Oracle Provider for OLE DB connection strings


Trusted Connection

This one specifies OS authentication to be used when connecting to an Oracle database.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;OSAuthent=1;

Oracle XE, VB6 ADO

Provider=OraOLEDB.Oracle;dbq=localhost:1521/XE;Database=myDataBase;User Id=myUsername;Password=myPassword;

Oracle XE, C++ ADO

Provider=OraOLEDB.Oracle;Data Source=localhost:1521/XE;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;

TNS-less connection string


Controling rowset cache mechanism

Specifies the type of caching used by the provider to store rowset data. OraOLEDB provides two caching mechanisms; File and Memory.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;CacheType=File;

Memory is the default value. All the rowset data is stored in-memory which provides better performance at the expense of higher memory utilization.

File = All the rowset data is stored on disk. This caching mechanism limits the memory consumption at the expense of performance.

Controling the fetchsize

This one specifies the number of rows the provider will fetch at a time (fetch array).

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;FetchSize=200;

The FetchSize value must be set appropriately depending on the data size and the response time of the network. If the value is set too high, this could result in more wait time during the execution of the query. If the value is set too low, this could result in many more round trips to the database. Valid values are 1 to 429,496,296. The default is 100.

Controling the chunksize

This one specifies the size, in bytes, of the data in LONG and LONG RAW columns fetched and stored in the provider cache.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;ChunkSize=200;

Providing a high value for this attribute improves performance, but requires more memory to store the data in the rowset. Valid values are 1 to 65535. The default is 100.

Using with Microsofts OLE DB .NET Data Provider

The Microsoft OLE DB .NET Data Provider can utilize OraOLEDB as the OLE DB Provider for accessing Oracle. However this must be enabled in the connection string.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;OLEDB.NET=True;

The OLEDB.NET connection string attribute must not be used in ADO applications.

Using OraOLEDB Custom Properties with Microsofts OLE DB .NET Data Provider

The SPPrmsLOB and NDatatype properties can only be set as connection string attributes when OraOLEDB is used by OLE DB .NET Data Provider.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;OLEDB.NET=True;SPPrmsLOB=False;NDatatype=False;SPPrmsLOB=False;

Using ADO, these properties would have been set as a property on the command. This is not possible if using the Microsofts OLE DB .NET Data Provider. So the properties are specified in the connection string instead.

PLSQLRSet: If the stored procedure, provided by the consumer, returns a rowset, PLSQLRSet must be set to TRUE (enabled).

NDatatype: This property allows the consumers to specify whether any of the parameters bound to the command are of Oracle's N datatypes (NCHAR, NVARCHAR or NCLOB). This information is required by OraOLEDB to detect and bind the parameters appropriately. This property should not be set for commands executing SELECT statements. However, this property must be set for all other SQLs such as INSERT, UPDATE, and DELETE.

SPPrmsLOB: This property allows the consumer to specify whether one or more of the parameters bound to the stored procedures are of Oracle's LOB datatype (CLOB, BLOB, or NCLOB). OraOLEDB requires this property to be set to TRUE, in order to fetch the parameter list of the stored procedure prior to execution. The use of this property limits the processing overhead to stored procedures having one or more LOB datatype parameters.

Using distributed transactions

This one specifies sessions to enlist in distributed transactions. This is the default behaviour.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;DistribTX=1;

Valid values are 0 (disabled) and 1 (enabled).