11.2 Teradata Parallel Transporter - Stream Operator- Additional Attributes

Attributes in Details:

Attributes	Required/Optional	Description
AppendErrorTable = ‘value’	O	Optional attribute that specifies whether or not the Stream Operator will use the existing error table. Valid values are: • ‘No’ = The Stream operator will not use the existing error table (default). • ‘Yes’ = The Stream operator will use the existing error table or create the error table if it does not exist. If the error table exists, the Stream operator displays the number of rows in the error table.   If the structure of the existing error table is not compatible with the error table that the Stream operator expects, the Stream operator terminates the job with an error message.   By default ,(ie when AppendErrorTable = 'NO'), the Stream operator terminates the job with an error message if the error table already exists.
ArraySupport = ‘option’	O	Optional attribute that specifies whether or not the Stream operator will use the ArraySupport feature for the job. Valid values are: • ‘On’ = The Stream operator will use ArraySupport for the entire job. • ‘Off’ = The Stream operator will not use ArraySupport. Even if the value for ArraySupport is not specified, Array Support is still enabled and the Stream operator will use it for the entire job if the following criteria are met:   • Both Teradata Database and CLIv2 support the Array Support feature. • The DML statement is a single DML statement or an atomic UPSERT statement. • The job step must have a single DML group if Serialize is On. If any of these criteria are not met, then the default value is 'Off' and the Stream operator will not use Array Support.   If the value for ArraySupport is set to ‘On’ and either Teradata Database or Teradata CLIv2 does not support the Array Support feature, the Stream operator will terminate with a fatal error. If the ARRAYSUPPORT DML option is used as part of the APPLY statement for a job, the DML value will override the value specified for the Stream operator ArraySupport attribute. Note that ArraySupport can be specified at two places : - 1) As an attribute 2) ARRAYSUPPORT DML operation.
Buffers = buffers	O	Optional attribute that specifies whether to increase the number of request buffers. The range of values is a lower limit of 2 and no upper limit. The default value is 3. The maximum number of request buffers that may be allocated is the number of buffers multiplied by the number of connected sessions (Buffers * connected_sessions). Request buffers are a global resource, so buffers are assigned to any session as needed, and then returned to a free pool. At any point in time, the number of request buffers assigned to a session can vary from zero to Buffers * connected_sessions.
DropErrorTable= 'value'	O	Optional attribute that specifies whether or not the Stream Operator will drop the error table at the end of a job. Valid values are: • ‘Yes’ = The Stream operator drops the error table when it is empty at the end of a job (default). Teradata PT automatically executes a DROP TABLE statement. • ‘No’ = The Stream operator will not drop the error table even if it is empty at the end of a job. If the error table is not dropped, it can be used when AppendErrorTable is set to ‘Yes’ at the beginning of the next job.
DropMacro = 'value'	O	Optional attribute that instructs the Stream operator whether to drop macros or keep them for future use. VARCHAR DropMacro = '<Y[es]|N[o]>' By default, the Streamoperator drops macros at the end of a successful job. When the value of DropMacro is N or No, the macros remain in the Teradata Database until a DROP MACRO statement is issued against them.
ErrorLimit = limit	O	Optional attribute that Teradata Database specifies the approximate number of records that can be stored in the error table before the Stream operator job is terminated. This number is approximate because the Stream operator sends multiple rows of data at a time to Teradata Database. By the time Teradata PT processes the message indicating that the error limit has been exceeded, it may have loaded more records into the error table than the actual number specified in the error limit. The ErrorLimit specification must be greater than 0. Specifying an invalid value will cause the Stream operator job to terminate. By default, the ErrorLimit value is unlimited.
ErrorTable = 'etname'	O	Optional attribute that specifies the name of the error table. This table contains information concerning data conversion errors, constraint violations, and other error conditions. If the database for the error table is not specified, the table is placed in the database associated with the user logon. By default, the error table must be a new table. This default can be changed. If the AppendErrorTable attribute is set to 'Yes' or 'Y', then the error table can be a new or existing table. If the name is not supplied, it is created by the Stream Operator. User-supplied names for error tables must not exceed 30 bytes
LogTable = 'ltname'	R	Required attribute that specifies the name of the restart log table for checkpoint information. If the restart log table does not exist, the Stream operator creates it. If it exists, the Stream operator restarts from the last checkpoint. The following privileges are required on the restart log table: • SELECT • INSERT • DELETE The following privileges are required on the database that contains the restart log table. • DROP • CREATE The Stream operator automatically maintains the restart log table. Manipulating the restart log table in any way invalidates the restart capability. If the restart log table name is not fully qualified, it is created under the user’s default (logon) database. Otherwise, you may specify a working database using the WorkingDatabase attribute.
MacroDatabase = 'dbname'	O	Optional attribute that specifies the database to contain any macros used by the Stream operator. The default macro database is the restart log table database.
MaxSessions = maxsessions	O	Optional attribute that specifies the maximum number of sessions to log on. The MaxSessions value must be greater than 0. Specifying a value less than 1 terminates the job. The default is one session for each operator instance. (note this is different that export,load ,update operator) The sessions are distributed across instances. The main instance calculates an even distribution of the Stream operator sessions among the number of instances. For example, if there are 4 instances and 16 Stream operatorsessions, then each instance will log on 4 Stream operator sessions.
MinSessions = minsessions	O	Optional attribute that specifies the minimum number of sessions required for the Stream operator job to continue. The MinSessions value must be greater than 0 and less than or equal to the maximum number of Stream operator sessions. Specifying a value less than 1 terminates the job. The default is 1
OperatorCommandID =‘commandID’	O	Although you can specify rate and periodicity values using Stream operator attributes, you may not know the optimal values for a specific job step until after the job has begun running. OperatorCommandId allows you to identify a specific reference of a Stream operator to which you can assign new rate or periodicity values after the job has begun, using twbcmd: Teradata PT will generate a default value for operatorCommandId composed of <operator object name> + <process Id> for each copy of the operator in the APPLY specification. If you want to assign another identifier, do the following: 1 Declare the operatorCommandId attribute in the DEFINE OPERATOR statement for the STream operator. 2 You can optionally assign a value to the OperatorCommandID attribute in a referenced copy of the Stream operator (in an APPLY statement). If no value is assigned, Te r a d a t a P Twill provide a system-generated value. A useful operatorCommandID value might be the number of the job step in which you want to change the Rate, as follows: APPLY <dml1> TO OPERATOR ( Stream_Oper[2] ATTRIBUTES ( OperatorCommandID = ‘ratestep#1’)), APPLY <dml2> TO OPERATOR ( Stream_Oper[3] ATTRIBUTES ( OperatorCommandID = ‘ratestep#2’)), 3 Use the twbcmdutility to assign a Rate value to a specific Stream operator copy.
Pack = number	O	Optional attribute that specifies the number of statements to pack into a multiple statement request. The maximum value is 2400. The default value is 20.
PackMaximum = 'packmax'	O	Optional attribute that requests the Stream operator to dynamically determine the maximum possible pack factor for the current Stream job. The PackMaximum values are: • 'No' ('N') = No pack (default) • 'Yes' ('Y') = Determine maximum possible pack factor
Periodicity = periodicity	O	Option that specifies that the DML statements sent by the Stream operator to the Teradata Database will be as evenly distributed as possible over each one minute interval. The periodicity value sets the number of sub-intervals per minute. Periodicity facilitates the orderly and efficient use of system resources. For example: If the statement rate is 1600 and the periodicity value is 10, then the maximum number of statements processed is 160 (1600/ 10) statements every 6 (60/10) seconds. Use of the Periodicity attribute is subject to the following conditions and rules: • The valid values are integers between 1 and 600. • The default value is 4, which means four 15-second periods per minute. • If the statement rate is unlimited, then the Periodicity value is ignored.  So this attribute is related to the Rate attribute. • While the job is running, users can change the Periodicity value using the Teradata PT External command interface utility twbcmd.
QueueErrorTable = ‘option’	O	Optional attribute that specifies whether the error table is a queue table. Valid values are: • ‘Yes’ (‘Y’) = Create the error table as a queue table. • ‘No’ (‘N’) = (Default) Create the error table as a non-queue table. This attribute is unique to the Stream operator and to the error table in the Stream operator. This attribute is especially useful in capturing errors that result when using the SELECT and CONSUME database operation, which returns rows and DELETEs them. Using an error table as a queue table can eliminate the need to delete the rows in the error table.
Rate = statement rate	O	Option that specifies the maximum number of DML statements per minute the Stream operator can submit to the Teradata Database. Use of the Rate attribute is subject to the following conditions and rules: • The statement rate must be a positive integer. • If the statement rate is not specified, the rate is unlimited. • If the statement rate is less than the statement packing factor, the Stream operator sends requests smaller than the packing factor. • If the statement rate is invalid, Stream Operator will display an error message and terminate with a return code of 8. • While the job is running, users can change the statement rate value using the Teradata PT External command interface utility twbcmd.
Robust = 'robust'	O	Optional attribute that specifies whether or not to use robust restart logic for recovery/restart operations. In “robust mode,” one database row is written in the log restart table for every request issued.(1 for each multistatement request.. So letter entries with higher pack attribute) This collection of rows in the restart log table can be referred to as the request log. Because a request is guaranteed by the Teradata Database to either completely finish or completely roll back, the request log will always accurately reflect the completion status of an import. The Robust values are: • 'Yes' ('Y') = Use robust restart logic (default). In the robust mode, for each packed request, a number of “partial checkpoint” rows are written to the log between checkpoints. The rows are deleted each time a checkpoint is written. In Robust recovery mode, the Stream operator must next ascertain how much processing has been completed since the last logged checkpoint. This is accomplished by reading back a set of “Partial Checkpoints” from the Teradata Database, sorting them and then reprocessing all transactions that were left incomplete when the job was interrupted. • 'No' ('N') = Use simple restart logic. In this case, restarts cause the Stream operator to begin where the last checkpoint occurs in the job. Any processing that occurs after the checkpoint is redone. (note that by default checkpoint is taken before and after the data is sent ) This method does not have the extra overhead of the additional database writes in the robust logic, and should be adequate in certain DML statements that can be repeated without changing the results of the operation.
TenacityHours = hours	O	Optional attribute that specifies the number of hours that the Stream operator continues trying to log on when the maximum number of sessions are already running on the Teradata Database. The default value is 4 hours. To enable the tenacity feature, the hours value must be greater than 0. Specifying a value of 0 disables the tenacity feature. Specifying a value of less than 0 terminates the Stream operator job
TenacitySleep = minutes	O	Optional attribute that specifies the number of minutes that the Stream operator job pauses before retrying a log on operation when the maximum number of sessions are already running on the Teradata Database. The minutes value must be greater than 0. If you specify a value less than 1, the Stream operator responds with an error message and terminates the job. The default is 6 minutes.
WorkingDatabase = 'dbname'	O	Optional attribute that specifies a database other than the logon database as the default database. The name of the database that is specified with this attribute is used in the Teradata SQL DATABASE statement that is sent by the operator immediately after connecting the two SQL sessions.
UserName = 'userid'	R	Same as in Export operator.
UserPassword = 'password'	R	Same as in Export operator.
TraceLevel = 'level'	O	Same as in Export operator.
QueryBandSessInfo = ‘<Query Band expression>’	O	Same as in Export operator.
LogonMech = ‘string’	O	Same as in Export operator.
LogonMechData = ‘data’	O	Same as in Export operator.
LogSQL = 'option'	O	Same as in Export operator.
DataEncryption = ‘option’	O	Same as in Export operator.
DateForm = 'datatype'	O	Same as in Export operator.
AccountId = 'acctid'	O	Optional attribute that specifies the account associated with the user name. If omitted, it defaults to the account identifier of the immediate owner database.
NotifyExit = 'inmodname'	O	Attribute that specifies the name of the user-defined notify exit routine with an entry point named _dynamn. If no value is supplied, the following default name is used: • libnotfyext.dllfor Windows platforms • libnotfyext.slfor HP-UX platforms • libnotfyext.sofor all other UNIX platforms • NOTFYEXTfor z/OS platforms
NotifyLevel = 'notifylevel'	O	Optional attribute that specifies the level at which certain events are reported. The valid values are: • 'Off' = no notification of events is provided (default) • 'Low' = 'Yes' in the Low Notification Level column • 'Med' = 'Yes' in the Medium Notification Level column • 'High' = 'Yes' in the High Notification Level column • “Ultra’ = ‘Yes” in the Ultra Notification Level column
NotifyMethod = 'notifymethod'	O	Optional attribute that specifies the method for reporting events. The methods are: • 'None'= no event logging is done (default). • 'Msg'= sends the events to a log. • On Windows, the events are sent to the event log that can be viewed using the Event Viewer. The messages are sent to the Application log. • On Solaris, AIX, Linux, and HP-UX platforms, the destination of the events is dependent upon the setting specified in the /etc/syslog.conffile. • On z/OS systems, events are sent to the job log. • 'Exit'= sends the events to a user-defined notify exit routine.
NotifyString = 'notifystring'	O	Optional attribute that provides a user-defined string to precede all messages sent to the system log. This string is also sent to the userdefined notify exit routine. The maximum length of the string is: • 80 bytes, if the NotifyMethod is 'Exit' • 16 bytes, if NotifyMethod is 'Msg'