BUG #15611: pg_dump output changes after doing a restore with certain views - Mailing list pgsql-bugs

From PG Bug reporting form
Subject BUG #15611: pg_dump output changes after doing a restore with certain views
Date
Msg-id 15611-7efe329c2185c9b9@postgresql.org
Whole thread Raw
Responses Re: BUG #15611: pg_dump output changes after doing a restore with certain views
List pgsql-bugs
The following bug has been logged on the website:

Bug reference:      15611
Logged by:          Tessa Bradbury
Email address:      teresa.bradbury@bugcrowd.com
PostgreSQL version: 11.1
Operating system:   Alpine
Description:

When I do the following:

1. Create a view with a `foo IN (arglist)` clause in the target list
2. pg_dump
3. Restore from the dump
4. Run pg_dump again

The output of the two pg_dumps differs. The two versions represent the exact
same underlying structure but because it's not exactly the same I get
significant version control churn and it's hard to distinguish the real
changes from the noise. Because dumping and restoring is tedious, you can
also see this behaviour with pg_catalog.pg_get_viewdef().

## Reproduction steps ##

docker run --name test-postgres -d -p 5433:5432 postgres:11-alpine

cat << EOF | psql --echo-all -h 127.0.0.1 -p 5433 -U postgres
create table test_table (word character varying);
create view test_view as (select word IN ('apple', 'bannana') as fruit from
test_table);
-- the string that would be used in a pg_dump
select pg_catalog.pg_get_viewdef('test_view');
-- use that to create a new view, simulating a restore
create view test_view2 as (SELECT ((test_table.word)::text = ANY
((ARRAY['apple'::character varying, 'bannana'::character varying])::text[]))
AS fruit FROM test_table);
-- the string that would be used in the second pg_dump
select pg_catalog.pg_get_viewdef('test_view2');
EOF

## Expected behaviour ##

The output of both pg_catalog.pg_get_viewdef() calls is the same

## Actual behaviour ##

The output differs. The two versions are:

SELECT ((test_table.word)::text = ANY ((ARRAY['apple'::character varying,
'bannana'::character varying])::text[])) AS fruit FROM test_table
SELECT ((test_table.word)::text = ANY (ARRAY[('apple'::character
varying)::text, ('bannana'::character varying)::text])) AS fruit FROM
test_table


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