Replacing text inside blob

Question

I got quite large xml saved in BLOB and I need to edit value its value. I'm trying following

UPDATE MY_TABLE 
SET MY_BLOB=REPLACE(CONVERT(MY_BLOB USING UTF8), 'oldValue', 'newValue') 
WHERE MY_ID = 'someID'

Still, I keep getting SQL Error: ORA-00907: missing right parenthesis

but srsly, where do I miss something?

Answer 1

CONVERT needs a least two input parameters and is not for BLOB

Documentation

Here is useful information about update a text in BLOB column.

Answer 2

You can consider converting blob to clob and then calling replace function on it. Some useful info: http://fazlansabar.blogspot.com/2012/03/replace-function-for-blob-fields-in.html