ORA-01450: maximum key length (6398) exceeded

Hello,

I'm trying to create new index on Table as below script:

CREATE INDEX ix_secure_pos01 ON SECURE_POS (extractValue(XMLRECORD,'/row/c2[position()=1]'),extractValue(XMLRECORD,'/row/c81[position()=1]'))

TABLESPACE INDX;

and the below error occurred:

ORA-01450: maximum key length (6398) exceeded

So I tried to create new table space with block size 16 as per below:

CREATE SMALLFILE TABLESPACE INDX_NEW DATAFILE

'/oradata/datafiles/INDX_NEW.DBF' SIZE 104857600 AUTOEXTEND ON NEXT 104857600 MAXSIZE 5368709120 BLOCKSIZE 16384 DEFAULT NOCOMPRESS ONLINE SEGMENT SPACE MANAGEMENT AUTO EXTENT MANAGEMENT LOCAL AUTOALLOCATE;

and below error occurred :

ORA-29339: tablespace block size 16384 does not match configured block sizes