RMySQL，获取错误 - RS-DBI 驱动程序警告:(获取行时出错)

RMySQL, fetch errors - RS-DBI driver warning: (error while fetching rows)(RMySQL，获取错误 - RS-DBI 驱动程序警告:(获取行时出错))

问题描述

我正在使用 RMySQL 从数据表中获取一些行(表很大，所以我不能在这里发布它，但基本上包含一堆数字......总共 10 列和大约 12,000 行).运行 fetch(con, n=-1) 时出现以下错误:RS-DBI 驱动警告:(获取行时出错) 并且服务器仅返回 1713 行.

I am using RMySQL to fetch some rows from a data table (the table is large so I cannot post it here but basically contains a bunch of numbers.. a total of 10 columns and about 12,000 rows). I get the following error when I run fetch(con, n=-1): RS-DBI driver warning: (error while fetching rows) and the server returns only 1713 rows.

如果我摆脱了一些正在获取的列，那么这似乎可以正常工作.有谁知道这可能与什么有关?我什至不知道从哪里开始调试.这可能是服务器端设置吗?我的 R 会话有足够的内存(20 gigs).

If I get rid of some of the columns being fetched then this seems to work fine. Does anyone know what this can be related to? I don't even know where to start debugging. Could this be a server-side setting? My R session has more than enough memory (20 gigs).

推荐答案

每一列是一个数字，还是一个数字列表?也就是每列有多少字节?

Is each column a number, or a list of numbers? That is, how many bytes are in each column?

我以前遇到过这个问题，当我遇到它时，这是因为我试图太快地提取太多数据.我发现在这些情况下，有时可以使用较小的 n 值进行多次调用.再说一次，我遇到问题的数据库中的行很大

I've run into this problem before, and when I've hit it, it was because I was trying to pull too much data too fast. I've found that in those cases, making multiple calls with smaller values of n can sometimes work. Then again, the rows in the databases I've had trouble with have been huge

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