OracleClient Data Access Components

OracleClient Data Access Components (OracleClientDAC) is a feature-rich and high-performance library of components that provides native connectivity to Oracle from Delphi for both 32-bit and 64-bit Windows platforms. OracleClientDAC-based applications connect to Oracle directly through the ADO.Net OracleClient, which is an Oracle Data Provider for .NET (ODP.Net). OracleClientDAC aims to assist programmers in developing of fast and native Oracle database applications. OracleClientDAC allows developers to take advantage of advanced Oracle database functionality, including Real Application Clusters, self-tuning statement cache, and fast connection failover.

OracleClientDAC, a high-performance and feature-rich Oracle connectivity solution, is an efficient native alternative to the Borland Database Engine (BDE) and standard dbExpress driver. It provides both possibility of connection to Oracle by means of native Oracle data access and direct access to Oracle without Oracle Client.

OracleClientDAC-based DB applications are easy to deploy, do not require installation of other data provider layers (such as BDE or ODBC), uses ADO.Net technology and that's why they can work faster than the ones based on standard Delphi data connectivity solutions.

Component List


This class is responsible for establishing connection with Oracle database.


This class is responsible for executing a Transact-SQL statement or stored procedure against an Oracle database.


This class is responsible for providing a way of reading a forward-only stream of rows from an Oracle database.


This class is responsible for filling Virtual Table components with data and update an Oracle database.


This class uses SQL statements to retrieve data from tables in an Oracle database and pass it to one or more data-aware components through a TDataSource object. This component provides a mechanism for updating data.


This class is responsible for retrieving and updating data in a single table in an Oracle database without writing SQL statements.


This class is responsible for executing stored procedures and functions in an Oracle database.


  • Direct access to server data. Does not require installation of other data provider layers (such as BDE and ODBC)
  • Transmission is via XML format, therefore can pass through firewalls
  • Full support for the latest versions of Oracle
  • Support for all versions of Oracle Clients, including Instant Client
  • High overall performance
  • High performance in batch processing. This is controlled by UpdateOptions.UpdateBatchSize property
  • Support prefetching rows - specifies the number of rows that are to be fetched per server round trip. This is controlled by FetchOptions.RowsetSize property
  • CachedUpdates operation mode which is controlled UpdateOptions.UpdateMode property
  • Automatic data updating with TOracleClientQuery, TOracleClientTable, and TOracleClientStoredProc components
  • Fast data retrieval with TOracleClientDataReader component or using Server CursorKind property of the TCustomDbDataSet
  • Automatic record locking
  • Automatic query preparing
  • Data export and import to/from XML
  • Easy to deploy

Supported Oracle Servers

  • Oracle 12c, 11g, 9i, 8i, 8.0
  • Oracle Express Edition 11g and 10g