This topic describes the parameters that are supported by SAP HANA Writer and how to configure SAP HANA Writer by using the codeless user interface (UI) and code editor.

Background information

SAP HANA Writer writes data to tables stored in SAP HANA databases. SAP HANA Writer connects to a remote SAP HANA database by using Java Database Connectivity (JDBC) and executes the INSERT INTO or REPLACE INTO statement to write data to the SAP HANA database. SAP HANA uses the InnoDB engine so that data is written to the database in batches.

SAP HANA Writer can also be used as a data migration tool by users such as database administrators. SAP HANA Writer obtains data from a reader and writes the data to the destination database based on the value of the writeMode parameter.
Note A synchronization node that uses SAP HANA Writer must have at least the permissions to execute the INSERT INTO or REPLACE INTO statement. Whether other permissions are required depends on the SQL statements that you specify in the preSql and postSql parameters when you configure the node.

Parameters

Parameter Description Required Default value
datasource The name of the data source. It must be the same as the name of the added data source. You can add data sources by using the code editor. Yes No default value
table The name of the table to which you want to write data. Yes No default value
column The names of the columns to which you want to write data. Separate the names with commas (,), such as "column": ["id", "name", "age"].

If you want to write data to all the columns in the destination table, set this parameter to an asterisk (*), such as "column":["*"].

Yes No default value
preSql The SQL statement that you want to execute before the synchronization node is run. You can execute only one SQL statement on the codeless UI and multiple SQL statements in the code editor. For example, you can set this parameter to the following SQL statement that is used to delete outdated data:
truncate table tablename
Note If you specify multiple SQL statements, whether all the statements can be successfully executed cannot be ensured.
No No default value
postSql The SQL statement that you want to execute after the synchronization node is run. You can execute only one SQL statement on the codeless UI and multiple SQL statements in the code editor. For example, you can set this parameter to the alter table tablenameadd colname timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP SQL statement that is used to add a timestamp. No No default value
batchSize The number of data records to write at a time. Set this parameter to an appropriate value based on your business requirements. This greatly reduces the interactions between Data Integration and SAP HANA and increases throughput. If you set this parameter to an excessively large value, an out of memory (OOM) error may occur during data synchronization. No 1024

Configure SAP HANA Writer by using the codeless UI

  1. Configure data sources.

    Configure Source and Target for the synchronization node.

    Configure data sources
    Parameter Description
    Connection The name of the data source to which you want to write data. This parameter is equivalent to the datasource parameter that is described in the preceding section.
    Table The name of the table to which you want to write data. This parameter is equivalent to the table parameter that is described in the preceding section.
    Pre sql The SQL statement that you want to execute before the synchronization node is run. This parameter is equivalent to the preSql parameter that is described in the preceding section.
    Post sql The SQL statement that you want to execute after the synchronization node is run. This parameter is equivalent to the postSql parameter that is described in the preceding section.
  2. Configure field mappings. This operation is equivalent to setting the column parameter that is described in the preceding section. Fields in the source on the left have a one-to-one mapping with fields in the destination on the right. Field mappings
    Operation Description
    Map Fields with the Same Name Click Map Fields with the Same Name to establish mappings between fields with the same name. The data types of the fields must match.
    Map Fields in the Same Line Click Map Fields in the Same Line to establish mappings between fields in the same row. The data types of the fields must match.
    Delete All Mappings Click Delete All Mappings to remove the mappings that are established.
    Auto Layout Click Auto Layout. Then, the system automatically sorts the fields based on specific rules.
  3. Configure channel control policies. Channel control
    Parameter Description
    Expected Maximum Concurrency The maximum number of parallel threads that the synchronization node uses to read data from the source or write data to the destination. You can configure the parallelism for the synchronization node on the codeless UI.
    Bandwidth Throttling Specifies whether to enable bandwidth throttling. You can enable bandwidth throttling and specify a maximum transmission rate to prevent heavy read workloads on the source. We recommend that you enable bandwidth throttling and set the maximum transmission rate to an appropriate value based on the configurations of the source.
    Dirty Data Records Allowed The maximum number of dirty data records allowed.
    Distributed Execution This parameter is not supported for synchronization nodes that use RestAPI Writer.

Configure SAP HANA Writer by using the code editor

In the following code, a synchronization node is configured to write data to an SAP HANA database:
{
    "type":"job",
    "version":"2.0",// The version number. 
    "steps":[
        {
            "stepType":"stream",
            "parameter":{},
            "name":"Reader",
            "category":"reader"
        },
        {
            "stepType":"saphana",// The writer type. 
            "parameter":{
                "postSql":[],// The SQL statement that you want to execute after the synchronization node is run. 
                "datasource":"",// The name of the data source. 
                "column":[// The names of the columns to which you want to write data. 
                    "id",
                    "value"
                ],
                "batchSize":1024,// The number of data records to write at a time. 
                "table":"",// The name of the table to which you want to write data. 
                "preSql":[
                     "delete from XXX;" // The SQL statement that you want to execute before the synchronization node is run. 
                   ]
            },
            "name":"Writer",
            "category":"writer"
        }
    ],
    "setting":{
        "errorLimit":{// The maximum number of dirty data records allowed. 
            "record":"0"
        },
        "speed":{
            "throttle":true,// Specifies whether to enable bandwidth throttling. The value false indicates that bandwidth throttling is disabled, and the value true indicates that bandwidth throttling is enabled. The mbps parameter takes effect only when the throttle parameter is set to true. 
            "concurrent":1, // The maximum number of parallel threads. 
            "mbps":"12"// The maximum transmission rate.
        }
    },
    "order":{
        "hops":[
            {
                "from":"Reader",
                "to":"Writer"
            }
        ]
    }
}