Page 62 - Building Digital Libraries

Acquiring, Processing, Classifying, and Describing Digital Content

• Modern file systems provide highly effective error correc-
tion and extremely reliable storage solutions that do not
require ex ternal programs to be used.
• Higher safety can be achieved by using storage designed to
pre serve integrity that depend on cryptographic signatures
to trans fer and maintain files more conveniently, efficiently,
and reliably than locally developed scripts. Numerous com-
mercial solutions such as Amazon Glacier are available at
low cost.

While libraries frequently modify files containing predominantly textual
content so they will be much easier to manage, this practice is much less
common for other types of files such as images, audio, and video—even
when the file modified is a derivative copy. Many file formats, including
all widely used image, audio, and video formats used in library repository
systems, support internal metadata. Internal metadata affects the findabil-
ity, usability, and migratability of resources, yet the dominant thinking as
of this writing is still that such modification somehow alters the object in
undesirable ways. Modifying the metadata does not modify the rest of the
file at all, and retaining inaccurate and incomplete metadata within objects
is of questionable value.
Having said this, there are workflow and administrative benefits to
retaining files in a specific state, and the benefits of updated internal meta-
data can be achieved through mechanisms such as retaining multiple ver-
sions or outputting the latest and most complete internal metadata when
the object is rendered or migrated.

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