https://communities.sas.com/t5/SAS-Procedures/proc-sql-where-clause/m-p/42176#M10929 Hi,<BR /> <BR /> Is threre a difference in performance between the two usage of where clause below? If yes which is more efficient?<BR /> <BR /> select a.*,b.* from table_a a(<WHERE clause="">) left join table_b on..<BR /> <BR /> <BR /> select a.*,b.* from table_a left join table_b on ... <WHERE clause=""><BR /> <BR /> Thanks!<BR /> Milton</WHERE></WHERE> Fri, 01 Apr 2011 08:30:30 GMT milts 2011-04-01T08:30:30Z https://communities.sas.com/t5/SAS-Procedures/proc-sql-where-clause/m-p/42176#M10929 Hi,<BR /> <BR /> Is threre a difference in performance between the two usage of where clause below? If yes which is more efficient?<BR /> <BR /> select a.*,b.* from table_a a(<WHERE clause="">) left join table_b on..<BR /> <BR /> <BR /> select a.*,b.* from table_a left join table_b on ... <WHERE clause=""><BR /> <BR /> Thanks!<BR /> Milton</WHERE></WHERE> Fri, 01 Apr 2011 08:30:30 GMT https://communities.sas.com/t5/SAS-Procedures/proc-sql-where-clause/m-p/42176#M10929 milts 2011-04-01T08:30:30Z https://communities.sas.com/t5/SAS-Procedures/proc-sql-where-clause/m-p/42177#M10930 the first is more efficient. Because it filter the data before the dataset loaded into PDV.<BR /> <BR /> <BR /> Ksharp Fri, 01 Apr 2011 10:26:42 GMT https://communities.sas.com/t5/SAS-Procedures/proc-sql-where-clause/m-p/42177#M10930 Ksharp 2011-04-01T10:26:42Z