Oracle Hybrid Columnar Compression(HCC) 混合列压缩

混合列压缩包含以下两种：

Migration and Best Practices

create table ... column store compress for query high;也可以使用一下方式：                    ... column store compress for query low.                    ... column store compress for archive low.                    ... column store compress for archive high.

alter table ... column store compress for query high;这种开启方式仅会对后续的dml操作进行压缩， 对于已经在表中的数据仍然是未压缩的。

Online Redefinition (DBMS_REDEFINITION)

alter table ... move column store compress for query high;

alter table ... move table/partition/subpartition ... online;