在Pig Latin中对各组进行总结

时间:2015-01-30 03:12:21

标签: hadoop apache-pig

我的数据行如下所示:

user    startTimestamp endTimestamp   durationForeground    application
11  1409239321000  1409239395000  1     IEXPLORE.EXE
11  1409239322000  0    19      IEXPLORE.EXE
11  1409239341000  0    18      IEXPLORE.EXE
11  1409239359000  0    0       IEXPLORE.EXE
11  1409239359000  0    7       IEXPLORE.EXE
11  1409239366000  0    6       IEXPLORE.EXE
11  1409239372000  0    10      IEXPLORE.EXE
11  1409239382000  0    13      IEXPLORE.EXE
11  1409239395000  1409239446000  9     MSPAINT.EXE
11  1409239404000  0    4       MSPAINT.EXE
11  1409239408000  0    13      MSPAINT.EXE
11  1409239421000  0    12      MSPAINT.EXE
11  1409239433000  0    5       MSPAINT.EXE
11  1409239438000  0    8       MSPAINT.EXE

我希望能够为每个小组加上所有durationForegrounds的总和;其中一个组以一个具有endTimestamp的行开始,并在下一次启动之前完成该行。

(原因是endTimestamp和startTimestamp之间的差异给我们app的运行时间,durationForeground的总和给我们应用程序在前台的时间。)

可以用Pig完成吗?

1 个答案:

答案 0 :(得分:2)

您可能需要选择userapplication对数据进行分组,并得到durationForeground的总和。

示例

<强>输入

11      1409239321000   1409239395000   1       IEXPLORE.EXE
11      1409239322000   0       19      IEXPLORE.EXE
11      1409239341000   0       18      IEXPLORE.EXE
11      1409239359000   0       0       IEXPLORE.EXE
11      1409239359000   0       7       IEXPLORE.EXE
11      1409239366000   0       6       IEXPLORE.EXE
11      1409239372000   0       10      IEXPLORE.EXE
11      1409239382000   0       13      IEXPLORE.EXE
11      1409239395000   1409239446000   9       MSPAINT.EXE
11      1409239404000   0       4       MSPAINT.EXE
11      1409239408000   0       13      MSPAINT.EXE
11      1409239421000   0       12      MSPAINT.EXE
11      1409239433000   0       5       MSPAINT.EXE
11      1409239438000   0       8       MSPAINT.EXE

<强> PigScript:

A = LOAD 'input' USING PigStorage() AS(user:int,startTimestamp:long,endTimestamp:long,durationForeground:long,application:chararray);
B = GROUP A BY (user,application);
C = FOREACH  B GENERATE FLATTEN(group),SUM(A.durationForeground);
DUMP C;

<强>输出:

(11,MSPAINT.EXE,51)
(11,IEXPLORE.EXE,74)

在上面的方法中,我假设所有输入字段都由制表符(\ t)分隔。