Rescue for 4D Data - Documentation

DOCUMENTATION RESCUE FOR 4D DATA - Viewer

Viewer

Viewer :

Viewer makes it possible to visualize and analyze a data file.

The results provided by Viewer can be completely erroneous if the database is damaged and the viewer does not see the damage. For reasons of speed, Viewer does not perform all the validity tests which Doctor performs. It does not delve deeply into the structure of the records; it only checks the total state.

If the data is seriously damaged, the following message may appear:

"I Found Very Big Error In Data File. You must Use Doctor Before Use Viewer.".

You might notice some sluggishness when using Viewer. This slowness is caused by Windows™ activating its cache memory. Using the System Monitor, you can see this in the utilization factors of the Windows™ memory. The activation of this cache reduces the performance of Viewer --- as it does for all other applications as well.

To accelerate the file processing time, you can iconize the window.

Analyze the Data File

To launch or halt the analysis

To launch or halt the analysis, click on the button.


By default, the analysis is carried out in the Map form. The Map button is selected.

In the Map form, each color square represents 512 bytes (512 bytes = four 4D blocks ).

Its color (and, thus, its type in Rescue For 4D) is calculated according to the type most representative of these 4 blocks. You may change the color for each type in the Preferences.

Example: Say you have 4 Blocks: 3 occupied by the data in the table 3, and 1 occupied by a SRA in table 4. Rescue for 4D Data will reveal this block as being occupied by table 3.

This limitation is due to the memory needs of Viewer. If several Blocks were not gathered, a database of 50 Tables and approximately 100 MB would take approximately 2.4 MB of read-write memory instead of 800 KB (that is to say, three times the original size).

Tests were made during the development of Rescue For 4D Data which show that, had we dynamically managed the block size corresponding to the memory and the database size, the performance would have decreased by at least 30%.

However, all calculations are made using the real data.

This mode enables you to have a supplemental data analysis. It provides:

A quantified analysis of the database occupation. Percentages of the pieces are compared to the total size of the file (space used and not used).
Advice on 4D configuration (parameters memory to allocate to 4D, in order to improve performance) and,
The fragmentation rate of data - > whether or not to use 4D Util.

To obtain the supplemental data analysis, select the Text form button:

Save an Analysis

You can Save the analysis by selecting Save from the File menu.

You can open it with an RTF (RichTextFormat) text editor.