Palm OS Database

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File Format
Name Palm OS Database
Extension(s) .pdb, others
MIME Type(s) application/vnd.palm

A Palm OS Database is the normal format in which data is stored on a Palm OS-based device. These devices lack a normal filesystem, and instead store everything as part of a database. The .pdb extension is what ends up on files containing data exported from a Palm device to another system such as a PC.

The one other format used on a Palm device is PRC, or Palm Resource Compiler. PRC can be considered to be a separate format, or it can be considered to be a subtype of PDB.


Format details

There is a 72-byte header, followed by a record list which begins with a 6-byte header. If you prefer, you can think of these two headers as one 78-byte header.

After the record list is an optional "app info" segment, then an optional "sort info" segment, then the data segments for the records. The segment sizes are not stored explicitly; a segment is assumed to end where the next one begins, or at the end of the file.


There's no simple way to identify a PDB file as such, though a known data type can be identified by the 8 bytes at offset 60.

For how to distinguish PDB from PRC, see PRC (Palm OS)#Identification.

Specific formats

The type of data stored in the file is indicated by the type and creator codes, which are two FourCCs (a total of 8 ASCII characters) that appear starting at file offset 60.

There are separate articles for the following formats:

Additional formats might be listed at Category:Palm OS Database. For a longer list of formats, see the MobileRead Wiki.


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