The column name appears in an aggregate function call select from rdb$collations order by 3, 2.Being able to order the results of a UNION
query using "field names" [CORE1505] #1920. Open.So you only use UNION ALL to avoid sorting if you know that there are no duplicate rows in the tables). Everything new in Firebird
SQL since InterBase 6. Paul Vinkenoog et al. ... Views can infer column names from derived tables or GROUP BY.