Yes, You will have to update in database as well.
UPDATE metadatavalue
SET text_value = REPLACE(text_value, '
http://abc.com', '
http://xyz.com')
WHERE metadata_field_id = (
SELECT metadata_field_id
FROM metadatafieldregistry
WHERE element = 'identifier' AND qualifier = 'uri'
);
and then
./dspace index-discovery (in [dspace]/bin )