Oracle.DataAccess.dll assembly provides two namespaces:

• The Oracle.DataAccess.Client namespace contains ODP.NET classes and enumerations.
• The Oracle.DataAccess.Types namespace contains the Oracle Data Provider for .NET Types (ODP.NET Types).

Oracle.DataAccess.Client Classes

1. OracleCommand - An OracleCommand object represents a SQL command, a stored procedure, or a table name
2. OracleCommandBuilder - An OracleCommandBuilder object provides automatic SQL generation for the OracleDataAdapter when updates are made to the database
3. OracleConnection - An OracleConnection object represents a connection to an Oracle database
4. OracleDataAdapter - An OracleDataAdapter object represents a data provider object that communicates with the DataSet
5. OracleDataReader - An OracleDataReader object represents a forward-only, read-only, in-memory result set
6. OracleError - The OracleError object represents an error reported by an Oracle database
7. OracleErrorCollection - An OracleErrorCollection object represents a collection of OracleErrors
8. OracleException - The OracleException object represents an exception that is thrown when Oracle Data Provider for .NET encounters an error
9. OracleFailoverEventArgs - The OracleFailoverEventArgs object provides event data for the OracleConnection.Failover event
10. OracleFailoverEventHandler delegate - The OracleFailoverEventHandler delegate represents the signature of the method that handles the OracleConnection.Failover event
11. OracleGlobalization - The OracleGlobalization class is used to obtain and set the Oracle globalization settings of the session, thread, and local computer (read-only)
12. OracleInfoMessageEventHandler delegate - The OracleInfoMessageEventHandler delegate represents the signature of the method that handles the OracleConnection.InfoMessage event
13. OracleInfoMessageEventArgs - The OracleInfoMessageEventArgs object provides event data for the OracleConnection.InfoMessage event
14. OracleParameter - An OracleParameter object represents a parameter for an OracleCommand
15. OracleParameterCollection - An OracleParameterCollection object represents a collection of OracleParameters
16. OracleRowUpdatedEventArgs - The OracleRowUpdatedEventArgs object provides event data for the OracleDataAdapter.RowUpdated event
17. OracleRowUpdatedEventHandler - The oracleRowUpdatedEventHandler delegate represents the signature of the method that handles the OracleDataAdapter.RowUpdated event
18. OracleRowUpdatingEventArgs - The OracleRowUpdatingEventArgs object provides event data for the OracleDataAdapter.RowUpdating event
19. OracleRowUpdatingEventHandler - The OracleRowUpdatingEventHandler delegate represents the signature of the method that handles the OracleDataAdapter.RowUpdating event
20. OracleTransaction - An OracleTransaction object represents a local transaction
21. OracleXmlQueryProperties - An OracleXmlQueryProperties object represents the XML properties used by the OracleCommand class when the XmlCommandType property is Query
22. OracleXmlSaveProperties - An OracleXmlSaveProperties object represents the XML properties used by the OracleCommand class when the XmlCommandType property is Insert, Update, or Delete

Oracle.DataAccess.Client Enumerations  

1. FailoverEvent - FailoverEvent enumerated values are used to explicitly specify the state of the failover
2. FailoverReturnCode - FailoverReturnCode enumerated values are passed back by the application to the ODP.NET provider to request a retry in case of a failover error or to continue in case of a successful failover
3. FailoverType - FailoverType enumerated values are used to indicate the type of failover event that was raised
4. OracleDbType - OracleDbType enumerated values are used to explicitly specify the OracleDbType of an OracleParameter
5. OracleParameterStatus - The OracleParameterStatus enumeration type indicates whether a NULL value is fetched from a column, whether truncation has occurred during the fetch, or whether a NULL value is to be inserted into a database column
6. OracleXmlCommandType - The OracleXmlCommandType enumeration specifies the values that are allowed for the OracleXmlCommandType property of the OracleCommand class
   

Oracle.DataAccess.Types Structures

1. OracleBinary - The OracleBinary structure represents a variable-length stream of binary data
2. OracleDate - The OracleDate structure represents the Oracle DATE datatype
3. OracleDecimal - The OracleDecimal structure represents an Oracle NUMBER in the database or any Oracle numeric value
4. OracleIntervalDS - The OracleIntervalDS structure represents the Oracle INTERVAL DAY TO SECOND datatype
5. OracleIntervalYM - The OracleIntervalYM structure represents the Oracle INTERVAL YEAR TO MONTH datatype
6. OracleString - The OracleString structure represents a variable-length stream of characters
7. OracleTimeStamp - The OracleTimeStamp structure represents the Oracle TimeStamp datatype
8. OracleTimeStampLTZ - The OracleTimeStampLTZ structure represents the Oracle TIMESTAMP WITH LOCAL TIME ZONE data type
9. OracleTimeStampTZ - The OracleTimeStampTZ structure represents the Oracle TIMESTAMP WITH TIME ZONE data type

Oracle.DataAccess.Types Exceptions

1. OracleTypeException - The OracleTypeException object is the base exception class for handling exceptions that occur in the ODP.NET Type classes
2. OracleNullValueException - The OracleNullValueException represents an exception that is thrown when trying to access an ODP.NET Type structure that is null
3. OracleTruncateException - The OracleTruncateException class represents an exception that is thrown when truncation in an ODP.NET Type class occurs

Oracle.DataAccess.Types Classes

1. OracleBFile - An OracleBFile is an object that has a reference to BFILE data. It provides methods for performing operations on BFiles
2. OracleBlob - An OracleBlob object is an object that has a reference to BLOB data. It provides methods for performing operations on BLOBs
3. OracleClob - An OracleClob is an object that has a reference to CLOB data. It provides methods for performing operations on CLOBs
4. OracleRefCursor - An OracleRefCursor object represents an Oracle REF CURSOR
5. OracleXmlStream - An OracleXmlStream object represents a sequential read-only stream of XML data stored in an OracleXmlType object
6. OracleXmlType - An OracleXmlType object represents an Oracle XmlType instance

Okay, now we will move on to connection pooling as I briefly wrote of earlier.