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|Reported by||Stephan Teeuwen|
Body of first available message related to this bug follows.
The following bug has been logged on the website: Bug reference: 16396 Logged by: Stephan Teeuwen Email address: (redacted) PostgreSQL version: 12.2 Operating system: Mac 10.15.3 Description: We recently upgraded from PG 9.5 to PG 12.2 and encountered the following error message: "ERROR: UNION types integer and text cannot be matched" Even though docs state that if the left side of the join is defined. the right side type should not have been defined: https://www.postgresql.org/docs/12/typeconv-union-case.html This query fits the documented on above url: SELECT CAST(NULL AS INTEGER) AS hello_world UNION SELECT NULL AS hello_world But as in our query the following happened: SELECT hello_world FROM (SELECT CAST(NULL AS INTEGER) AS hello_world) as a UNION SELECT hello_world FROM (SELECT NULL AS hello_world) as b It fails and is only fixable by defining the NULL in the right side of the UNION as CAST(NULL AS INTEGER) Which wasn't required on Postgres 9.5, but is required for sure on Postgres 12.2 I'm unsure which version introduced this different, but it would be good to have it represented in the documentation mentioned above! King regards, Stephan Teeuwen
|2020-04-27 15:26:59+00||PG Bug reporting form||BUG #16396: Parallel Union queries seem to treat NULL values differently|
|2020-04-27 15:57:35+00||"David G(dot) Johnston"||Re: BUG #16396: Parallel Union queries seem to treat NULL values differently|
|2020-04-27 16:40:52+00||Tom Lane||Re: BUG #16396: Parallel Union queries seem to treat NULL values differently|