Thanks Steve! Just want to get confirmation that postgres does not use any special rules When no sorting order specified. Thanks, Quang. On 5/30/14 5:20 PM, "Steve Atkins" <steve@xxxxxxxxxxx> wrote: > >On May 30, 2014, at 5:13 PM, Quang Thoi <Quang_Thoi@xxxxxxxxxxxx> wrote: > >> Any one knows how sorting works? >> >> I am using postgresql 9.3 and runs on Linux machines. >> I see different sorting order for the same set of return data. >> >> On linux machines, databases are configured the same. >> Database have encoding set to 'utf8' and locale='C' >> >> query: >> Select host_id, host_name from host_view order by host_id >> >> hos_id (character varying 128) >> host_name (character varying 255) >> >> - On one linux machine (locate in U.S) , the query returned following: >> >> host_id host_name >> ------------ ------------------ >> "00017486"; "lnx2.xx.yy.com" >> "00017486"; "lnx1.xx.yy.com" >> >> - On a different linux machine (locate in India), the query returned >>following: >> >> host_id host_name >> ------------ ------------------ >> "00017486"; "lnx1.xx.yy.com" >> "00017486"; "lnx2.xx.yy.com" > >Both results are correct. If you don't specify a sort order, postgresql >will return results in whatever order is convenient - which won't be >consistent from query to query or machine to machine. > >You're only sorting by host_id. If you want to sort consistently by >host_id and host_name, so that the sort order is well defined for >identical host_ids, you'll want to do something like > >select host_id, host_name from host_view order by host_id, host_name. > >Cheers, > Steve > >-- >Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) >To make changes to your subscription: >http://www.postgresql.org/mailpref/pgsql-general
