See AlsoPutting
Long and long raw columns of an Oracle database can contain up to 2 gigabytes
of data. Data of less than 64K bytes can be put into the database using simple
assignment, but data exceeding 64K bytes must be put into the database using
AppendChunk. The Oracle database libraries do not allow putting of data in
multiple pieces, so the data is held internally and put in one piece upon an Update.
Fetching
Long and long raw columns of an Oracle database can contain up to 2 gigabytes
of data. This makes it impractical to retrieve all data from a long or long raw
column automatically when it is selected. Instead, the first 64K bytes is
retrieved and the Oracle ROWID is cached locally so that the row containing the
long or long raw column can be located and then retrieved when using the GetChunk
method. If the Oracle ROWIDs cannot be obtained on a query with a long or long
raw column, then the long or long raw column will not be accessible and an
error will be generated if field access is attempted.
Editing
Before an Edit can be started, a column's locally cached value is compared
with its current database value. If the values match, the edit proceeds; otherwise
an error is generated. Since long and long raw columns may contain up to 2
gigabytes of data, no comparison is done before an Edit is started.