Quote from documentation
The LOB datatypes for character data are CLOB and NCLOB. They can store up to 8 terabytes of character data (CLOB) or national character set data (NCLOB).
and this is another quote from same page:
The CLOB and NCLOB datatypes store up to 128 terabytes of character data in the database. CLOBs store database character set data, and NCLOBs store Unicode national character set data.`
I am little confused, there is some misunderstanding in documentation or i miss something?
The difference stems from the fact that you can define LOBs with different "chunk" sizes. Plus their maximum size is limited by the number of database blocks used for them. If you create a database (or tablespace) with a larger blocksize this means a LOB can contain more data.
CLOB objects can store up to
(4 gigabytes -1) * (the value of the CHUNK parameter of LOB storage)of character data
And the next sentence describes the relation to the blocksize:
If the tablespaces in your database are of standard block size, and if you have used the default value of the CHUNK parameter of LOB storage when creating a LOB column, then this is equivalent to
(4 gigabytes - 1) * (database block size).
