CHGDMTVAL - Set target system parameters

Use this command to set subscriber system parameters using the command line.

System parameters can also be set in Management Console. For more information about working with system parameters, see System parameters for IBM® CDC for Db2® for i

Applies To—Target

Parameters

Table 1. Supported keywords
Keyword	Description	Choices	Notes
NOTIFYQ	Message queue name	`Qualified object name`	Optional
	Qualifier 1: Message queue name	*SAME, `Name`
	Qualifier 2: Library	LIBL, `Name`, CURLIB, *SAME
NOTIFYCNT	Error count	*SAME, `Count`	Optional
AUTCDE	Authorization code	*SAME, `Code`	Optional
REFRESH	End on error	SAME, NO, *YES	Optional
MIRROR	End on error	SAME, NO, *YES	Optional
COLUMNVAL	Column value check	SAME, NO, *YES	Optional
NUMCOLMSG	Message generation format	SAME, NB, NO, YES	Optional
CMTCTRL	Commitment control	SAME, LEVEL1, *NONE	Optional
MSGNOTNULL	Message generation status	SAME, NO, *YES	Optional
DFTDATE	Date format	SAME, NEW, *OLD	Optional
MONSAMPFRQ	Latency metrics update frequency	5, `Time`	Optional
STARTUP	Wait time for initialization process termination	120, `Time`	Optional
PROGRESS	Progress message	0, `Time`	Optional
LCKTIMEOUT	Lock timeout	30, `Time`	Optional
RCDFMTCHK	Record format check	SAME, YES, *NO	Optional
DBPERCENT	Deadband percentage	3, `Number`	Optional
BKMKTRACE	Allow bookmark tracing	NO, YES	Optional

Message queue name (NOTIFYQ)

The name of the message queue where notifications are sent when the number of errors detected by CDC Replication exceeds the notify message threshold

Qualifier 1: Message queue name

Name: The name of the message queue.; The name of the library where the message queue resides must precede the name of the message queue.
*SAME: Keeps the present setting for this parameter.; This is the default setting.

Qualifier 2: Library

Name: The name of the library where the message queue resides.; The name of the library where the message queue resides must precede the name of the message queue.
*SAME: Keeps the present setting for this parameter.
*LIBL: Specifies the set of libraries in your library list. The libraries are searched in order for the first occurrence of the specified message queue.; This is the default setting.
*CURLIB: Specifies the current library.

Error count (NOTIFYCNT)

The number of errors that CDC Replication generates before a notification is sent to the notify message queue.

Count: The number of errors.; Minimum setting: 1 error; Maximum setting: 99999 errors
*SAME: Keeps the present setting for this parameter.; If a value smaller than the minimum setting is specified, the minimum setting is used.; If a value larger than the maximum setting is specified, the maximum setting is used.; This is the default setting.

Authorization code (AUTCDE)

The authorization code that is issued by IBM. Adjustments to the authorization code are required when moving from a temporary license to a permanent license, when machine classes have changed, or when upgrading CDC Replication to a new version.

Code: The authorization code.
*SAME: Keeps the present setting for this parameter.; This is the default setting.

End on error (REFRESH)

Specifies whether CDC Replication ends a data refresh when an error is encountered.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: Specifies that CDC Replication end a refresh immediately after it detects an error.; Unless you have a specific reason, you should set this parameter to *YES.
*NO: Specifies that CDC Replication report the error and continue the refresh after it detects the error.

End on error (MIRROR)

Specifies whether CDC Replication ends mirroring when an error is encountered.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: Specifies that CDC Replication end mirroring immediately after it detects an error.
*NO: Specifies that CDC Replication report the error and continue mirroring after it detects the error.; Unless you have a specific reason, you should set this parameter to *NO.

Column value check (COLUMNVAL)

Indicates whether CDC Replication should check decimal and numeric columns for valid formats before applying the numeric data to the target table.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: Indicates that you want the data in each packed and zoned field to be validated before it is applied to the target table.; If invalid packed/zoned data is found, a message is generated and the field is set to 0 automatically.
*NO: Indicates that you do not want the data in each packed and zoned field to be validated before it is applied to the target table.; If you are sure that numeric data does not have to be validated, set this parameter to *NO to maintain existing performance levels.

Message generation format (NUMCOLMSG)

Indicates how CDC Replication generates messages when it detects invalid numeric data. CDC Replication can convert invalid numeric data to zero on the subscription server.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: Specifies that a message be generated for each invalid numeric field detected.
*NO: Specifies that no messages be generated for each invalid numeric field detected.; If you are sure that numeric data does not have to be validated, set this parameter to *NO to maintain existing performance levels.
*NB: Specifies that no messages be sent when blank or uninitialized numeric fields are detected. Messages for other types of invalid numeric data are still generated.

Commitment control (CMTCTRL)

Specifies the level of commitment control for transaction processing.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*NONE: Turns off commitment control for transaction processing. No attempt to maintain transaction consistency is performed in the event that replication is interrupted.
*LEVEL1: Only committed transactions are received by the subscriber. The subscriber applies the transaction once the entire transaction is received from the publisher. In the event of a subscriber failure while the transaction is being applied, the transaction is re-sent and the apply is completed the next time replication is started.

If you select *LEVEL1, Refresh While Active on a publisher (see the CHGDMSVAL command) must be disabled.

Message generation status (MSGNOTNULL)

Indicates whether you want to generate the same message each time an attempt is made to replicate NULL to a target table column that is not NULL-capable.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: Generate a message each time NULL is replicated to a target table column that is not NULL-capable.
*NO: Do not generate a message each time NULL is replicated to a target table column that is not NULL-capable. For all instances, you are not notified by a message.

Date format (DFTDATE)

Specifies the date that is returned when an invalid date is passed to the %TODATE column manipulation function.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*NEW: Returns the date 1901-01-01.
*OLD: Returns the date 0001-01-01.

Latency metrics update frequency (MONSAMPFRQ)

The period of time, in seconds, between consecutive updates to a data store that is used to maintain replication latency metrics. The data store is referenced by Management Console to present replication latency information. This setting also represents how often the data store is sampled to determine whether or not latency has exceeded or is less than the specified threshold settings. Latency messages are generated when latency has exceeded or is less than the thresholds, and alerts can be configured in Management Console in response to a generated message.

If a value smaller than the minimum setting is specified, the minimum setting is used.

If a value larger than the maximum setting is specified, the maximum setting is used.

Time: Specifies the amount of time, in seconds.; Minimum setting: 0 seconds. If this parameter is set to 0, replication latency metrics are not updated in the data store.; Maximum setting: 3600 seconds (1 hour); Default setting: 5 seconds

Wait time for initialization process termination (STARTUP)

The maximum amount of time, in seconds, to wait before terminating the CDC Replication initialization phase. During CDC Replication initialization prior to data replication, process termination on the publication or subscription server can result in a suspension of the initialization phase.

This parameter allows you to set the maximum waiting period in this case.

If a value smaller than the minimum setting is specified, the minimum setting is used.

If a value larger than the maximum setting is specified, the maximum setting is used.

Time: Specifies the amount of time, in seconds.; Minimum setting: 4 seconds; Maximum setting: 3600 seconds (1 hour); Default setting: 120 seconds

Progress message (PROGRESS)

The amount of time, in seconds, to wait before generating the next progress message. Progress messages are placed in the event log.

If a value smaller than the minimum setting is specified, the minimum setting is used.

If a value larger than the maximum setting is specified, the maximum setting is used.

Time: Specifies the amount of time.; Maximum setting: 7200 seconds (2 hours); Minimum setting: 0 seconds. No progress messages are issued.; Default setting: 0 seconds. No progress messages are issued.

Lock timeout (LCKTIMEOUT)

The amount of time, in seconds, CDC Replication waits for a table or row to become unlocked before generating an error message in the event log.

If a value smaller than the minimum setting is specified, the minimum setting is used.

If a value larger than the maximum setting is specified, the maximum setting is used.

Time: Specifies the amount of time.; Minimum setting: 2 seconds; Maximum setting: 60 seconds; Default setting: 30 seconds

Record format check (RCDFMTCHK)

Indicates whether or not CDC Replication checks the record formats of the physical and logical files when the physical file is selected to receive mirrored data using a unique key.

*SAME: Keeps the present setting for this parameter.; This is the default setting.
*YES: CDC Replication checks the record formats of the physical and logical files. Only a physical file that has the same record format as the logical file can be selected as a destination of mirrored data using a unique key.
*NO: CDC Replication does not check the record formats of the physical and logical files. You can select a physical file to be the destination of mirrored data using a unique key that does not have the same record format as the logical file.

Deadband percentage (DBPERCENT)

The size of the range around each latency threshold setting.

Based on latency threshold settings defined in Management Console, a latency message is generated when latency has exceeded or is less than a threshold. Latency is calculated at regular intervals, where the interval is the current setting for the MONSAMPFRQ parameter. Alerts can be configured in Management Console in response to a generated message.

This parameter, which is expressed as a percentage, allows you to pad a threshold equally on both sides to create a range around the threshold. By adjusting this CDC Replication parameter, the size of the range around the threshold can be increased or decreased, and the threshold itself can be made thicker or thinner. A latency message is generated only when latency has exceeded the high limit of the range or is less than the lowest limit of the range. By changing the value assigned to this parameter, you can control the number of latency messages placed in the event log. For an example illustrating how this parameter can affect the number of latency messages that are generated, see the Deadband Percentage system parameter.

Since there are two latency threshold settings in Management Console (a warning threshold and a problem threshold), two separate ranges are defined when this parameter is set to a non-zero value. Each range is attached to its threshold, and so the two ranges can overlap with no change in behavior. If a value smaller than the minimum setting is specified, the minimum setting is used. If a value larger than the maximum setting is specified, the maximum setting is used.

Number: Specifies the size of the range.; Minimum setting: 3%; Maximum setting: 10%; Default setting: 3%

Allow bookmark tracing (BKMKTRACE)

Specifies whether or not to allow bookmark tracing.

*YES: Allows bookmark tracing.
*NO: Does not allow bookmark tracing.; This is the default setting.

Result

Output Relevant messages are produced to the job log.

Examples

CHGDMTVAL NOTIFYQ(NOTQLIB/NOTQ1)
NOTIFYCNT(10) AUTCDE(23456789) REFRESH(*YES) MIRROR(*YES) COLUMNVAL(*NO)
NUMCOLMSG(*NB) CMTCTRL(*NONE) MSGNOTNULL(*NO) DFTDATE(*NEW) MONSAMPFRQ(240)
STARTUP(60) PROGRESS(45) LCKTIMEOUT(10) RCDFMTCHK(*NO) DBPERCENT(10)

Notification messages are sent to message queue NOTQ1 located in library NOTQLIB.

CDC Replication detects up to 10 errors before sending a notification to the message queue.

The authorization code is 23456789.

Refresh or mirroring ends after CDC Replication encounters an error.

Data in each packed and zoned field is not validated before it is applied to the target table.

No messages are generated when blank or uninitialized numeric fields are detected.

Commitment control is disabled.

A message is not generated each time NULL is replicated to a target table column that is not NULL-capable.

The date that is returned when an invalid date is passed to the %TODATE column manipulation function is 1901-01-01.

Updates to the data store that is used to maintain replication latency metrics are made every 240 seconds.

The CDC Replication initialization phase terminates if it cannot be completed in 60 seconds.

Progress messages are generated every 45 seconds.

CDC Replication waits 10 seconds for a table or row to become unlocked before generating an error message in the event log.

The record formats of the physical and logical files are not checked. Physical files selected to be the destination of mirrored data using unique key can have different record formats as compared to the record formats of the logical files.

A 10% range is applied around each latency threshold setting.

Use

This command only applies to subscribers