The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/15/index.html
Description:
There is a bug in the documentation on the link
https://www.postgresql.org/docs/current/datatype-textsearch.html
postgres does not get stemmed to postgr by :to_tsquery( 'postgres:*' );
and
SELECT to_tsvector( 'postgraduate' ) @@ to_tsquery( 'postgres:*' );
returns f.
I am using PostgreSQL 12.14 but the documentation for PostgreSQL 12 is not
correct either.
Here is the output from my system:
SELECT to_tsvector( 'postgraduate' ), to_tsquery( 'postgres:*' );
to_tsvector | to_tsquery
------------------+--------------
'postgraduate':1 | 'postgres':*
(1 row)
So the below mentioned citation seems to be wrong.
Citation:
Note that to_tsquery will process prefixes in the same way as other words,
which means this comparison returns true:
SELECT to_tsvector( 'postgraduate' ) @@ to_tsquery( 'postgres:*' );
?column?
----------
t
because postgres gets stemmed to postgr:
SELECT to_tsvector( 'postgraduate' ), to_tsquery( 'postgres:*' );
to_tsvector | to_tsquery
---------------+------------
'postgradu':1 | 'postgr':*
which will match the stemmed form of postgraduate.