OpenAccess SDK SQL Engine core methods for .NET : Methods for .NET reference : dam_addLOBLocatorValToRow

dam_addLOBLocatorValToRow

This method is used to getting LOB data from the IP, based on a request from the client. The IP calls this method to add the locator value. When a client requests data, OpenAccess SQL Engine invokes dam_addLOBLocatorValToRow, which is then exported from the IP.

The IP layer can call this method to set a LOB locator value for the long data column specified by hCol in the row specified by hRow. Setting a LOB locator as the column value in the row allows the long data value for that column to be fetched in pieces. Fetching the long data in pieces can greatly reduce the amount of memory needed to process a query result because the entire long data value does not need to be held in memory.

int dam_addLOBLocatorValToRow(

int64 dam_hstmt,

int64 hRow,

int64 hCol,

int iXOType,

Object pColVal,

long lColValLen)

Table 90: Parameters for dam_addLOBLocatorValToRow
Parameter	Type	Description
IN
dam_hstmt	int64	The statement handle
hRow	int64	The row handle
hCol	int64	The column handle
iXOType	int	xo type of the stream.
pColVal	Object	LOB locator value, for example, File Handle.
IColValLen	long	The LOB locator value length.
RETURN
	int	DAM_SUCCESS – added the value to the row. DAM_FAILURE – error adding the value.