select count(*) from table;

select count(*) from table; How does hive evaluate count(*) on a table? Does it return count by actually querying table, or directly return count by consulting some statistics locally. For Hive's Text format it takes few seconds while Hive's Orc format takes fraction of seconds. Regards, Amey

Re: select count(*) from table;

, Mar 22, 2016 at 12:44 PM, Amey Barve wrote: > select count(*) from table; > > How does hive evaluate count(*) on a table? > > Does it return count by actually querying table, or directly return count > by consulting some statistics locally. > > For Hive's Text form

Re: select count(*) from table;

adeh LinkedIn * https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw <https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* http://talebzadehmich.wordpress.com On 22 March 2016 at 07:14, Amey Barve wrote: > select count(*) from table; >

Re: select count(*) from table;

dOABUrV8Pw > <https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* > > > > http://talebzadehmich.wordpress.com > > > > On 22 March 2016 at 07:14, Amey Barve wrote: > >> select count(*) from table; >> >> How does hi

Re: select count(*) from table;

rely on those if needed >> >> >> HTH >> >> >> >> >> Dr Mich Talebzadeh >> >> >> >> LinkedIn * >> https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw >> <https://www.linkedin.com/profile/view?id=AA

Re: issue for the "select count(*) from table"

Hello, I think you might have loaded data by using an external tool into the table location; you should run: analyze table table1 compute statistics ; or analyze table table1 compute statistics for columns; And/or disable hive.optimize.metadataonly - but having bad statistics is not good at al