Direct Oracle Access
|If you are using Borland's Delphi or C++Builder to
develop Oracle applications, then the Direct Oracle Access component set can
help you to make a seamless integration between this great development tool
and database system. Not only will your application take maximum advantage
of both products, your application development process will also benefit
from the following key features:
Both online transaction and batch processing applications can
benefit from Oracle's performance features. Direct Oracle Access, as the
name suggests, directly accesses the Oracle Interface. This guarantees
optimal performance for standard database access functions. Support for
Array Fetching, Array DML, PL/SQL Blocks, PL/SQL Tables, Local Statement
Caching and the Direct Path Load Engine enable you to optimize your
application's performance critical functions even more.
A Direct Oracle Access application does not require middleware like
the BDE or ODBC, it merely requires Oracle SQL*Net or Net8. Consequently you
can deploy your application without many of the version dependency or
configuration problems typically involved with middleware installation.
|Oracle Package support
Most PL/SQL code in Oracle databases is programmed in packages.
Direct Oracle Access provides a TOraclePackage component that allows you to
easily call packaged program units without detailed declarations of these
program units and their parameters.
Furthermore Direct Oracle Access includes a Package Wizard that can generate
classes to encapsulate the program units and record types defined in
packages. This will make your Oracle packages a natural extension of the
Object Pascal or C++ language.
The Package Wizard
The dataset component in Direct Oracle Access supports Oracle
record locking, record refreshing, server generated values, automatic
sequence value generation, and BLOB compression. Master/detail relations can
automatically be setup if a foreign key exists between the master and detail
table or if the master table contains one or more collection columns or
attributes (nested table or varray).
The TOracleDataSet can use much of the information in the Oracle Dictionary
at run time. Server Constraints can be checked on the client, and constraint
error messages can be read from a message table. Format masks, range values
and default values can also be read from the dictionary. This allows you to
create applications with a minimum amount of 'database knowlegde' compiled
into the executable, dynamically adopting changes in the database without
even recompiling it.
|Query By Example mode
The TOracleDataSet component has a Query By Example mode that
enables you to provide QBE Forms in your application without any additional
programming, and without any additional components or controls. The
resulting QBE queries are performed on the Oracle Server, so that
performance will be optimal and network traffic will be minimal. The user
can supply simple query values such as JONES or 100, can
include wildcard characters for string values such as JON%, and can
include comparison operators such as >, <, NOT,
and so on.
Query By Example
To monitor the database access activities of your Direct Oracle
Access application you can use the Oracle Monitor utility. It displays the
SQL, variables, timestamp, elapsed time, network statistics, database
statistics and query execution plan of each activity. This can be helpful to
find performance bottlenecks, for tuning purposes, and to solve application
The Oracle Monitor
|Alert and Pipe events
The Oracle Server includes a dbms_alert and dbms_pipe package for
event processing. The TOracleEvent in Direct Oracle Access can function as a
receiver for these events. It works in a background thread of your
application, and can propagate database events to the familiar object
events. These events can occur synchronously or asynchronously with the main
thread of your application.
Alert and Pipe events
If you need to execute many data definition language (DDL)
statements, for example to perform the database installation part of your
application, you can use the TOracleScript component. It has a property
editor that allows you to develop the script and the individual commands.
The extendible script language follows the basic SQL*Plus syntax and
supports all SQL statements. It also supports substitution variables to make
To take advantage of the Advanced Queuing option of Oracle8 you can
make use of the TOracleQueue component. The TOracleQueue component
encapsulates the basic functionality of the DBMS_AQ package. It provides a
convenient way to enqueue messages into a queue or to dequeue messages from
a queue. Messages can be dequeued in a background thread of your
application, and the events that are generated in threaded mode can occur
synchronously or asynchronously with the main thread of your application.
In server applications that frequently need to create sessions to
process requests from client applications, it may be useful to use
connection pooling. Without a pooling concept, each request could lead to an
actual database logon and logoff. By using the TOracleSessionPool component,
you can maintain a pool of database sessions that can be used and reused for
different requests. You can define the minimum an maximum number of sessions
in the pool, define the TimeOut behavior for idle sessions in the pool, and
preset the username, password and database.
|Support for Oracle
Direct Oracle Access supports many Oracle specific features.
Besides the features mentioned above, it supports Oracle8 and Oracle8i
features like LOB Locators, Objects & References, XMLTYPE, Timestamps,
Scrollable Queries, Password Expiration, External Procedure development, and
the Oracle Services for MTS.
Direct Oracle Access requires a Windows 95, 98, ME, NT4, 2000, XP, Vista or
Windows 7 client, with a 32 bit SQL*Net, Net 8, Net 9, Net 10 or Net 11
installed. The supported Oracle Server versions are 7.x, 8.x, 8i, 9i, 10g
and 11g on any platform. Direct Oracle Access is available for all recent
versions of Delphi and C++Builder.
You can download a fully functional
trial version to try out Direct Oracle Access yourself. Visit our
ordering page for ordering details and price information. We have a
customer list available if you want to get an impression of what
organizations are using Direct Oracle Access.
If you want a second opinion or additional info about Direct Oracle Access,
you can read the following:
- If you can read German, you can check out the review (PDF, 225KB) that appeared in the May/June
issue of Der Entwickler.
|In 3 consecutive years Direct Oracle Access finished in the top 4 of
the Delphi Informant Readers Choice Awards in the category "Database
Connectivity", which is an excellent result for a component set that is
specifically targeted at Oracle.