Copyright: Version 3.0f
Citation: © 1997, Cerious Software Inc.


Introduction

With the registered version of ThumbsPlus, Cerious Software provides the ThumbsPlus Database Utilities (TDButil) to convert, repair, and compact ThumbsPlus databases. The user interface is simple – a small window with three options on the Database menu (Convert, Repair and Compact, naturally). Select a function, then select the database to process.

Exclusive access to the database is required for all three functions – you cannot have the database open in ThumbsPlus, or open from any other system on the network.

Database | Convert

Database | Repair

Database | Compact

Troubleshooting


Converting Version 2.x Databases

The "Convert" option allows you to convert ThumbsPlus version 2 databases (.TUD) to version 3 format (.TDB). Because ThumbsPlus now stores a lot of information about files that was not saved in version 2, there are some limitations to the conversion process:

1	Because the volume type was not stored in version 2, the conversion utility cannot tell the difference between a CD-ROM and other removable media. Therefore, converted CD-ROM volumes will have a diskette icon in the directory list rather than a CD-ROM icon.

2	The old format did not store volume serial numbers, so removable disk matching is performed on the volume label only.

3	There are several items of file information that were not stored in the old database. These items will not be shown for thumbnails in version 3 until they are updated:

•	Image dimensions (width and height).

•	Image color format and depth.

•	Image resolution (dpi).

•	File size

1	Thumbnails were stored in the database with a gray background in version 2. These gray backgrounds are converted to version 3. When you update the thumbnails in version 3, the gray backgrounds will be replaced with the current background color.

You can combine multiple .TUD files into a single TDB file by re-using the same file name for the "Convert To" database.


Repairing ThumbsPlus Databases

ThumbsPlus databases are quite complex, and may become damaged in several ways. The most likely is interrupted disk updates when the computer loses power or crashes. Other causes are damaged disk information (FAT tables, directories, cross-linked files, etc.). You should run SCANDISK or CHKDSK regularly to let you know that these kinds of problems have occurred.

Obviously, the primary way to correct database problems is to reload from backups. You do make backups regularly, don't you? That hard disk is not going to last forever!

Should the database become damaged, you may receive database (TPDB) errors, GP faults in TPDB.DLL, or missing or garbled thumbnails. Though not a substitute for a regular backup program, the Repair utility will do its best to recover as much of the information in the database as possible.

Note that the Repair utility requires exclusive use of the database. On Windows 3.1, it does not multi-task, so while repairing a database on 3.1 or 3.11, you will not be able to perform other tasks.


Compacting ThumbsPlus Databases

This option compacts (purges) a database so that deleted space is recovered and made available on your hard drive. Note that this option is needed much less frequently in version 3 than purging was in version 2 because the new ThumbsPlus database software automatically re-uses any deleted space for new thumbnails. However, if you remove many thumbnails and do not plan to make more, you can use this option to purge.

Note that compaction copies the database to a new file, so you must have enough room on the disk for a copy of all the thumbnails. Depending on the number of deletions performed recently, this may be nearly the size of the original database.

If the compacting process is interrupted by a system shutdown or power failure, there will be a file with the same name as the original database and the extension '.tD~' which you should delete.


Troubleshooting

The most common problems with the ThumbsPlus Database Utilities are:

1	Insufficient disk space. Both the Convert and Compact options require disk space to write the resulting file. Generally, there must be at least as much space as the original file.

2	All utilities require that the database be locked exclusively.

3	If they are damaged extensively, databases cannot be repaired, and should be reloaded from a backup instead. Another thing that occasionally works is to Compact rather than repair, although if the database is severely damaged, Compact may fail (or many thumbnails may be missing from the compacted database).