GBase8a_MPP_Cluster-NoLicense-FREE 有限制吗

为提高效率，提问时请提供以下信息，问题描述清晰可优先响应。

【GBase版本】: GBase8a_MPP_Cluster-NoLicense-FREE-9.5.3.28.12

【操作系统】: redhat8-x86_64

【CPU】: intel

【问题描述】*: 不能新建主键，不能删除索引
DROP INDEX testdb.user_host_idx;
You have an error in your SQL syntax; check the manual that corresponds to your GBase server version for the right syntax to use near '.user_host_idx' at line 1

ALTER TABLE testdb.table1 ADD CONSTRAINT table1_pk PRIMARY KEY (name);
SQL 错误 [1702] [HY000]: gcluster table error: This version of GBase doesn't yet support 'ALTER column definition except increasing length of varchar'.