如何在R中中断RPostgresql查询 [英] How do I interrupt a RPostgresql query in R

问题描述

在RPostgresql中中断长时间运行的查询的最佳方法是什么?

What is the best way to interrupt a long-running query in RPostgresql?

例如，我想查看表的前10行并打算输入

For example, I wanted to see the first 10 rows of a table and meant to type,

  dbGetQuery(con,"
  select * from big.table
  limit 10
  ") 

但是有时我会忽略限制10"，然后我的程序将永远运行.从我的R终端中按ctrl-C或停止"按钮不起作用.我要么要等待很长时间，然后才能看到完整的打印输出，否则我可以中止R进程.

But I sometimes leave out the "limit 10" and then my program runs forever. Hitting ctrl-C or the stop button from my R terminal doesn't work. I either have to wait a long time and then see the full output print or I can abort the R process.

推荐答案

您可以尝试使用psql连接到Postgres，然后在select * from pg_stat_activity中查找查询，然后使用select pg_cancel_backend(long_query_pid)取消查询.

You can try to connect to Postgres with psql look for your query in select * from pg_stat_activity and then use select pg_cancel_backend(long_query_pid) to cancel the query.

或者您可以在R中使用此查询.

Or you can use this queries inside R.

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