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
