PostgreSQL Data Access Components

PostgreSQL Data Access Components (PgDAC) is a library of components that provides direct access to PostgreSQL database servers from Delphi, Delphi for .NET, C++Builder, and Lazarus (Free Pascal). PgDAC is designed to help programmers develop really lightweight, faster and cleaner PostgreSQL database applications without deploying any additional libraries.

PgDAC is a complete replacement for standard PostgreSQL connectivity solutions and presents an efficient alternative to the Borland Database Engine for access to PostgreSQL.


PgDAC Palette

Advantages of PgDAC Technology

PgDAC works directly through TCP/IP protocol and does not use the PostgreSQL client library. As data is transferred from socket to storage without additional buffers, the PgDAC performance is kept on the highest level. Such technology helps to avoid restrictions and slips of the pqlib library, use features of PostgreSQL backend protocol that are not implemented in it. Also Devart PgDAC offers wide coverage of the PostgreSQL feature set and emphasizes optimized data access strategies.

Wide Coverage of PostgreSQL Features

By providing access to the most advanced database functionality, PgDAC allows developers to harness the full capabilities of the PostgreSQL server and optimize their database applications. PgDAC features complete support of fast record insertion, Asynchronous Notification, PostgreSQL sequences, the possibility to retrieve the last inserted OID value, notices, and more.

Native Connection Options

PgDAC does not require PostgreSQL client software installed what heightens its performance. PgDAC-based database applications are easy to deploy, do not require installation of other data provider layers (such as BDE), and tend to be faster than those that use standard data connectivity solutions.

Optimized Code

The goal of PgDAC is to enable developers to write efficient and flexible database applications. The PgDAC library is implemented using advanced data access algorithms and optimization techniques. Classes and components undergo comprehensive performance tests and are designed to help you write high-performance, lightweight data access layers.

Compatibility with Standard Data Access Components

The PgDAC interface retains compatibility with standard VCL data access components, like BDE. Existing BDE-based applications can be easily migrated to PgDAC and enhanced to take advantage of PostgreSQL-specific features. Project migration can be automated with BDE Migration Wizard.


How Does PgDAC Work?

PgDAC connects to PostgreSQL directly without using client software.

In comparison, the Borland Database Engine (BDE) uses several layers to access PostgreSQL, and requires additional data access software to be installed on client machines.

The BDE data transfer protocol is shown below.

BDE Connection Protocol

BDE Connection Protocol

PgDAC optimal transfer route:

PgDAC Connection Flow

PgDAC Connection Flow


Key Features

The following list describes the main features of PostgreSQL Data Access Components.

  • Direct access to server data without using client library. Does not require installation of other data provider layers (such as BDE and ODBC)
  • Full support of the latest versions of PostgreSQL Server
  • Support for all PostgreSQL Server data types
  • Disconnected Model with automatic connection control for working with data offline
  • Local Failover for detecting connection loss and implicitly reexecuting certain operations
  • All types of local sorting and filtering, including by calculated and lookup fields
  • Automatic data updating with TPgQuery, TPgTable, and TPgStoredProc components
  • Unicode and national charset support
  • Supports many PostgreSQL-specific features, such as notifications, notices, and sequences
  • Advanced script execution functionality with the TPgScript component
  • Support for using macros in SQL
  • Easy migration from BDE with Migration Wizard
  • Lets you use Professional Edition of Delphi and C++Builder to develop client/server applications
  • Includes annual PgDAC Subscription with Priority Support
  • Licensed royalty-free per developer, per team, or per site

See All Features


PgDAC Design-Time View

PostgreSQL Data Access Components design-time