SELECT opbel FROM sapsr3.dfkkop WHERE --mandt='200' and vkont='000802037649' ; runs in 5 ms. SELECT opbel FROM sapsr3.dfkkop WHERE mandt='200' and vkont='000802037649' ; runs in 15 s. (Factor 3.000) Column "mandt" has a cardinality of 2/1.000.000.000 (2 distinct values at 1 billion rows). Column vkont has a cardinality of 12.960.000/1.000.000.000. So I would expect to do the lookup on column vkont. Output of EXPLAIN: EXPLAIN SELECT opbel FROM sapsr3.dfkkop WHERE --mandt='200' and vkont='000802037649' ; mal ----------------------------------------------------------------------------------------------------------------------------------------------- function user.s11_3{autoCommit=true}(A0:str):void; X_3 := sql.mvc(); X_7 := sql.bind(X_3,"sapsr3","dfkkop","vkont",0); X_4:bat[:oid,:oid] := sql.tid(X_3,"sapsr3","dfkkop"); X_45 := algebra.subselect(X_7,X_4,A0,A0,true,true,false); (X_10,r1_10) := sql.bind(X_3,"sapsr3","dfkkop","vkont",2); X_46 := algebra.subselect(r1_10,A0,A0,true,true,false); X_13 := sql.bind(X_3,"sapsr3","dfkkop","vkont",1); X_47 := algebra.subselect(X_13,X_4,A0,A0,true,true,false); X_15 := sql.subdelta(X_45,X_4,X_10,X_46,X_47); X_17 := sql.bind(X_3,"sapsr3","dfkkop","opbel",0); (X_19,r1_22) := sql.bind(X_3,"sapsr3","dfkkop","opbel",2); X_21 := sql.bind(X_3,"sapsr3","dfkkop","opbel",1); X_22 := sql.projectdelta(X_15,X_17,X_19,r1_22,X_21); X_23 := sql.resultSet(1,1,X_22); sql.rsColumn(X_23,"sapsr3.dfkkop","opbel","varchar",12,0,X_22); X_28 := io.stdout(); sql.exportResult(X_28,X_23); end s11_3; # querylog.define("select\n opbel\nfrom\n sapsr3.dfkkop\nwhere\n --mandt=\\'200\\' and\n vkont=\\'000802037649\\';","default_pipe") # optimizer.mitosis() # optimizer.dataflow() EXPLAIN SELECT opbel FROM sapsr3.dfkkop WHERE mandt='200' and vkont='000802037649' ; mal ------------------------------------------------------------------------------------------------------------------------------------------------------ function user.s12_3{autoCommit=true}(A0:str,A1:str):void; X_4 := sql.mvc(); X_8 := sql.bind(X_4,"sapsr3","dfkkop","vkont",0); X_16 := sql.bind(X_4,"sapsr3","dfkkop","mandt",0); X_5:bat[:oid,:oid] := sql.tid(X_4,"sapsr3","dfkkop"); X_54 := algebra.subselect(X_16,X_5,A0,A0,true,true,false); (X_18,r1_21) := sql.bind(X_4,"sapsr3","dfkkop","mandt",2); X_55 := algebra.subselect(r1_21,A0,A0,true,true,false); X_20 := sql.bind(X_4,"sapsr3","dfkkop","mandt",1); X_56 := algebra.subselect(X_20,X_5,A0,A0,true,true,false); X_21 := sql.subdelta(X_54,X_5,X_18,X_55,X_56); X_57 := algebra.subselect(X_8,X_21,A1,A1,true,true,false); (X_11,r1_11) := sql.bind(X_4,"sapsr3","dfkkop","vkont",2); X_58 := algebra.subselect(r1_11,A1,A1,true,true,false); X_14 := sql.bind(X_4,"sapsr3","dfkkop","vkont",1); X_59 := algebra.subselect(X_14,X_21,A1,A1,true,true,false); X_23 := sql.subdelta(X_57,X_21,X_11,X_58,X_59); X_24 := sql.bind(X_4,"sapsr3","dfkkop","opbel",0); (X_26,r1_32) := sql.bind(X_4,"sapsr3","dfkkop","opbel",2); X_28 := sql.bind(X_4,"sapsr3","dfkkop","opbel",1); X_29 := sql.projectdelta(X_23,X_24,X_26,r1_32,X_28); X_30 := sql.resultSet(1,1,X_29); sql.rsColumn(X_30,"sapsr3.dfkkop","opbel","varchar",12,0,X_29); X_36 := io.stdout(); sql.exportResult(X_36,X_30); end s12_3; # querylog.define("explain\nselect\n opbel\nfrom\n sapsr3.dfkkop\nwhere\n mandt=\\'200\\' and\n vkont=\\'000802037649\\';","default_pipe") # optimizer.mitosis() # optimizer.dataflow()