View and Set Parameters
A SharePlex Administrator (defined as a member of the SharePlex Admin group) can change parameters that are designated as user-configurable and is the only user authorized to do so.
View parameters
Use the list param command in sp_ctrl to view user-configurable SharePlex parameters. It displays parameter names, current settings, default values (if the parameter has been changed), and set-at points. The set-at point indicates when changes to a parameter will take effect. Possible set-at points are:
- Live means a change takes effect immediately.
- Restart Process means a change takes effect after the affected SharePlex process is restarted.
- Restart Cop means a change takes effect after sp_cop is restarted.
Additional options are available for viewing:
- All SharePlex parameters.
- Only parameters whose values have changed.
- Parameters relating to a specific SharePlex module.
To view descriptions of the SharePlex parameters, see theSharePlex Reference Guide.
Set parameters
Parameters can be set in the following ways:
-
With the set param command through the sp_ctrl interface. This is the preferred method because the new value remains intact no matter how many times replication stops and starts. The syntax is:
set param parameter_name value
Example:
- set param SP_OCT_REPLICATE_ALL_DDL 1
- As environment variables on Unix and Linux systems prior to starting sp_cop. The new value remains in effect only for that session of sp_cop.
Parameters for the Capture, Read, Export, Import, and Post processes can be set on a per-process basis when there are multiple instances of a process for an instance of SharePlex.
Set SharePlex parameters through sp_ctrl
The recommended way to change a SharePlex parameter is to use the set param command in sp_ctrl.
To restore a parameter’s setting to its default value, use the reset param command.
To view descriptions of the SharePlex commands, see theSharePlex Reference Guide.
Set SharePlex parameters as environment variables
On Unix and Linux, a SharePlex parameter can be set as an environment variable. The environment variable overrides the setting in the param-defaults files, but only for the session of sp_cop for which it was set. If you shut down sp_cop and restart it without resetting the environment variable, SharePlex uses the default setting in the param-defaults file.
To set a SharePlex parameter as an environment variable on Unix and Linux systems, use one of the following commands. Set the environment variable before starting sp_cop or, if sp_cop is running, restart sp_cop for the new setting to take effect.
ksh shell:
$ export parameter_name=value
csh shell:
$ setenv parameter_name value
Because of the temporary nature of environment variables, avoid using them if possible; instead make your changes with the set param command. When you rely on environment variables, especially when there are multiple users of SharePlex, you incur the risk of someone forgetting to set them (or using an incorrect value) when they restart sp_cop. That can have a significant, negative impact on replication and can result in the need to resynchronize the data.
The following files store SharePlex parameter settings:
-
The param-defaults file stores default settings that were set by developers for optimal replication performance under most conditions. The param-defaults file resides in the data sub-directory of the SharePlex product directory. The data in this file does not change unless a new version of SharePlex is installed.
Important: Never edit this file.
-
The paramdb file stores user-defined parameter settings — values that were changed from their defaults by a SharePlex Administrator using the set param command. Also stored in this file are the SharePlex Oracle user and the SharePlex user’s password.
When users execute the Reset Param command on sp_ctrl, the earlier entry stored in the paramdb gets removed.
The paramdb resides in the data sub-directory of the SharePlex variable-data directory. It starts out empty, and as SharePlex Administrators change parameter values, those values are added to it. User-defined parameter values override SharePlex default values when SharePlex is running. All of the settings in the paramdb file remain intact when a new version of SharePlex is installed.
Configure SharePlex to Replicate Data
SharePlex uses a configuration file to determine which tables to replicate and where to send the replicated data. This file also provides any special processing instructions, such as column mapping and data filtering. This chapter contains the information that you need to know in order to create a configuration file.
Once you understand the basics of how to create a configuration file and route data to your targets, you can move on to any of the more advanced configurations as needed. Documentation for those configurations is included in this guide.
Contents
Ensure Compatible Source-Target Mapping
The following guidelines help you ensure that the source and target objects that you want to map in a replication configuration are compatible.
Object names
For most replication strategies, the name and/or owner of a source object can be different from that of its target object. SharePlex replicates to the correct object because you specify it by owner and name within the configuration file. For high-availability configurations, the owner and name of a source table should be the same as the owner and name of the target table.
Source and target rows
Corresponding source and target rows must contain the same values to accurately reflect the source, unless transformation is being used.
One database in the configuration can have more or fewer rows than another database in the configuration. You can control which rows are replicated through horizontally partitioned replication. For more information, see Configure Horizontally Partitioned Replication.
Source and target columns
Corresponding source and target columns must:
A target table can have more columns than the source table.
- If the source and related target column names are identical, SharePlex will ignore the extra columns in the target table.
- If the source and target column names are not identical, SharePlex maps a one-to-one relationship in the order that the columns are defined in each table (for example, map the first column in the source to the first column in the target, map the second column to the second column, and so forth).
- To avoid Oracle errors if the extra (non-mapped) columns are NOT NULL, define default values for those columns. For more information, see Map Source and Target Columns.
A target table can have fewer columns than the number of columns in the source table, but you must use vertically partitioned replication to replicate only that subset of the source columns that matches the rows of the target. For more information, see Configure Vertically Partitioned Replication.
