那些遇到过的问题

MonetDB-为什么加倍的自连接会导致查询执行时间从几毫秒到几小时不等？

Fop*_*tin 5 database performance join self-join monetdb

我SQL在非常简单的表上运行查询.这些表使用此处介绍的"垂直分区"对RDF图进行建模.因此,它们都具有以下模型,其中s是"主体"并且o是对象.

CREATE TABLE a_table (BIGINT s, BIGINT o)
Run Code Online (Sandbox Code Playgroud)

鉴于我449669在表中有元组存储prop_eventPrecedeInTask.运行了以下查询(在表上有4个自联接prop_eventPrecedeInTask)353 ms 

SELECT t1.s AS event1, t2.o AS event2, t3.o AS event3, 
       t4.o AS event4, t5.o AS event5, t6.o AS event6 
FROM "prop_SystemCallIsExecutedDuringTask" t1,
     "prop_eventPrecedeInTask" t2,
     "prop_eventPrecedeInTask" t3,
     "prop_eventPrecedeInTask" t4,
     "prop_eventPrecedeInTask" t5,
     "prop_eventPrecedeInTask" t6          
WHERE t1.o = 15667
  AND t1.s = t2.s 
  AND t2.o = t3.s
  AND t3.o = t4.s
  AND t4.o = t5.s
  AND t5.o = t6.s;
Run Code Online (Sandbox Code Playgroud)

但是,当我将同一个表上的自联接数量增加一倍时(使用9个自联接),查询在一小时后没有完成. 

SELECT t1.s AS event1, t2.o AS event2, t3.o AS event3, 
       t4.o AS event4, t5.o AS event5, t6.o AS event6, 
       t7.o AS event7, t8.o AS event8, t9.o AS event9, 
       t10.o AS event10, t11.o AS event11 
FROM "prop_SystemCallIsExecutedDuringTask" t1,
     "prop_eventPrecedeInTask" t2,
     "prop_eventPrecedeInTask" t3,
     "prop_eventPrecedeInTask" t4,
     "prop_eventPrecedeInTask" t5,
     "prop_eventPrecedeInTask" t6,
     "prop_eventPrecedeInTask" t7,
     "prop_eventPrecedeInTask" t8,
     "prop_eventPrecedeInTask" t9,
     "prop_eventPrecedeInTask" t10,
     "prop_eventPrecedeInTask" t11 
WHERE t1.o = 15667
  AND t1.s = t2.s 
  AND t2.o = t3.s
  AND t3.o = t4.s
  AND t4.o = t5.s
  AND t5.o = t6.s
  AND t6.o = t7.s
  AND t7.o = t8.s
  AND t8.o = t9.s
  AND t9.o = t10.s
  AND t10.o = t11.s;
Run Code Online (Sandbox Code Playgroud)

表演中对drawbak的解释是什么？我可以改进查询吗？

组态

我的工作Ubuntu 12.0.4,以MonetDB Database Server v1.7 (Jan2014)对内存的机器的64G.

在小型数据集上添加查询的查询执行跟踪(TRACE SELECT ...)

+-------+------------------------------------------------------------------------------------------------------------+
| ticks | stmt                                                                                                           |
+=======+================================================================= ===========================================+
|    16 | X_3 := sql.mvc();                                                                                              |
|    28 | X_7=<tmp_1326>[3939] := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","o",0);                     |
|    36 | (X_59=<tmp_21>[0],r1_129=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",2);            |
|    20 | X_72=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",1);                                 |
|    13 | X_62=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",1);                                 |
|    30 | X_55:bat[:oid,:oid] =<tmp_17710>[78450] := sql.tid(X_3=0,"sys","prop_eventPrecedeInTask");                 |
|    16 | X_37=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",1);                                 |
|    16 | (X_34=<tmp_21>[0],r1_40=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",2);             |
|    14 | X_32=<tmp_2063>[78450] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",0);                           |
|    15 | X_28=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",1);                                 |
|    13 | (X_26=<tmp_21>[0],r1_31=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",2);             |
|    13 | X_25=<tmp_2055>[78450] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",0);                          |
|    21 | X_23:bat[:oid,:oid] =<tmp_25746>[78450] := sql.tid(X_3=0,"sys","prop_eventPrecedeInTask");                 |
|    30 | X_29=<tmp_33332>[78450] := sql.projectdelta(X_23=<tmp_25746>:bat[:oid,:oid][78450],X_25=<tmp_2055>[78450], 
| 
:       : X_26=<tmp_21>[0],r1_31=<tmp_33>[0],X_28=<tmp_33>[0]);                                                      :
|    21 | (X_69=<tmp_21>[0],r1_140=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",2);            |
|    21 | X_21=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","s",1);                     |
|    14 | (X_19=<tmp_21>[0],r1_22=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","s",2); |
|    12 | X_17=<tmp_1320>[3939] := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","s",0);                |
|    11 | X_13=<tmp_33>[0] := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","o",1);                     |
|    20 | (X_10=<tmp_21>[0],r1_10=<tmp_33>[0]) := sql.bind(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask","o",2); |
|    24 | X_149=<tmp_34471>[0] := algebra.subselect(r1_10=<tmp_33>    [0],A0=15667:lng,A0=15667:lng,true,true,false);    |
|    18 | X_4:bat[:oid,:oid] =<tmp_4731>[3939] := sql.tid(X_3=0,"sys","prop_SystemCallIsExecutedDuringTask");        |
|   113 | X_148=<tmp_21746>[0] := algebra.subselect(X_7=<tmp_1326>[3939],X_4=<tmp_4731>:bat[:oid,:oid][3939],A0=1566 |
:       : 7:lng,A0=15667:lng,true,true,false);                                                                       :
|    24 | X_150=<tmp_6675>[0] := algebra.subselect(X_13=<tmp_33>[0],X_4=<tmp_4731>:bat[:oid,:oid][3939],A0=15667:lng |
:       : ,A0=15667:lng,true,true,false);                                                                            :
|    27 | X_38=<tmp_32620>[78450] := sql.projectdelta(X_23=<tmp_25746>:bat[:oid,:oid][78450],X_32=<tmp_2063>[78450], |
:       : X_34=<tmp_21>[0],r1_40=<tmp_33>[0],X_37=<tmp_33>[0]);                                                      :
|     8 | language.pass(X_23=<tmp_25746>:bat[:oid,:oid][78450]);                                                     |
|    15 | X_56=<tmp_2055>[78450] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","s",0);                           |
|    31 | X_65=<tmp_33344>[78450] := sql.projectdelta(X_55=<tmp_17710>:bat[:oid,:oid][78450],X_56=<tmp_2055>[78450], |
:       : X_59=<tmp_21>[0],r1_129=<tmp_33>[0],X_62=<tmp_33>[0]);                                                     :
|    17 | X_68=<tmp_2063>[78450] := sql.bind(X_3=0,"sys","prop_eventPrecedeInTask","o",0);                           |
|    11 | X_15=<tmp_21746>[0] := sql.subdelta(X_148=<tmp_21746>[0],X_4=<tmp_4731>:bat[:oid,:oid][3939],X_10=<tmp_21> |
:       : [0],X_149=<tmp_34471>[0],X_150=<tmp_6675>[0]);                                                             :
|    13 | language.pass(X_4=<tmp_4731>:bat[:oid,:oid][3939]);                                                        |
|    43 | X_22=<tmp_25746>[0] := sql.projectdelta(X_15=<tmp_21746>[0],X_17=<tmp_1320>[3939],X_19=<tmp_21>[0],r1_22=< |
:       : tmp_33>[0],X_21=<tmp_33>[0]);                                                                              :
|    33 | (X_30=<tmp_21746>[0],r1_36=<tmp_12754>[0]) := algebra.join(X_22=<tmp_25746>[0],X_29=<tmp_33332>[78450]);   |
|    38 | X_39=<tmp_23566>[0] := algebra.leftfetchjoin(r1_36=<tmp_12754>[0],X_38=<tmp_32620>[78450]);                |
|    28 | (X_40=<tmp_12754>[0],r1_58=<tmp_4661>[0]) := algebra.join(X_39=<tmp_23566>[0],X_29=<tmp_33332>[78450]);    |
|    29 | X_42=<tmp_10412>[0] := algebra.leftfetchjoin(r1_58=<tmp_4661>[0],X_38=<tmp_32620>[78450]);                 |
|    18 | (X_43=<tmp_4661>[0],r1_76=<tmp_4056>[0]) := algebra.join(X_42=<tmp_10412>[0],X_29=<tmp_33332>[78450]);     |
|    18 | X_45=<tmp_11601>[0] := algebra.leftfetchjoin(r1_76=<tmp_4056>[0],X_38=<tmp_32620>[78450]);                 |
|    14 | (X_46=<tmp_4056>[0],r1_97=<tmp_14043>[0]) := algebra.join(X_45=<tmp_11601>[0],X_29=<tmp_33332>[78450]);    |
|    26 | X_73=<tmp_33524>[78450] := sql.projectdelta(X_55=<tmp_17710>:bat[:oid,:oid][78450],X_68=<tmp_2063>[78450], |
:       : X_69=<tmp_21>[0],r1_140=<tmp_33>[0],X_72=<tmp_33>[0]);                                                     :
|    10 | language.pass(X_55=<tmp_17710>:bat[:oid,:oid][78450]);                                                     |
|  9434 | X_49=<tmp_13521>[0] := algebra.leftfetchjoin(r1_97=<tmp_14043>[0],X_38=<tmp_32620>[78450]);                |
|    47 | (X_51=<tmp_14043>[0],r1_115=<tmp_36607>[0]) := algebra.join(X_49=<tmp_13521>[0],X_29=<tmp_33332>[78450]);  |
|     6 | language.pass(X_29=<tmp_33332>[78450]);                                                                    |
|    23 | X_54=<tmp_33332>[0] := algebra.leftfetchjoin(r1_115=<tmp_36607>[0],X_38=<tmp_32620>[78450]);               |
|     7 | language.pass(X_38=<tmp_32620>[78450]);                                                                    |
|    30 | (X_66=<tmp_4731>[0],r1_137=<tmp_6675>[0]) := algebra.join(X_54=<tmp_33332>[0],X_65=<tmp_33344>[78450]);    |
|    19 | X_74=<tmp_34471>[0] := algebra.leftfetchjoin(r1_137=<tmp_6675>[0],X_73=<tmp_33524>[78450]);                |
|    17 | (X_75=<tmp_6675>[0],r1_154=<tmp_4677>[0]) := algebra.join(X_74=<tmp_34471>[0],X_65=<tmp_33344>[78450]);    |
|    14 | X_77=<tmp_11503>[0] := algebra.leftfetchjoin(r1_154=<tmp_4677>[0],X_73=<tmp_33524>[78450]);                |
|    13 | (X_78=<tmp_4677>[0],r1_176=<tmp_6501>[0]) := algebra.join(X_77=<tmp_11503>[0],X_65=<tmp_33344>[78450]);    |
|    15 | X_80=<tmp_24055>[0] := algebra.leftfetchjoin(r1_176=<tmp_6501>[0],X_73=<tmp_33524>[78450]);                |
|    14 | (X_81=<tmp_6501>[0],r1_193=<tmp_7616>[0]) := algebra.join(X_80=<tmp_24055>[0],X_65=<tmp_33344>[78450]);    |
|    16 | X_83=<tmp_25373>[0] := algebra.leftfetchjoin(r1_193=<tmp_7616>[0],X_73=<tmp_33524>[78450]);                |
|    29 | (X_84=<tmp_7616>[0],r1_216=<tmp_7215>[0]) := algebra.join(X_83=<tmp_25373>[0],X_65=<tmp_33344>[78450]);    |
|     7 | language.pass(X_65=<tmp_33344>[78450]);                                                                    |
|    67 | X_98=<tmp_17710>[0] := algebra.leftfetchjoin(r1_216=<tmp_7215>[0],X_73=<tmp_33524>[78450]);                |
|     2 | language.pass(X_73=<tmp_33524>[78450]);                                                                    |
|  1129 | X_151=<tmp_26246>[0] := algebra.leftfetchjoin(X_84=<tmp_7616>[0],X_81=<tmp_6501>[0]);                      |
|    85 | X_86:bat[:oid,:lng] =<tmp_6501>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X_ |
:       : 75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_51=<tmp_14043>[0],X_46=<tmp_4056>[0],X_43=<tmp_4661>[0],X_40=<tmp_12 :
:       : 754>[0],X_30=<tmp_21746>[0],X_22=<tmp_25746>[0]);                                                          :
|    67 | X_95=<tmp_32620>[0] := algebra.leftfetchjoin(X_84=<tmp_7616>[0],X_83=<tmp_25373>[0]);                      |
|     3 | language.pass(X_84=<tmp_7616>[0]);                                                                         |
|     2 | language.pass(X_83=<tmp_25373>[0]);                                                                        |
|    14 | X_89:bat[:oid,:lng] =<tmp_7616>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X_ |
:       : 75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_51=<tmp_14043>[0],X_46=<tmp_4056>[0],X_45=<tmp_11601>[0]);           :
|     2 | language.pass(X_45=<tmp_11601>[0]);                                                                        |
|    79 | X_87:bat[:oid,:lng] =<tmp_10432>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X |
:       : _75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_51=<tmp_14043>[0],X_46=<tmp_4056>[0],X_43=<tmp_4661>[0],X_40=<tmp_1 :
:       : 2754>[0],X_39=<tmp_23566>[0]);                                                                             :
|     2 | language.pass(X_40=<tmp_12754>[0]);                                                                        |
|     7 | language.pass(X_22=<tmp_25746>[0]);                                                                        |
|  6902 | X_88:bat[:oid,:lng] =<tmp_33524>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X |
:       : _75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_51=<tmp_14043>[0],X_46=<tmp_4056>[0],X_43=<tmp_4661>[0],X_42=<tmp_1 :
:       : 0412>[0]);                                                                                                 :
|     2 | language.pass(X_46=<tmp_4056>[0]);                                                                         |
| 27091 | X_90:bat[:oid,:lng] =<tmp_11601>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X |
:       : _75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_51=<tmp_14043>[0],X_49=<tmp_13521>[0]);                             :
|     5 | language.pass(X_43=<tmp_4661>[0]);                                                                         |
|     3 | language.pass(X_51=<tmp_14043>[0]);                                                                        |
|     2 | language.pass(X_49=<tmp_13521>[0]);                                                                        |
|    26 | X_91:bat[:oid,:lng] =<tmp_25746>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X |
:       : _75=<tmp_6675>[0],X_66=<tmp_4731>[0],X_54=<tmp_33332>[0]);                                                 :
|    24 | X_92:bat[:oid,:lng] =<tmp_13521>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X |
:       : _75=<tmp_6675>[0],X_74=<tmp_34471>[0]);                                                                    :
|     2 | language.pass(X_75=<tmp_6675>[0]);                                                                         |
|     1 | language.pass(X_54=<tmp_33332>[0]);                                                                        |
|    10 | X_93:bat[:oid,:lng] =<tmp_6675>[0] := algebra.leftfetchjoinPath(X_151=<tmp_26246>[0],X_78=<tmp_4677>[0],X_ |
:       : 77=<tmp_11503>[0]);                                                                                        :
|     1 | language.pass(X_78=<tmp_4677>[0]);                                                                         |
|     1 | language.pass(X_74=<tmp_34471>[0]);                                                                        |
|     7 | X_94:bat[:oid,:lng] =<tmp_34471>[0] := algebra.leftfetchjoin(X_151=<tmp_26246>[0],X_80=<tmp_24055>[0]);    |
|     1 | language.pass(X_151=<tmp_26246>[0]);                                                                       |
|     2 | language.pass(X_77=<tmp_11503>[0]);                                                                        |
|     2 | language.pass(X_80=<tmp_24055>[0]);                                                                        |
|     9 | language.pass(X_42=<tmp_10412>[0]);                                                                        |
|     3 | language.pass(X_66=<tmp_4731>[0]);                                                                         |
|     4 | language.pass(X_39=<tmp_23566>[0]);                                                                        |
| 65664 | barrier X_178 := language.dataflow();                                                                      |
|     9 | X_99 := sql.resultSet(11,1,X_86=<tmp_6501>:bat[:oid,:lng][0]);                                             |
|     6 | sql.rsColumn(X_99=4,"sys.L","event1","bigint",64,0,X_86=<tmp_6501>:bat[:oid,:lng][0]);                     |
|     4 | sql.rsColumn(X_99=4,"sys.L","event2","bigint",64,0,X_87=<tmp_10432>:bat[:oid,:lng][0]);                    |
|     4 | sql.rsColumn(X_99=4,"sys.L","event3","bigint",64,0,X_88=<tmp_33524>:bat[:oid,:lng][0]);                    |
|     3 | sql.rsColumn(X_99=4,"sys.L","event4","bigint",64,0,X_89=<tmp_7616>:bat[:oid,:lng][0]);                     |
|     3 | sql.rsColumn(X_99=4,"sys.L","event5","bigint",64,0,X_90=<tmp_11601>:bat[:oid,:lng][0]);                    |
|     3 | sql.rsColumn(X_99=4,"sys.L","event6","bigint",64,0,X_91=<tmp_25746>:bat[:oid,:lng][0]);                    |
|     2 | sql.rsColumn(X_99=4,"sys.L","event7","bigint",64,0,X_92=<tmp_13521>:bat[:oid,:lng][0]);                    |
|     3 | sql.rsColumn(X_99=4,"sys.L","event8","bigint",64,0,X_93=<tmp_6675>:bat[:oid,:lng][0]);                     |
|     5 | sql.rsColumn(X_99=4,"sys.L","event9","bigint",64,0,X_94=<tmp_34471>:bat[:oid,:lng][0]);                    |
|     5 | sql.rsColumn(X_99=4,"sys.L","event10","bigint",64,0,X_95=<tmp_32620>[0]);                                  |
|     5 | sql.rsColumn(X_99=4,"sys.L","event11","bigint",64,0,X_98=<tmp_17710>[0]);                                  |
|     2 | X_127 := io.stdout();                                                                                      |
|    30 | sql.exportResult(X_127=="104d2":streams,X_99=4);                                                           |
|     1 | end s3_3;                                                                                                  |
| 66047 | function user.s3_3(A0=15667:lng);                                                                          |
| 66145 | X_5:void  := user.s3_3(15667:lng);                                                                         |
+-------+------------------------------------------------------------------------------------------------------------+
Run Code Online (Sandbox Code Playgroud)

编辑2 变形例的元组类型的从INT至BIGINT

归档时间：

查看次数：

217 次

最近记录：

11 年 前
相关归档
多线程是否会提高单处理器的计算速度 21
在捕获异常时是否有理由不使用final关键字？ 21
按另一个表选择每个行连接的最小值 15
如何存储多年值100 x 25 Hz的时间序列--Sql Server或timeseries数据库 9
你如何在python中使用数组执行os.path.join？ 9
ActivityRecord的活动空闲超时 9
成员初始化列表真的更有效吗？ 7
SQL Server 2008,加入还是不加入？ 6
在SQL语句中使用LIMIT时,性能提高了多少？ 6
根据相同的ID从两个表中选择所有内容 1
难疑归档
使用Git版本控制查看文件的更改历史记录 2920
在字典中添加新密钥？ 2427
在JavaScript中验证十进制数 - IsNumeric() 2318
迭代对象属性 1904
配置错误:此配置部分不能在此路径中使用 1694
从HTML页面重定向 1523
插入...值(SELECT ... FROM ...) 1340
丢弃Git中的本地提交 1304
在jQuery中序列化为JSON 1189
Access-Control-Allow-Origin标头如何工作？ 1050