ReadMode

Selects paged or streaming retrieval of SAP table data.

Possible Values

default, stream

Data Type

string

Default Value

"default"

Remarks

Select one of the following read modes:

default (default): Retrieves a complete table one page at a time, with an independent read for each page.
stream: Retrieves table data through one streaming read. SAP ERP sends subsequent batches through callbacks while the read remains in progress, and the driver adds rows to the result set as they arrive.

Streaming avoids repeating the read for each page and does not require the driver to hold the complete result in memory, which can reduce query execution time and memory consumption for large tables.

This connection property alone selects the read mode, including for incremental replication. With either mode, ReadTableFunction names the function module that the driver calls to read the data.

A connection reads through a single function module, so the module that ReadTableFunction resolves to serves every read on that connection, including metadata browsing and SELECT COUNT(*) queries.

Requirements

Before you set this connection property to stream, verify that your environment meets both of the following requirements.

The custom function module Z_STREAM_READ_TABLE is installed and activated on the SAP ERP system you connect to. The driver includes the source for this function module in the "db" subfolder of the installation directory. Because this module is installed by the customer, your SAP ERP administrator may have given it a name that follows your organization's conventions for custom function modules, such as ZCDATA_STREAM_READ_TABLE or a namespaced name like /CDATA/STREAM_READ_TABLE. Set ReadTableFunction explicitly to the installed name, even if it is Z_STREAM_READ_TABLE. When this property is set to stream, the driver validates that the configured function module exposes the CALLBACK_FM import parameter and rejects the function module if the parameter is missing.
The connection uses a supported RFC library. Streaming is supported with Classic, Classic_Unicode, NetWeaver, and JCo connections, but not with Soap.

If the connection uses the SAP Java Connector (JCo), also set CallBackProgramID and CallBackDestination. This requirement applies even when ConnectionType is set to Classic, Classic_Unicode, or NetWeaver in a Java-based deployment. See CallBackDestination for the SAP SM59 configuration requirements and restrictions on concurrent connections.