Odd/undocumented precedence of concatenation operator

Shay Rojansky <roji@roji.org> writes:

Trying to execute the following query on PostgreSQL 9.4.4:
select 'a' >= 'b' || 'c';
Gives the result "falsec", implying that the precedence of the string
concatenation operator is lower than the comparison operator. Changing the

= into = provides the result false, which is less surprising.

Is this the expected behavior, considering that >= and = behave differently
and that + ranks much higher?

It is expected, and documented. (It's also different in 9.5, see
http://git.postgresql.org/gitweb/?p=postgresql.git&amp;a=commitdiff&amp;h=c6b3c939b7e0f1d35f4ed4996e71420a993810d2)

If nothing else, it seems that the concatenation operator should be listed
on the operator precedence table at
http://www.postgresql.org/docs/9.4/static/sql-syntax-lexical.html#SQL-PRECEDENCE-TABLE

Both >= and || fall into the "any other operator" case, no?

regards, tom lane

--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

It is expected, and documented. (It's also different in 9.5, see

http://git.postgresql.org/gitweb/?p=postgresql.git&amp;a=commitdiff&amp;h=c6b3c939b7e0f1d35f4ed4996e71420a993810d2
)

Ah, thanks!

If nothing else, it seems that the concatenation operator should be

listed

on the operator precedence table at

http://www.postgresql.org/docs/9.4/static/sql-syntax-lexical.html#SQL-PRECEDENCE-TABLE

Both >= and || fall into the "any other operator" case, no?

I somehow missed that in the table, assuming that >= would be somewhere
with > and =. Thanks again.