hive表中允许的的最大列数

Question

有大神知道Apache hive中对每张表列数的限制吗？？
网上没有相关描述，官网也没找到。。。

Answer 1

I am not aware of any "hard" limitation in hive in regards to column count, there are some on column size though. This being said a restriction on column count would also probably depend on the file format, ORC having indexes and predicate pushdown does not behave as a Text file would. ORC has configurations for number of rows that are grouped together for an index.

In Hive issue: https://issues.apache.org/jira/browse/HIVE-7250 for example the number of columns > 1K created memory pressure in ORC resulting in OOM. In test 15K columns were loaded and saw OOM only at 20K columns.

参考这个链接
https://stackoverflow.com/questions/37368345/any-column-limits-in-hive