Chapter 11. Loading Large Objects
The Oracle database supports large object (LOB) datatypes that allow you to store up to four gigabytes of text or binary data in a single database column. SQL*Loader allows you to load data into these LOB columns. As you might imagine, there are some specific issues that come into play when you load LOBs. First off, large objects are, well, large. It’s not likely that you’ll have one large data file containing LOB data for hundreds or thousands of records. The more likely scenario is that each LOB that you load will be in its own file. Thus you need a mechanism for pointing SQL*Loader to the appropriate file for each LOB value that you load. The other issue you’ll encounter pertains to flexibility in terms of different input data formats. SQL*Loader is quite flexible when it comes to loading scalar data—you can deal with almost any imaginable file format. But when it comes to loading LOB data, you have a more limited set of options.
About Large Objects
In this section we’ll examine what large objects are, explain the data used in the examples in this chapter, and show the options for loading LOB data.
What Are Large Objects?
Oracle uses the term large object, usually abbreviated to LOB, to describe a particular class of scalar datatypes that can be used to store large amounts of data in a single database column. A LOB can be one of the following four types:
- CLOB
A datatype that holds up to four gigabytes of character data.
- NCLOB
The national language ...
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