Virtual methods for Blob operations

Blobs are a special feature of databases because they allow one to access the contents of a "cell" from the API without using SQL (usually no SQL can be used to manipulate a blob's contents: an SQL statement is used to create, delete or retreive a blob, but the contents is accessed through the API).

Libgda encapsulates all blob operations in objects which must be implemented by each provider if they want to support blobs; otherwise binary data may still be used if supported by the database, but the whole binary data is transfered in the SQL statement which is not suitable for large data.

get_length()

To write.

read()

To write.

write()

To write.

write_all()

To write.