SharePlex 11.3 - Installation and Setup Guide

Define a Unique Key

Define a Unique Key

If a table was not created with a primary or unique key, you can specify columns to use as a key when you specify the object in the configuration file. SharePlex uses the specified columns as a unique key in its WHERE clause to locate target rows for posting.

Define a unique key - Oracle to Oracle

The columns that you specify as a key must meet the following criteria:

• They cannot be LONG or LOB columns.
• They must be able to uniquely identify a row. Otherwise, replication could return out-of-sync errors or post to incorrect target rows.
• They must be part of the column partition if the table is configured for vertically partitioned replication. When using the exclude column notation in vertical partitioning, the excluded columns cannot be used in the key definition. For more information, see Configure Partitioned Replication.
• Include the columns in a supplemental log group. Otherwise, SharePlex must query the database for their values.
• Create an index on the target table and add the index to the SharePlex hints file, located in the variable-data directory, which directs the Post process to use the index.

Syntax for key definition

To create a key definition, type a space after the source object and use the following syntax, including the parentheses.

src_owner.table !key (column_list)

where:

• !key is a required keyword.
• column_list is a list of columns to include in the key. Separate column names with commas. A space after the comma is optional.

Example

Datasource:o.ora1
scott.tab !key(name,ID)    scott.tab2    sysB@oraB

Define a unique key - PostgreSQL to PostgreSQL

The columns that you specify as a key must meet the following criteria:

• A unique key cannot be TEXT, BYTEA, CHAR with more than 2000 characters, VARCHAR without size or more than 4000 characters.

• They must be able to uniquely identify a row. Otherwise, replication could return out-of-sync errors or post to incorrect target rows.

• They must be part of the column partition if the table is configured for vertically partitioned replication. When using the exclude column notation in vertical partitioning, the excluded columns cannot be used in the key definition. For more information, see Configure Partitioned Replication.

• Create an index on the target table, it directs the Post process to use the index.

Syntax for key definition

To create a key definition, type a space after the source object and use the following syntax, including the parentheses.

src_schema.table !key (column_list)

where:

• !key is a required keyword.
• column_list is a list of columns to include in the key. Separate column names with commas. A space after the comma is optional.

Example

Datasource:r.dbname
scott.tab !key(name,ID)    scott.tab2    sysB@dbname

Define a unique key - PostgreSQL to Oracle

The columns that you specify as a key must meet the following criteria:

• A unique key cannot be text, char with more than 2000 characters, varchar without size or more than 4000 characters.

• They must be able to uniquely identify a row. Otherwise, replication could return out-of-sync errors or post to incorrect target rows.
• They must be part of the column partition if the table is configured for vertically partitioned replication. When using the exclude column notation in vertical partitioning, the excluded columns cannot be used in the key definition. For more information, see Configure Partitioned Replication.
• Create an index on the target table and add the index to the SharePlex hints file, located in the variable-data directory, which directs the Post process to use the index.

Syntax for key definition

To create a key definition, type a space after the source object and use the following syntax, including the parentheses.

src_schema.table !key (column_list)

where:

• !key is a required keyword.
• column_list is a list of columns to include in the key. Separate column names with commas. A space after the comma is optional.

Example

Datasource:r.dbname
"scott"."tab" !key(name,ID)    "scott"."tab2"    sysB@o.oraB