How to apply incremental updates to a .data file stored in the file system
This procedure assumes that you have already created the data object design (.datadesign) and generated the initial data object store (.data).
1 In the layout editor, right-click in an empty area of the data object design, then choose Enable Incremental Update.
2 In Navigator, right-click the data object design, then choose Generate Data Objects.
3 In Incremental Update, do the following:
1 Select Use incremental update.
2 Select the .data file to update.
3 In Target data file name, type a temporary .data file to which to write the new data. This step is required because a file saved in the file system cannot be read and written to at the same time.
Figure 2‑16 shows an example of values specified in Incremental Update. In this example, Employees.data is the file to update, and Employees_Temp.data is the temporary file to which to write the new data.
Figure 2‑16 Incremental Update
4 Choose OK.
4 In Input Parameters, provide the parameter values to specify which data to add to the .data file.
Figure 2‑17 shows an example of a parameter that displays a list of values from which you select a year or years whose data to add.
Figure 2‑17 Input Parameters
5 In Navigator, delete the original .data file. In the example shown in
Figure 2‑16, you would delete Employees.data.
6 Rename the temporary .data file to the name of the original .data file. In the example shown in
Figure 2‑16, you would rename Employees_Temp.data as Employee.data.
When you publish a data object to an iHub Encyclopedia volume, you grant specific users or user groups access to the data object. This type of security is implemented in iHub, and users either have access to all the items in the data object, or none at all. For information about implementing security in iHub, see Managing an Encyclopedia Volume.
Using Actuate BIRT Designer in conjunction with iHub, you can apply more granular security rules to control user access to individual items in a data object, down to which data set columns, cube dimensions and measures, and data rows are available to particular groups of users. For information about implementing this type of security, see
Chapter 20, “Controlling user access to report pages and data,” later in this book.
| Maintaining a data object |
Changes you make to any item in a data object propagate to the reports and dashboard gadgets that use that item. For example, if you add a dimension to a cube in a data object, all reports and gadgets that use that cube have access to the new dimension. This automatic-update functionality is useful for applying necessary updates, such as connection properties in a data source, to all reports and gadgets.
However, the automatic-update functionality also means that you have to be careful with the type of change that you make. The following changes can cause errors in reports and gadgets:
Renaming a data object, data source, data set, or cube
Deleting a data object, data source, data set, or cube
Deleting items within a data set or a cube, such as a column, dimension, or measure
To fix errors resulting from a renamed or deleted data object item, the user has to recreate the report element or dashboard gadget to use a different data object item.
Before changing a data object, run an impact analysis report to determine how many files, and which files, are affected. For information about this process, see
Chapter 22, “Performing impact analysis.”
