Load Control

Load control is the mechanism to ensure the fastest possible Macro loads. These loads will not load faster than the target application is processing the data and will stop if an error occurs in the target application. Load control is fully implemented in DataLoad Professional but is restricted to 5 record loads in DataLoad Classic so it can be used for demonstration and trial purposes.

Introduction

Macro loads are simple to create and run, however they send data and commands blindly to the target application. This means it is very easy to send data faster than it can be handled, which may result in navigation steps being missed and loads not performing correctly. Delays help to ensure these problems do not occur but they tend to slow down loads more than is necessary. Finally, because macro loads are blind they continue to run even after an error has occurred in the target application, which means these loads cannot be left unattended. Load control provides a feedback mechanism from the target application which DataLoad will use to control the rate at which data is sent.

Creating a Feedback File

To be able to use load control to control your load the target application must be capable of writing its activities to a log file accessible by DataLoad. The rest of this section will assume you are loading into Oracle Applications, but the principles are the same no matter what application you are loading into.

Before DataLoad can be configured to use feedback Oracle Applications must be configured to record all its activities to a file. Furthermore, that file must be accessible to DataLoad. If you are using 'Web Forms' or 'NCA' then the forms software is run on a server and not on your PC. You should speak to your DBA to find out how the forms software can write to a location that is also accessible from your PC. The Oracle Applications feedback file is generated by running Oracle Forms in 'record' mode. The page "Oracle Forms Record and Play - Setup" describes how to setup Oracle Forms to run in record mode. Note that page also talks about running the forms in playback mode but for load control it is only necessary to run the forms in record mode.

Configuring DataLoad

Load control is configured using the Options form, which is accessible by selecting 'Options' from the 'Tools' menu or by clicking on the tick icon in the toolbar.

To turn on load control the option 'Wait for feedback during load' must be ticked.

Next, the location and name of the feedback file must be entered. If the file already exists then you can click on the 'Browse' button to find the file.

Load control can wait on data or commands to appear in the feedback file before DataLoad continues its load. Either or both of these options can be used and whether data or command feedback is turned on depends on the status of the two 'Wait for ... feedback' checkboxes on the Options form.

When data feedback is turned on DataLoad will not continue with the load until the data it has sent to the application appears in the feedback file.

Similarly, when command feedback is turned on DataLoad will not continue with the load until evidence of the command being executed is in the feedback file. Obviously the name of the DataLoad command used will not appear in the feedback file. Therefore you need to tell DataLoad what feedback text to look for in the feedback file that will signify the command execution has been completed. The feedback text for each command is entered in the Commands form in DataLoad, which can be opened by selecting 'Commands' from the 'Edit' menu or by clicking on its shortcut icon. The Commands form will look like the following:-

Note If your Commands form does not include the 'Feedback' and 'Description' columns then your load was created in an old version of DataLoad and the command definition have been saved in your load for load portability. To refresh your commands to include the extra columns please click on 'Load Defaults' in the Commands form and answer 'Yes' at the prompt. Note that this will overwrite any changes you have made to command definitions.

When command feedback is turned on DataLoad will stop the load until the feedback text associated with that command is added to the feedback file. The default feedback text supplied with DataLoad is for Oracle Applications 11i, although most of the text will be appropriate for any applications using Oracle Forms. Whatever software you are loading into it is important to ensure that the text in the feedback column is actually the text that appears in the feedback file when the command is executed.

Some commands are generic in nature and can cause many different actions in the target application and hence may result in different text being written to the feedback file. For such commands the special feedback text '[various]' can be used. This tells DataLoad that the command will result in something being written to the feedback file but it is not possible to say what. Therefore, when DataLoad sends such a command it will stop the load until any new text is written to the feedback file.

In many applications data will not be written to the feedback file until after a command has been executed. For instance, in Oracle Forms data entered into a cell will not be written to the feedback file until you TAB out of that cell. If data and command feedback is turned on the TAB command will not be sent until the data is written to the feedback file but that won't occur until the TAB is sent, so the load stops and is stuck in an infinite loop. To handle such situations the option 'Check for data after subsequent command' can be used. When this is ticked DataLoad does not check the data has appeared in the feedback file until after the next command has been sent. When that command has been sent DataLoad then checks that the data is in the feedback file and when the data has been found DataLoad then waits for the command feedback to appear.

Running a Feedback Controlled Load

Once the Load Control section of the Options form has been configured you can run your load in the normal way. The load will work as normal however the speed of the load will be controlled by the feedback from the target application. Therefore the load will run as fast as possible without overrunning the target.

Final Notes

When using Load Control set all delays to be 0 except 'Window is activated', which should still be used to enable the target application to become active before data is sent to it. The 'Advanced' delays should also be left unchanged. All other delays should be set to 0 , however, because the load control will ensure DataLoad does not send data too quickly.
Oracle Forms will often be running on a server remote from your PC. This will probably mean the feedback file will also be remote from your PC and will be accessed across a network. This doesn't present any problems as long as the network speed is acceptable. For that reason load control is not recommended to be used over a modem connection but most company networks will be ideal.
Load control will wait for commands and data to be processed by the target application, but it does not wait on keystroke or mouse click cells. If this causes a problem a delay should be added after the problem cell using the *SL command or the keystroke or mouse click should be created as a command and the appropriate feedback text included with that command definition.