[PG-11] Potential bug related to INCLUDE clause of CREATE INDEX

[Aditya Toshniwal]

Hi Dave,

I am working on a feature to support INCLUDE clause of index in PG-11. As
per the documentation https://www.postgresql.org/docs/11/static/
sql-createindex.html, columns listed in INCLUDE clause cannot also be
present as index key columns. But I find different behaviour for below
queries which are logically identical.

CREATE TABLE some_table
(
    id serial primary key,
    first_name character varying(45),
    last_name character varying
)

CREATE INDEX ind1
    ON public.some_table USING btree
    (id)
    INCLUDE(id)
    TABLESPACE pg_default;

This query fails with error
ERROR: included columns must not intersect with key columns

CREATE INDEX ind1
    ON public.some_table USING btree
    (id asc nulls last)
    INCLUDE(id)
    TABLESPACE pg_default;

This query passes and index is created.

Kindly let me know if I am missing anything.

-- 
Thanks and Regards,
Aditya Toshniwal
Software Engineer | EnterpriseDB Software Solutions | Pune
"Don't Complain about Heat, Plant a tree"