Homogeneous replication
The following section describes how Qlik Talend Data Integration handles replication from Microsoft SQL Server (MS-CDC) to Microsoft SQL Server-based targets. Note that homogeneous replication is only relevant with Replication data projects.
In homogeneous replication, source column and table collations will be replicated to the target as described in Column and table collation.
- In homogeneous replication, the source data first passes through the Qlik Talend Data Integration data type and is therefore subject to any limitations of that type.
Data type exceptions
When replicating from Microsoft SQL Server (MS-CDC) to a supported SQL Server-based target, source and target data types are identical, with the following exceptions:
| Microsoft SQL Server (MS-CDC) Source | Microsoft SQL Server-based Target |
|---|---|
|
VARCHAR |
VARCHAR (x) (when x=0 or x>8000) else VARCHAR (max) |
|
NVARCHAR (length) |
NVARCHAR (x) (when x=0 or x>8000) else NVARCHAR (max) |
|
VARBINARY |
VARBINARY (x) (when x=0 or x>8000) else VARBINARY (max) |
|
HIERARCHYID |
VARCHAR (x) |
|
TIMESTAMP |
VARBINARY |
Column and table collation
When replicating from Microsoft SQL Server (MS-CDC) to an SQL Server-based target, column and table collations will be replicated to the target.
To support collation replication, the DBA must ensure that the collations defined for Microsoft SQL Server (MS-CDC) are the same as those defined for the SQL Server-based target.
Non-nullable columns and Primary/Unique Index names
Primary/Unique Index names are preserved during homogeneous replication. Non-nullable columns are also preserved during homogeneous replication, with the exception of the following data types:
- text
- ntext1
- varchar(max)
- nvarchar(max)
- varbinary(max)
- image
- xml