| OnChangeEventHandler Delegate | The OnChangedEventHandlerevent delegate represents the signature of the method that handles the notification. Not Supported in a .NET Stored Procedure | 
| OracleAQAgent Class | The OracleAQAgentclass represents agents that may be senders or recipients of a message. | 
| OracleAQDequeueOptions Class | An OracleAQDequeueOptionsobject represents the options available when dequeuing a message from anOracleAQQueueobject. | 
| OracleAQEnqueueOptions Class | The OracleAQEnqueueOptionsclass represents the options available when enqueuing a message to anOracleAQQueue. | 
| OracleAQMessage Class | An OracleAQMessageobject represents a message to be enqueued and dequeued. | 
| OracleAQMessageAvailableEventArgs Class | The OracleAQMessageAvailableEventArgsclass provides event data for theOracleAQQueue.MessageAvailableevent. | 
| OracleAQMessageAvailableEventHandler Delegate | The OracleAQMessageAvailableEventHandlerdelegate represents the signature of the method that handles theOracleAQQueue.MessageAvailableevent. | 
| OracleAQQueue Class | An OracleAQQueueobject represents a queue. | 
| OracleBulkCopy Class | An OracleBulkCopyobject efficiently bulk loads or copies data into an Oracle table from another data source. | 
| OracleBulkCopyColumnMapping Class | The OracleBulkCopyColumnMappingclass defines the mapping between a column in the data source and a column in the destination database table. | 
| OracleBulkCopyColumnMappingCollection Class | The OracleBulkCopyColumnMappingCollectionclass represents a collection ofOracleBulkCopyColumnMappingobjects that are used to map columns in the data source to columns in a destination table. | 
| OracleClientFactory Class | An OracleClientFactoryobject allows applications to instantiate ODP.NET classes in a generic way. | 
| OracleCommand Class | An OracleCommandobject represents a SQL command, a stored procedure or function, or a table name. | 
| OracleCommandBuilder Class | An OracleCommandBuilderobject provides automatic SQL generation for theOracleDataAdapterwhen the database is updated. | 
| OracleConnection Class | An OracleConnectionobject represents a connection to Oracle Database. | 
| OracleConnectionStringBuilder Class | An OracleConnectionStringBuilderobject allows applications to create or modify connection strings. | 
| OracleDataAdapter Class | An OracleDataAdapterobject represents a data provider object that communicates with theDataSet. | 
| OracleDataReader Class | An OracleDataReaderobject represents a forward-only, read-only, in-memory result set. | 
| OracleDataSourceEnumerator Class | An OracleDataSourceEnumeratorobject allows applications to generically obtain a collection of data sources to connect to. | 
| OracleDependency Class | An OracleDependencyclass represents a dependency between an application and an Oracle database. Not Supported in a .NET Stored Procedure | 
| OracleError Class | The OracleErrorobject represents an error reported by an Oracle database. | 
| OracleErrorCollection Class | An OracleErrorCollectionobject represents a collection ofOracleErrors. | 
| OracleException Class | The OracleExceptionobject represents an exception that is thrown when Oracle Data Provider for .NET encounters an error. | 
| OracleFailoverEventArgs Class | The OracleFailoverEventArgsclass provides event data for theOracleConnection.Failoverevent. Not Supported in a .NET Stored Procedure | 
| OracleFailoverEventHandler Delegate | The OracleFailoverEventHandlerrepresents the signature of the method that handles theOracleConnection.Failoverevent. Not Supported in a .NET Stored Procedure | 
| OracleGlobalization Class | The OracleGlobalizationclass is used to obtain and set the Oracle globalization settings of the session, thread, and local computer (read-only). | 
| OracleHAEventArgs Class | The OracleHAEventArgsclass provides event data for theOracleConnection.HAEventevent. | 
| OracleHAEventHandler Delegate | The OracleHAEventHandlerdelegate represents the signature of the method that handles theOracleConnection.HAEventevent. | 
| OracleInfoMessageEventArgs Class | The OracleInfoMessageEventArgsobject provides event data for theOracleConnection.InfoMessageevent. | 
| OracleInfoMessageEventHandler Delegate | The OracleInfoMessageEventHandlerdelegate represents the signature of the method that handles theOracleConnection.InfoMessageevent. | 
| OracleNotificationEventArgs Class | The OracleNotificationEventArgsclass provides event data for a notification. | 
| OracleNotificationRequest Class | An OracleNotificationRequestclass represents a notification request to be subscribed in the database. Not Supported in a .NET Stored Procedure | 
| OracleParameter Class | An OracleParameterobject represents a parameter for anOracleCommand. | 
| OracleParameterCollection Class | An OracleParameterCollectionobject represents a collection ofOracleParameters. | 
| OraclePermission Class | An OraclePermissionobject enables ODP.NET to enforce imperative security and helps ensure that a user has a security level adequate for accessing data. | 
| OraclePermissionAttribute Class | An OraclePermissionAttributeobject enables ODP.NET to enforce declarative security and helps ensure that a user has a security level adequate for accessing data. | 
| OracleRowsCopiedEventHandler Delegate | The OracleRowsCopiedEventHandlerdelegate represents the method that handles theOracleRowsCopiedevent of anOracleBulkCopyobject. | 
| OracleRowsCopiedEventArgs Class | The OracleRowsCopiedEventArgsclass represents the set of arguments passed as part of event data for theOracleRowsCopiedevent. | 
| OracleRowUpdatedEventArgs Class | The OracleRowUpdatedEventArgsobject provides event data for theOracleDataAdapter.RowUpdatedevent. | 
| OracleRowUpdatedEventHandler Delegate | The OracleRowUpdatedEventHandlerdelegate represents the signature of the method that handles theOracleDataAdapter.RowUpdatedevent. | 
| OracleRowUpdatingEventArgs Class | The OracleRowUpdatingEventArgsobject provides event data for theOracleDataAdapter.RowUpdatingevent. | 
| OracleRowUpdatingEventHandler Delegate | The OracleRowUpdatingEventHandlerdelegate represents the signature of the method that handles theOracleDataAdapter.RowUpdatingevent. | 
| OracleTransaction Class | An OracleTransactionobject represents a local transaction. Not Supported in a .NET Stored Procedure | 
| OracleXmlQueryProperties Class | An OracleXmlQueryPropertiesobject represents the XML properties used by theOracleCommandclass when theXmlCommandTypeproperty isQuery. | 
| OracleXmlSaveProperties Class | An OracleXmlSavePropertiesobject represents the XML properties used by theOracleCommandclass when theXmlCommandTypeproperty isInsert,Update, orDelete. |