PIG 如何计算别名中的行数 [英] PIG how to count a number of rows in alias
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问题描述
我做了这样的事情来计算 PIG 别名中的行数:
I did something like this to count the number of rows in an alias in PIG:
logs = LOAD 'log'
logs_w_one = foreach logs generate 1 as one;
logs_group = group logs_w_one all;
logs_count = foreach logs_group generate SUM(logs_w_one.one);
dump logs_count;
这似乎太低效了.如果有更好的方法请赐教!
This seems to be too inefficient. Please enlighten me if there is a better way!
推荐答案
COUNT is part of pig 查看手册
COUNT is part of pig see the manual
LOGS= LOAD 'log';
LOGS_GROUP= GROUP LOGS ALL;
LOG_COUNT = FOREACH LOGS_GROUP GENERATE COUNT(LOGS);
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