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Oracle Performance Tuning and Optimization
(Publisher: Macmillan Computer Publishing)
Author(s): Edward Whalen
ISBN: 067230886x
Publication Date: 04/01/96

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Forms Designer

The Forms Designer is the part of Power Objects used to build applications. The Forms Designer uses a drag-and-drop approach to allow you to drag tables from the tables window into the form design window, as shown in Figure 35.10.


Figure 35.10  The Power Objects Forms Designer.

Applications developed with the Power Objects Forms Designer are typically fairly optimized. Unfortunately, Oracle Power Objects does not give you a view into the SQL statements that will be used to execute your transactions. However, you can view the SQL statements by using some user properties and the EXEC SQL command within some objects.

Reports Designer

The Reports Designer is the part of Power Objects used to build graphical reports. The Reports Designer also uses a drag-and-drop approach to allow you to drag tables from the tables window into the report design window, as shown in Figure 35.11.


Figure 35.11  The Power Objects Reports Designer.

As with the Forms Designer, applications developed with the Power Objects Reports Designer are typically fairly optimized. Unfortunately, as with the Forms Designer, Oracle Power Objects does not give you a view into the SQL statements that will be used to execute your transactions. However, you can view the SQL statements by using some user properties and the EXEC SQL command within some objects. This is not nearly as easy to do as it is with some of the other tools described in this chapter.

Classes

Classes are a key part of Oracle Power Objects. By using classes, you can reuse many of the objects you develop. If you use classes to contain reusable objects like labels, when you change the class, all other objects that use that class change automatically.

The Class design window also uses a drag-and-drop interface (see Figure 35.12). It is easy to create reusable classes very quickly. If you take the time to develop classes you can reuse, you can improve your efficiency in the long run.


Figure 35.12  The Power Objects Class Designer.

Power Objects gives you the ability to put these classes in libraries that can easily be used by others. Simply create a library and drop your classes or objects into it.

Review of Power Objects

As you have seen, Oracle Power Objects can be quite easy to use and can help you quickly develop and deploy applications. Unfortunately, it does not provide a view into the SQL statements that Oracle Power Objects is using in its transactions. You can use the EXEC SQL command in some objects by defining that as a function, but because you don’t have the original SQL statement to work from, modifying them is difficult.

As a small-application builder, Oracle Power Objects is highly recommended. If you want to build a small application for home or work, this is the ideal tool. If you need to build a large, optimized application, I recommend that you use Developer/2000.

Third-Party Tools

Of the third-party tools available on the market today, several of the most popular are PowerBuilder from Powersoft, Gupta SQLWindows, and Borland Delphi. The following sections describe these tools with an emphasis on how to get the most performance out of them. All these tools are excellent products; I make no judgment about which tools are better or which will better suit your purposes. That choice is up to you.

Delphi from Borland

Borland’s Delphi has grown in popularity over the last few years and is now one of the top-selling application development tools. Delphi is a graphical, drag-and-drop tool that is very easy to use and very powerful.

Delphi comes with ODBC drivers; by adding the SQL Links native drivers, you can connect to SQL*Net directly. It is much more efficient to build native Oracle applications than it is to use ODBC. ODBC essentially takes the calls to it and translates them to SQL*Net calls, causing unnecessary overhead.

Delphi consists of two main components: The forms developer is simply called Delphi, and the reports developer is called ReportSmith.

Delphi Forms Developer

As is true with the other tools described in this chapter, the SQL statements generated by Delphi are generally good. If you do need to alter the SQL statements to make them more efficient, you can do so easily. While in the forms editor, you can easily modify the SQL statement, as shown in Figure 35.13. To edit the SQL statement, follow these steps:

1.  Highlight the TQuery box in the forms editor or select it from the pull-down menu in the Object Inspector.
2.  Double-click the three dots next to the SQL selection.
This opens the String List Editor, where you can view or modify your SQL statements (see Figure 35.14).


Figure 35.13  Invoking the String List Editor.


Figure 35.14  The String List Editor.

Once you open the String List Editor, you can modify and optimize the SQL statements that will be used in this application.

Depending on the complexity of your application and the database, you may not have to change the automatically generated SQL statements. But the capability is there if, for example, you want to change the SQL statement to invoke a stored procedure or function.

ReportSmith

As with the Delphi forms development tool, the SQL statements generated by ReportSmith are generally good. If you have to alter the SQL statements to become more efficient, you can do so easily. While in ReportSmith, you can easily modify the SQL statement as shown in Figure 35.15. With ReportSmith, you can alter the SQL statements while you design the report or afterwards. To edit the SQL statement, follow these steps.

1.  If you are altering the SQL statement for an already designed report, simply double-click the SQL icon in the toolbar at the top of the window (see Figure 35.15).


Figure 35.15  Invoking the Report Query tool.

2.  This opens the Report Query window, where you can modify the SQL statement as shown in Figure 35.16.


Figure 35.16  The Report Query tool window.

Depending on the complexity of your report, you may want to modify the SQL statements or add hints that can be used by the Oracle optimizer. Depending on the complexity of your application and the database, it may not be necessary to change the automatically generated SQL statements. If necessary, however, you can change the SQL statement to invoke a stored procedure or function.


TIP:  Depending on the size of the query and the amount of data to be scanned, you may see a huge performance increase by using the Parallel Query option. Use the Report Query tool to add parallel query hints to your SQL statements.


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