What operations are defined on BLOBs?

Oracle supports binary large objects (BLOBs) up to 2 gig in size, the glossies say. My question is, how dows a client access those BLOBs? Can they only be inserted and extracted as a whole (might take a while and in case of a video clip, it might not be what the user wants), or can the BLOB be accessed using standard file semantics (read/write/seek/grow/truncate)? Are BLOBs treated in any special way as far as storage management, backup, security, transactions are concerned? More specifically are they stored in the database file(s) or somewhere else?

Anwsers via e-mail, please

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Thomas M. Hoberg   | Internet: tmh_at_first.gmd.de
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