subprocess. If you specify a command string with an input file, the command string is processed before the commands in the input file. Once processing is complete, the subprocess is terminated.

/NOLOGICAL_NAMES

Specifies that the logical names of the parent process are not to be copied to the subprocess. The default behavior is that the logical names of the parent process are copied to the subprocess.

/NOSYMBOLS

Specifies that the DCL global and local symbols of the parent process are not to be passed to the subprocess. The default behavior is that these symbols are passed to the subprocess.

/NOTIFY

Specifies that a message is to be broadcast to SYS$OUTPUT when the subprocess completes processing or aborts. The default behavior is that such a message is not sent to SYS$OUTPUT.

When you use this qualifier, you must also specify the /NOWAIT qualifier.

/NOWAIT

Specifies that the system is not to wait until the subprocess is completed before allowing more commands to be specified. This qualifier allows you to specify new commands while the spawned subprocess is running. If you specify /NOWAIT, you should use /OUTPUT to direct the output of the subprocess to a file to prevent more than one process from simultaneously using your terminal.

The default behavior is that the system waits until the subprocess is completed before allowing more commands to be specified.

/OUTPUT=filespec

Specifies an output file to which the results of the SPAWN operation are written. You should specify an output other than SYS$OUTPUT whenever you specify /NOWAIT to prevent output from the spawned subprocess from being displayed while you are specifying new commands. If you omit the /OUTPUT qualifier, output is written to the current SYS$OUTPUT device.

/PROCESS=process-name

Specifies the name of the subprocess to be created. The default name of the subprocess is username_n, where username is the user name of the parent process.

Example

SDA>  SPAWN
$  MAIL
   .
   .
   .
$  DIR
   .
   .
   .
$  LO
   Process SYSTEM_1 logged out at 5-MAR-1993 15:42:23.59
SDA> 
      

This example uses the SPAWN command to create a subprocess that issues DCL commands to invoke the Mail utility. The subprocess then lists the contents of a directory before logging out to return to the parent process executing SDA.

Validates the integrity of the specified queue by checking the pointers in the queue.

Format

VALIDATE QUEUE [address] [/qualifier[,...]]

Parameter

address

Address of an element in a queue.

If you specify a period (.) as the address, SDA uses the last evaluated expression as the queue element's address.

If you do not specify an address, the VALIDATE QUEUE command determines the address from the last issued VALIDATE QUEUE command in the current SDA session.

If you do not specify an address, and no queue has previously been specified, SDA displays the following error message:

%SDA-E-NOQUEUE, no queue has been specified for validation

Qualifiers

/MAXIMUM_LINKS=nn

Specifies the number of entries in the queue that are to be validated.

/SELF_RELATIVE

Specifies that the selected queue is a self-relative queue.

Description

The VALIDATE QUEUE command uses the forward and backward pointers in each element of the queue to make sure that all such pointers are valid and that the integrity of the queue is intact. If the queue is intact, SDA displays the following message:

Queue is complete, total of n elements in the queue

In these messages, n represents the number of entries the VALIDATE QUEUE command has found in the queue.

If SDA discovers an error in the queue, it displays one of the following error messages:

Error in forward queue linkage at address nnnnnnnn after tracing x elements Error comparing backward link to previous structure address (nnnnnnnn) Error occurred in queue element at address oooooooo after tracing pppp elements

These messages can appear frequently when the VALIDATE QUEUE command is used within an SDA session that is analyzing a running system. In a running system, the composition of a queue can change while the command is tracing its links, thus producing an error message.

If there are no entries in the queue, SDA displays this message:

The queue is empty

Examples

SDA> VALIDATE QUEUE SCH$GQ_LEFWQ/MAXIMUM_LINKS=3
The queue is consistent through 3 elements
      

This example validates three elements in the SCH$GQ_LEFWQ queue.

SDA>  VALIDATE QUEUE/SELF_RELATIVE IOC$GL_IRPFL
Queue is complete, total of 159 elements in the queue
      

This example validates the self-relative queue that is the IRP pool list. The validation is successful and determines that there are 159 IRPs in the list.

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