3310161 - Optimizer chooses ignores existing index when local variables are used as search arguments - SAP ASE

• Optimizer does not use an existing index when local variables are used, but it does use the index when the SARG is hardcoded
• the select statement contains a WHERE-CLAUSE with the 'LIKE' operator in the following form

          FirstName like @fname+'%' and LastName like @lname+'%' and  ..

• The query ignores using the appropriate index and takes longer to execute
• Trying to force the index causes a Forward Scan with Positioning at start of table.  

ASE 16.0

LIKE, slow query, drop, performance, local variable, tablescan, indexscan, "statement cache"  , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , Problem