Re: Function's LEAST, GREATEST and DECODE (Oracle vararg polymorphic functions)
| От | Tom Lane |
|---|---|
| Тема | Re: Function's LEAST, GREATEST and DECODE (Oracle vararg polymorphic functions) |
| Дата | |
| Msg-id | 21609.1119580015@sss.pgh.pa.us обсуждение исходный текст |
| Ответ на | Function's LEAST, GREATEST and DECODE (Oracle vararg polymorphic functions) (Pavel Stehule <stehule@kix.fsv.cvut.cz>) |
| Ответы |
Re: Function's LEAST, GREATEST and DECODE (Oracle vararg
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| Список | pgsql-patches |
Pavel Stehule <stehule@kix.fsv.cvut.cz> writes: + /* If any argument is null, then result is null (for GREATEST and LEAST)*/ Are you sure about that? The only reference I could find says that these functions are not strict in Oracle: http://download-east.oracle.com/otn_hosted_doc/rdb/pdf/sql_ref_v71_vol1.pdf on page 2-185: The NULL keyword can appear in the list but is ignored. However, not all value expressions can be specified as NULL. That is, a non-NULL value expression must be in the list so that the data type for the expression can be determined. The GREATEST and LEAST functions can result in NULL only if at run time all value expressions result in NULL. The strict interpretation is mathematically cleaner, no doubt, but offhand it seems less useful. regards, tom lane
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