I am seeing the following: select count(*) from f_sorted; +-----------+ | L7 | +===========+ | 102612097 | +-----------+ 1 tuple (0.988ms) select count(*) from f_sorted where yyyymm='201110'; +----------+ | L10 | +==========+ | 23505343 | +----------+ 1 tuple (1.0s) select count(distinct uuid) from f_sorted where yyyymm='201110'; +---------+ | L6 | +=========+ | 5941581 | +---------+ 1 tuple (23.8s) Very fast thus far! However: copy (select distinct(uuid) from f_sorted where yyyymm='201110') into '/home/user/filename' USING DELIMITERS ',','\n','"' NULL as 'null'; This has been running for hours and has yet to start writing to the file. I get this when I explain the query: +----------------------------------------------------------------------------------------+ | mal | +========================================================================================+ | function user.s5_3{autoCommit=true}():void; | | X_2 := sql.mvc(); | | X_22:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","yyyymm",0); | | X_23 := algebra.uselect(X_22,"201110":str); | | X_20:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","yyyymm",2); | | X_24 := algebra.kdifference(X_23,X_20); | | X_21 := algebra.uselect(X_20,"201110":str); | | X_25 := algebra.kunion(X_24,X_21); | | X_18:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","yyyymm",1); | | X_19 := algebra.uselect(X_18,"201110":str); | | X_26 := algebra.kunion(X_25,X_19); | | X_16:bat[:oid,:oid] := sql.bind_dbat(X_2,"sys","f_sorted",1); | | X_17 := bat.reverse(X_16); | | X_27 := algebra.kdifference(X_26,X_17); | | X_28 := algebra.markT(X_27,0@0:oid); | | X_29 := bat.reverse(X_28); | | X_10:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","uuid",0); | | X_8:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","uuid",2); | | X_12 := algebra.kdifference(X_10,X_8); | | X_13 := algebra.kunion(X_12,X_8); | | X_5:bat[:oid,:str] := sql.bind(X_2,"sys","f_sorted","uuid",1); | | X_14 := algebra.kunion(X_13,X_5); | | X_30 := algebra.leftjoin(X_29,X_14); | | (ext44,grp42) := group.done(X_30); | | X_33 := bat.mirror(ext44); | | X_34 := algebra.leftjoin(X_33,X_30); | | X_35 := sql.resultSet(1,1,X_34); | | sql.rsColumn(X_35,"sys.f_sorted","uuid":str,"varchar",2048,0,X_34); | | X_43 := io.stdout(); | | sql.exportResult(X_43,X_35); | | end s5_3; | +----------------------------------------------------------------------------------------+ 31 tuples (1.350ms) Is it doing something wrong? I don't expect the query to take so long (hours) to produce the output, especially since the distinct count is also very fast. The copy-into *seems* to be irrelevant to the problem, but I decided to include it just in case, as that's how I am using the query. -- View this message in context: http://old.nabble.com/select-distinct-...-where-algorithm-tp33297578p3329757... Sent from the monetdb-users mailing list archive at Nabble.com.