如何计算配置单元中一条记录的大小? [英] How to calculate size of the one record in hive?

问题描述

我需要了解我的表将使用多少内存.我知道记录的算术平均值.我知道有哪些类型的记录.但我无法理解如何计算记录的平均/最大大小.如果我获得每列记录的平均/最大大小，是否可以计算它?

I need to understand how much memory my table will use. I know the arithmetic mean of records. I know what types of records have. But I can't understand how to calculate mean/max size of the record. Is this possible to calculate it if I get mean/max size of every column of record?

推荐答案

获取每列的平均/最大大小

get mean/max size of every column

您还可以分析表格并获取列的统计信息.

Also you can analyze table and fetch stats for column.

分析表:

ANALYZE TABLE tablename COMPUTE STATISTICS FOR COLUMNS;

使用描述格式:

desc formatted  tablename  column_name

它将打印这些数字:

data_type, min, max, num_nulls, distinct_count, avg_col_len, max_col_len, num_trues, num_falses

不幸的是，它一次只适用于一列，您需要重复 describe 命令来获取所有列的统计信息.

Unfortunately, it works for single column at a time and you need to repeat describe command to get all columns stats.

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