All the functions mentioned in this section are applicable to internal LOBs only, except ora-lob-load-from-file.
Before modifying a LOB, the corresponding record must be locked. See the discussion in Locking.
If you make several modifications to a LOB which has functional or domain indexes, it is useful to wrap several calls of modifying functions in a pair of ora-lob-open and ora-lob-close. That means that the indexes will be updated once (when ora-lob-close is called), which saves work. Note that after a call to ora-lob-open, ora-lob-close must be called before any call to commit.
To append the contents of one LOB to another, use ora-lob-append.
You can copy all or part of a LOB into another LOB using ora-lob-copy.
ora-lob-load-from-file loads the data from a file LOB into an (internal) LOB.
You can erase (that is, fill with the 0 byte or with Space character) all or part of a LOB using ora-lob-erase.
You can reduce the size of a LOB using ora-lob-trim.
If you need to make multiple updates to a LOB you can optionally create a transaction using ora-lob-open and ora-lob-close call. This may save work on the server side.
LispWorks User Guide and Reference Manual - 21 Dec 2011