The SUBSTRING64 function returns a variable-length character string of the large object column or variable parameter.
SUBSTRING64 supports searching LONG VARCHAR and LONG BINARY columns and LONG VARCHAR and LONG BINARY variables of any size of data. Currently, a SQL variable can hold up to 2GB - 1 in length.
If you are licensed to use the Unstructured Data Analytics functionality, you can use this function with large object data.
See SUBSTRING64 Function in Unstructured Data Analytics.