Oracle Error Message
OCI-31004: Length string of the BLOB in XDB$H_INDEX is below the minimum string
Reason for the Error
In the XDB$H_INDEX table, the CHILDREN column, a BLOB, must have a certain minimum length without being chained. The calculated length of the LOB was less than the stated minimum.
Solution
Set the value of the init.ora parameter db_block_size to at least 2K. For XDB to run at its fastest, set db_block_size to 8K.