Problems with dump /restore of views

Started by Rod Taylorover 23 years ago3 messages
#1Rod Taylor
rbt@zort.ca

For some reason a view with a select distinct, an order and an exception
by will cause pg_dump to output a double order by -- one for each select
which of course is bad SQL.

PSQL
====
rbt_t=# create view test as select distinct relname, reltuples, relnatts
from pg_class where relkind = 't' except select relname, reltuples,
relnatts from pg_class where relkind = 't' and relnatts > 4 order by
relname;
CREATE

rbt_t=# select * from test;
relname | reltuples | relnatts
----------------+-----------+----------
pg_toast_1255 | 0 | 3
pg_toast_16384 | 0 | 3
pg_toast_16386 | 0 | 3
pg_toast_16408 | 0 | 3
pg_toast_16410 | 5 | 3
pg_toast_16416 | 0 | 3

PG_DUMP
=======
--
-- TOC Entry ID 2 (OID 337283)
--
-- Name: test Type: VIEW Owner: rbt
--

CREATE VIEW "test" as SELECT DISTINCT pg_class.relname,
pg_class.reltuples, pg_class.relnatts FROM pg_class WHERE
(pg_class.relkind = 't'::"char") ORDER BY pg_class.relname,
pg_class.reltuples, pg_class.relnatts EXCEPT SELECT pg_class.relname,
pg_class.reltuples, pg_class.relnatts FROM pg_class WHERE
((pg_class.relkind = 't'::"char") AND (pg_class.relnatts > 4)) ORDER BY
1;

PSQL
====
rbt_t=# drop view test;
DROP
rbt_t=# CREATE VIEW "test" as SELECT DISTINCT pg_class.relname,
pg_class.reltuples, pg_class.relnatts FROM pg_class WHERE
(pg_class.relkind = 't'::"char") ORDER BY pg_class.relname,
pg_class.reltuples, pg_class.relnatts EXCEPT SELECT pg_class.relname,
pg_class.reltuples, pg_class.relnatts FROM pg_class WHERE
((pg_class.relkind = 't'::"char") AND (pg_class.relnatts > 4)) ORDER BY
1;
ERROR: parser: parse error at or near "EXCEPT"

#2Jan Wieck
JanWieck@Yahoo.com
In reply to: Rod Taylor (#1)
Re: Problems with dump /restore of views

Rod Taylor wrote:

For some reason a view with a select distinct, an order and an exception
by will cause pg_dump to output a double order by -- one for each select
which of course is bad SQL.

I think views should not have ORDER BY clauses at all in the first
place.

Jan

--

#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
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#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: Rod Taylor (#1)
Re: Problems with dump /restore of views

Rod Taylor <rbt@zort.ca> writes:

For some reason a view with a select distinct, an order and an exception
by will cause pg_dump to output a double order by -- one for each select
which of course is bad SQL.

This is fixed in current sources and REL7_2 branch.

regards, tom lane