Hello, a) it is right, to place an ORDER BY at the end of the statement. That is the correct place to do this. but b) UNION doesn't mean anyway an sort. UNION mean "eliminate dups". But there are several techniques to do that. One of them is "sort". So, if the development crew chooses to change the elimination algorithme, that would be, in sight of an UNION, ok . Best wishes, Regards, Peter --------------------------------------------------------------------------- Peter Paefgen Landesamt für Datenverarbeitung und Statistik NRW. Telefon: 0211 9449 2390 Fax: 0211 9449 8390 Mail: peter.paefgen@xxxxxxxxxx -----Ursprüngliche Nachricht----- Von: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] Im Auftrag von Chris Mulcahy Gesendet: Donnerstag, 16. November 2006 00:53 An: George Pavlov Cc: Alexander Staubo; MicroUser; pgsql-general@xxxxxxxxxxxxxx Betreff: Re: [GENERAL] ORDER BY On Wed, 2006-11-15 at 14:59 -0800, George Pavlov wrote: Alas, this suggestion is wrong on two counts: (a) UNION expects a single > ORDER BY that applies to the whole recordset and which has to come at > the end; (b) UNION re-sorts anyway (it needs to eliminate the dupes) -- > maybe you are thinking UNION ALL? So, to follow your advice he may want > a query like this, although it seems quite silly and there still isn't > an ironclad guarantee re. the final result sorting: > > select * from > (select * from foo where name != 'Other' order by name) x union all > select * from foo where name = 'Other' > > Here ya go. select 1 SortCol, * from foo where name != 'Other' UNION ALL select 2 SortCol, * from foo where name = 'Other' order by SortCol; ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
