Oracle 21c

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select * from nls_session_parameters where parameter in ('NLS_LANGUAGE', 'NLS_SORT')

PARAMETER
VALUE

NLS_LANGUAGE
ENGLISH

NLS_SORT
BINARY

select greatest('á', 'b') from dual

GREATEST('Á','B')

á

alter session set nls_comp = 'linguistic'
alter session set nls_language = 'spanish'
select greatest('á', 'b') from dual

GREATEST('Á','B')

b