Hi all,
Can someone explain me why this simple query takes so long to execute on MonetDB 5 server v11.17.13 "Jan2014-SP1"?
sql>select * from fp_tree limit 1; +-----------------------------+ | path | +=============================+ | ;8;60;379;519;1241;174;692; | +-----------------------------+ 1 tuple (1.2s)
Table fp_tree has one column path with data type string.
Some useful statistics of table fp_tree:
sql>select count(*) from fp_tree; +--------+ | L1 | +========+ | 416499 | +--------+ 1 tuple (2.801ms) sql>select max(length(path)) from fp_tree; +------+ | L1 | +======+ | 1275 | +------+ 1 tuple (254.742ms) sql>select min(length(path)) from fp_tree; +------+ | L1 | +======+ | 3 | +------+ 1 tuple (272.186ms) sql>select avg(length(path)) from fp_tree; +--------------------------+ | L1 | +==========================+ | 202.73579288305606 | +--------------------------+ 1 tuple (331.306ms)
Query trace:
+---------+-------------------------------------------------------------------+ | ticks | stmt | +=========+===================================================================+ | 3 | X_2 := sql.mvc(); | | 29 | X_35:bat[:oid,:oid] =<tmp_440>[104124] := sql.tid(X_2=0,"sys","fp | : : _tree",0,4); : | 6 | X_8=<tmp_3501>[0] := sql.bind(X_2=0,"sys","fp_tree","path",1); | | 40 | (X_52:bat[:oid,:oid] =<tmp_2110>[0],X_53:bat[:oid,:str] =<tmp_350 | : : 1>[0]) := sql.bind(X_2=0,"sys","fp_tree","path",2,3,4); : | 8 | X_45:bat[:oid,:str] =<tmp_1357>[104127] := sql.bind(X_2=0,"sys"," | : : fp_tree","path",0,3,4); : | 3 | X_57=<tmp_1357>[104127] := sql.delta(X_45=<tmp_1357>:bat[:oid,:st | : : r][104127],X_52=<tmp_2110>:bat[:oid,:oid][0],X_53=<tmp_3501>:bat[ : : : :oid,:str][0],X_8=<tmp_3501>[0]); : | 4 | X_41:bat[:oid,:oid] =<tmp_1256>[104127] := sql.tid(X_2=0,"sys","f | : : p_tree",3,4); : | 8 | X_61=<tmp_302>[104127] := algebra.leftfetchjoin(X_41=<tmp_1256>:b | : : at[:oid,:oid][104127],X_57=<tmp_1357>[104127]); : | 10 | X_65=<tmpr_1256>[1] := algebra.subslice(X_61=<tmp_302>[104127],0: | : : wrd,0:wrd); : | 6 | X_71=<tmp_1357>[1] := algebra.leftfetchjoin(X_65=<tmpr_1256>[1],X | : : _61=<tmp_302>[104127]); : | 1 | language.pass(X_61=<tmp_302>[104127]); | | 24 | (X_50:bat[:oid,:oid] =<tmp_2110>[0],X_51:bat[:oid,:str] =<tmp_350 | : : 1>[0]) := sql.bind(X_2=0,"sys","fp_tree","path",2,2,4); : | 5 | X_44:bat[:oid,:str] =<tmp_1560>[104124] := sql.bind(X_2=0,"sys"," | : : fp_tree","path",0,2,4); : | 3 | X_56=<tmp_1560>[104124] := sql.delta(X_44=<tmp_1560>:bat[:oid,:st | : : r][104124],X_50=<tmp_2110>:bat[:oid,:oid][0],X_51=<tmp_3501>:bat[ : : : :oid,:str][0]); : | 3 | X_39:bat[:oid,:oid] =<tmp_1760>[104124] := sql.tid(X_2=0,"sys","f | : : p_tree",2,4); : | 5 | X_60=<tmp_302>[104124] := algebra.leftfetchjoin(X_39=<tmp_1760>:b | : : at[:oid,:oid][104124],X_56=<tmp_1560>[104124]); : | 8 | X_64=<tmpr_1760>[1] := algebra.subslice(X_60=<tmp_302>[104124],0: | : : wrd,0:wrd); : | 4 | X_70=<tmp_1560>[1] := algebra.leftfetchjoin(X_64=<tmpr_1760>[1],X | : : _60=<tmp_302>[104124]); : | 1 | language.pass(X_60=<tmp_302>[104124]); | | 21 | (X_48:bat[:oid,:oid] =<tmp_2110>[0],X_49:bat[:oid,:str] =<tmp_350 | : : 1>[0]) := sql.bind(X_2=0,"sys","fp_tree","path",2,1,4); : | 5 | X_43:bat[:oid,:str] =<tmp_1660>[104124] := sql.bind(X_2=0,"sys"," | : : fp_tree","path",0,1,4); : | 1 | X_55=<tmp_1660>[104124] := sql.delta(X_43=<tmp_1660>:bat[:oid,:st | : : r][104124],X_48=<tmp_2110>:bat[:oid,:oid][0],X_49=<tmp_3501>:bat[ : : : :oid,:str][0]); : | 3 | X_37:bat[:oid,:oid] =<tmp_1054>[104124] := sql.tid(X_2=0,"sys","f | : : p_tree",1,4); : | 5 | X_59=<tmp_302>[104124] := algebra.leftfetchjoin(X_37=<tmp_1054>:b | : : at[:oid,:oid][104124],X_55=<tmp_1660>[104124]); : | 8 | X_63=<tmpr_1054>[1] := algebra.subslice(X_59=<tmp_302>[104124],0: | : : wrd,0:wrd); : | 5 | X_69=<tmp_1660>[1] := algebra.leftfetchjoin(X_63=<tmpr_1054>[1],X | : : _59=<tmp_302>[104124]); : | 1 | language.pass(X_59=<tmp_302>[104124]); | | 23 | (X_46:bat[:oid,:oid] =<tmp_2110>[0],X_47:bat[:oid,:str] =<tmp_350 | : : 1>[0]) := sql.bind(X_2=0,"sys","fp_tree","path",2,0,4); : | 9 | X_42:bat[:oid,:str] =<tmp_462>[104124] := sql.bind(X_2=0,"sys","f | : : p_tree","path",0,0,4); : | 2 | X_54=<tmp_462>[104124] := sql.delta(X_42=<tmp_462>:bat[:oid,:str] | : : [104124],X_46=<tmp_2110>:bat[:oid,:oid][0],X_47=<tmp_3501>:bat[:o : : : id,:str][0]); : | 6 | X_58=<tmp_764>[104124] := algebra.leftfetchjoin(X_35=<tmp_440>:ba | : : t[:oid,:oid][104124],X_54=<tmp_462>[104124]); : | 8 | X_62=<tmpr_440>[1] := algebra.subslice(X_58=<tmp_764>[104124],0:w | : : rd,0:wrd); : | 10 | X_72=<tmp_462>[1] := mat.packIncrement(X_62=<tmpr_440>[1],4); | | 3 | X_74=<tmp_462>[2] := mat.packIncrement(X_72=<tmp_462>[2],X_63=<tm | : : pr_1054>[1]); : | 1 | language.pass(X_63=<tmpr_1054>[1]); | | 2 | X_75=<tmp_462>[3] := mat.packIncrement(X_74=<tmp_462>[3],X_64=<tm | : : pr_1760>[1]); : | 1 | language.pass(X_64=<tmpr_1760>[1]); | | 3 | X_66=<tmp_462>[4] := mat.packIncrement(X_75=<tmp_462>[4],X_65=<tm | : : pr_1256>[1]); : | 1 | language.pass(X_65=<tmpr_1256>[1]); | | 9 | X_11=<tmpr_1206>[1] := algebra.subslice(X_66=<tmp_462>[4],0:wrd,0 | : : :wrd); : | 5 | X_68=<tmp_1760>[1] := algebra.leftfetchjoin(X_62=<tmpr_440>[1],X_ | : : 58=<tmp_764>[104124]); : | 1 | language.pass(X_62=<tmpr_440>[1]); | | 6 | language.pass(X_58=<tmp_764>[104124]); | | 1019824 | X_77=<tmp_1256>[1] := mat.packIncrement(X_68=<tmp_1760>[1],4); | | 8 | X_78=<tmp_1256>[2] := mat.packIncrement(X_77=<tmp_1256>[2],X_69=< | : : tmp_1660>[1]); : | 7 | X_79=<tmp_1256>[3] := mat.packIncrement(X_78=<tmp_1256>[3],X_70=< | : : tmp_1560>[1]); : | 18 | X_67=<tmp_1256>[4] := mat.packIncrement(X_79=<tmp_1256>[4],X_71=< | : : tmp_1357>[1]); : | 18 | X_12=<tmp_1357>[1] := algebra.leftfetchjoin(X_11=<tmpr_1206>[1],X | : : _67=<tmp_1256>[4]); : | 1095479 | barrier X_89 := language.dataflow(); | | 13 | X_13 := sql.resultSet(1,1,X_12=<tmp_1357>[1]); | | 7 | sql.rsColumn(X_13=7,"sys.fp_tree","path","clob",0,0,X_12=<tmp_135 | : : 7>[1]); : | 2 | X_17 := io.stdout(); | | 33 | sql.exportResult(X_17=="104d2":streams,X_13=7); | | 0 | end s2_2; | | 1095725 | function user.s2_2(); | | 1095772 | X_5:void := user.s2_2(); | +---------+-------------------------------------------------------------------+ 56 tuples (1.1s)
Why does mat.packIncrement takes so much time?
Thanks in advance,
Nik