Interview Q & A for Oracle Golden Gate Part - 5

83. Summary of Manager Commands

Use the Manager commands to control the Manager process. Manager is the parent process of Oracle GoldenGate and is responsible for the management of its processes and files,

resources, user interface, and the reporting of thresholds and errors.

Command	Description
INFO MANAGER	Returns information about the Manager port and child processes.
SEND MANAGER	Returns information about a running Manager process.
START MANAGER	Starts the Manager process.
STATUS MANAGER	Returns the state of the Manager process.
STOP MANAGER	Stops the Manager process.

84. Summary of Extract Commands

Use the Extract commands to create and manage Extract groups. The Extract process captures either full data records or transactional data changes, depending on configuration parameters,

and then sends the data to a trail for further processing by a downstream process, such as a data-pump Extract or the Replicat process.

Command	Description
ADD EXTRACT	Creates an Extract group.
ALTER EXTRACT	Changes attributes of an Extract group
CLEANUP EXTRACT	Deletes run history for an Extract group
DELETE EXTRACT	Deletes an Extract group.
INFO EXTRACT	Returns information about an Extract group.
KILL EXTRACT	Forcibly terminates the run of an Extract group.
LAG EXTRACT	Returns information about Extract lag.
REGISTER EXTRACT	Registers an Extract group with an Oracle database.
SEND EXTRACT	Sends instructions to, or returns information about, a running Extract group.
START EXTRACT	Starts an Extract group.
STATS EXTRACT	Returns processing statistics for an Extract group.
STATUS EXTRACT	Returns the state of an Extract group.
STOP EXTRACT	Stops an Extract group.
UNREGISTER EXTRACT	Unregisters an Extract group from an Oracle database.

85. Summary of Replicat Commands

Use the Replicat commands to create and manage Replicat groups. The Replicat process reads data extracted by the Extract process and applies it to target tables or prepares it for use by another application, such as a load application.

Command	Description
ADD REPLICAT	Adds a Replicat group.
ALTER REPLICAT	Changes attributes of a Replicat group.
CLEANUP REPLICAT	Deletes run history of a Replicat group.
DELETE REPLICAT	Deletes a Replicat group.
INFO REPLICAT	Returns information about a Replicat group.
KILL REPLICAT	Forcibly terminates a Replicat group.
LAG REPLICAT	Returns information about Replicat lag.
REGISTER REPLICAT	Registers a Replicat group with an Oracle database.
SEND REPLICAT	Sends instructions to, or returns information about, a running Replicat group.
START REPLICAT	Starts a Replicat group.
STATS REPLICAT	Returns processing statistics for a Replicat group.
STATUS REPLICAT	Returns the state of a Replicat group.
STOP REPLICAT	Stops a Replicat group.
SYNCHRONIZE REPLICAT	Returns all threads of a coordinated Replicat to a uniform start point after an unclean shutdown of the Replicat process.
UNREGISTER REPLICAT	Unregisters a Replicat group from an Oracle database.

86. Summary of the ER Command

Use the ER command to issue standard Extract and Replicat commands to multiple Extract and Replicat groups as a unit.

Command	Description
INFO ER *	Returns information about the specified wildcarded groups.
KILL ER *	Forcibly terminates the specified wildcarded groups.
LAG ER *	Returns lag information about the specified wildcarded groups.
SEND ER *	Sends instructions to, or returns information about, the specified wildcarded groups.
START ER *	Starts the specified wildcarded groups.
STATS ER *	Returns processing statistics for the specified wildcarded groups.
STATUS ER*	Returns the state of the specified wildcarded groups.
STOP ER *	Stops the specified wildcarded groups.

87. Summary of Trail Commands

Use the trail commands to create and manage Oracle GoldenGate trails. A trail is a series of files in which Oracle GoldenGate temporarily stores extracted data on disk until it has been applied to the target location.

Command	Description
ADD EXTTRAIL	Adds a local trail to the Oracle GoldenGate configuration.
ADD RMTTRAIL	Adds a remote trail to the Oracle GoldenGate configuration.
ALTER EXTTRAIL	Changes attributes of a local trail.
ALTER RMTTRAIL	Changes attributes of a remote trail.
DELETE EXTTRAIL	Removes a local trail from the Oracle GoldenGate configuration.
DELETE RMTTRAIL	Removes a remote trail from the Oracle GoldenGate configuration.
INFO EXTTRAIL	Returns information about a local trail.
INFO RMTTRAIL	Returns information about a remote trail.

88. Summary of Parameter Commands

Use the parameter commands to view and manage Oracle GoldenGate parameter files.

Command	Description
EDIT PARAMS	Opens a parameter file for editing in the default text editor.
SET EDITOR	Sets the default text editor program for editing parameter files.
VIEW PARAMS	Displays the contents of a parameter file in read-only mode on-screen.

89. Summary of Database Commands

Use the database commands to interact with the database from GGSCI.

Command	Description
DBLOGIN	Logs the GGSCI session into a database so that other commands that affect the database can be issued.
DUMPDDL	Shows the data in the Oracle GoldenGate DDL history table.
ENCRYPT PASSWORD	Encrypts a database login password.
FLUSH SEQUENCE	Updates an Oracle sequence so that initial redo records are available at the time that Extract starts capturing transaction data after the instantiation of the replication environment.
LIST TABLES	Lists the tables in the database with names that match the input specification.
MININGDBLOGIN	Specifies the credentials of the user that an Oracle GoldenGate process uses to log into an Oracle mining database.
SET NAMECCSID	Sets the CCSID of the GGSCI session in a DB2 for i environment.

90. Summary of Trandata Commands

Use trandata commands to configure the appropriate database components to provide the transaction information that Oracle GoldenGate needs to replicate source data operations.

Command	Description
ADD SCHEMATRANDATA	Enables schema-level supplemental logging.
ADD TRANDATA	Enables table-level supplemental logging.
DELETE SCHEMATRANDATA	Disables schema-level supplemental logging.
DELETE TRANDATA	Disables table-level supplemental logging.
INFO SCHEMATRANDATA	Returns information about the state of schema-level supplemental logging.
INFO TRANDATA	Returns information about the state of table-level supplemental logging.

91. Summary of Checkpoint Table Commands

Use the checkpoint table commands to manage the checkpoint table that is used by Oracle GoldenGate to track the current position of Replicat in the trail.

Command	Description
ADD CHECKPOINTTABLE	Creates a checkpoint table in a database.
CLEANUP CHECKPOINTTABLE	Removes checkpoint records that are no longer needed.
DELETE CHECKPOINTTABLE	Removes a checkpoint table from a database.
INFO CHECKPOINTTABLE	Returns information about a checkpoint table.
UPGRADE CHECKPOINTTABLE	Adds a supplemental checkpoint table when upgrading Oracle GoldenGate from version 11.2.1.0.0 or earlier.

92. Summary of Oracle Trace Table Commands

Use the trace table commands to manage the Oracle GoldenGate trace table that is used with bidirectional synchronization of Oracle databases. Replicat generates an operation in the trace table at the start of each transaction. Extract ignores all transactions that begin with an operation to the trace table. Ignoring Replicat's operations prevents data from looping back and forth between the source and target tables.

Command	Description
ADD TRACETABLE	Creates a trace table.
DELETE TRACETABLE	Removes a trace table.
INFO TRACETABLE	Returns information about a trace table.

93. Summary of Oracle GoldenGate Data Store Commands

Use the data store commands to control the data store that Oracle GoldenGate uses to store monitoring information for use by Oracle GoldenGate Monitor.

Command	Description
ALTER DATASTORE	Changes the memory model that is used for interprocess communication by the data store.
CREATE DATASTORE	Creates the data store.
DELETE DATASTORE	Removes the data store.
INFO DATASTORE	Returns information about the data store.
REPAIR DATASTORE	Repairs the data store after an upgrade or if it is corrupt.

94. Summary of Miscellaneous Oracle GoldenGate Commands

Use the following commands to control various other aspects of Oracle GoldenGate.

Command	Description
!	Executes a previous GGSCI command without modifications.
ALLOWNESTED | NOALLOWNESTED	Enables or disables the use of nested OBEY files.
CREATE SUBDIRS	Creates the default directories within the Oracle GoldenGate home directory.
DEFAULTJOURNAL	Sets a default journal for multiple tables or files for the ADD TRANDATA command when used for a DB2 for i database.
FC	Allows the modification and re-execution of a previously issued GGSCI command.
HELP	Provides assistance with syntax and usage of GGSCI commands.
HISTORY	Shows a list of the most recently issued commands since the startup of the GGSCI session.
INFO ALL	Displays status and lag for all Oracle GoldenGate processes on a system.
INFO MARKER	Displays recently processed markers from a NonStop system.
OBEY	Processes a file that contains a list of Oracle GoldenGate commands.
SHELL	Executes shell commands from within the GGSCI interface.
SHOW	Displays the attributes of the Oracle GoldenGate environment.
VERSIONS	Displays information about the operating system and database.
VIEW GGSEVT	Displays the Oracle GoldenGate error log (ggserr.log file).
VIEW REPORT	Displays the process report or the discard file that is generated by Extract or Replicat.

95. Integrated Capture (IC)

• In the Integrated Capture mode, GoldenGate works directly with the database log mining server to receive the data changes in the form of logical change records (LCRs).
• IC mode does not require any special setup for the databases using ASM, transparent data encryption, or Oracle RAC.
• This feature is only available for oracle databases in Version 11.2.0.3 or higher.
•  It also supports various object types which were previously not supported by Classic Capture.
• This Capture mode supports extracting data from source databases using compression.
• Integrated Capture can be configured in an online or downstream mode.

96. Why is Supplemental logging required for Replication?

When a transaction is committed on the source database, only new data is written to the Redo log. However, for Oracle to apply these transactions on the destination database, the before image key values are required to identify the effected rows. This data is also placed in the trail file and used to identify the rows on the destination, using the key value the transactions are executed against them.

97. List important considerations for bi-directional replication?

The customer should consider the following points in an active-active replication environment.

• Primary Key: Helps to identify conflicts and Resolve them.
• Sequences: Are not supported. The work around is use to use odd/even, range or concatenate sequences.
• Triggers: These should be disabled or suppressed to avoid using uniqueness issue
• Data Looping: This can easy avoided using OGG itself
• LAG: This should be minimized. If a customer says that there will not be any LAG due to network or huge load, then we don’t need to deploy CRDs. But this is not the case always as there would be some LAG and these can cause Conflicts.
• CDR (Conflict Detection & Resolution): OGG has built in CDRs for all kind of DMLs that can be used to detect and resolve them.
• Packaged Application: These are not supported as it may contain data types which are not support by OGG or it might not allow the application modification to work with OGG.

98. Are OGG binaries supported on ASM Cluster File System (ACFS)?

Yes, you can install and configure OGG on ACFS.

99. Are OGG binaries supported on the Database File System (DBFS)? What files can be stored in DBFS?

No, OGG binaries are not supported on DBFS. You can however store parameter files, data files (trail files), and checkpoint files on DBFS.

100. What is the default location of the GLOBALS file?

A GLOBALS file is located under Oracle GoldenGate installation directory (OGG HOME)

101. Where can filtering of data for a column be configured?

Filtering of the columns of a table can be set at the Extract, Pump or Replicat level.

102. Is it a requirement to configure a PUMP extract process in OGG replication?

A PUMP extract is an option, but it is highly recommended to use this to safe guard against network failures. Normally it is configured when you are setting up OGG replication across the network.