Working with Large Objects

This section describes functions that allow you to:

• create large objects.
• open, close, and delete large objects.
• return and change the current position within a large object.
• read from and write to large objects.
• copy a large object.

Generally, you use the functions described in this section in the following order.

1. You use lld_create() to create a large object. It returns a pointer to an lld_locator row that points to the large object.

   If the large object already exists, you can insert an lld_locator row into a table in the database to point to the object without calling lld_create().

2. You can pass the lld_locator type to the lld_open() function to open the large object you created. This function returns an LLD_IO structure that you can pass to various Large Object Locator functions to manipulate data in the open object (see Step 3).

   You can also pass the lld_locator type to the lld_copy(), lld_from_client(), or lld_to_client() functions to copy the large object.

3. After you open a large object, you can pass the LLD_IO structure to:
   • lld_tell() to return the current position within the large object.
   • lld_seek() to change the current position within the object.
   • lld_read() to read from large object.
   • lld_write() to write to the large object.
   • lld_close() to close an object. You should close a large object if the transaction in which you open it is aborted or committed.

The functions within this section are presented in alphabetical order, not in the order in which you might use them.