可以通过以下sql解决：
GRANT SELECT ON SCHEMA ustu TO usch;

查看是否开启

2.开启 INI 参数 GRANT_SCHEMA=1

SP_SET_PARA_VALUE(2,'GRANT_SCHEMA',1)

2.创建用户时，系统自动创建了同名模式USER01，USER02

CREATE USER USER01 IDENTIFIED BY 123456789; 
CREATE USER USER02 IDENTIFIED BY 123456789;

3.授予用户USER02建表，插入的权限

GRANT CREATE TABLE,INSERT TABLE TO USER02;

4.将模式USER02下所有对象的查询权限授予用户USER01

GRANT SELECT ON SCHEMA USER02 TO USER01;

5.登录用户USER02

CREATE TABLE T1(C1 INT); 
INSERT INTO T1 VALUES(1);
COMMIT;

6.登录用户USER01，可以查询成功

SELECT * FROM USER02.T1;

使用默认权限，例如：
ALTER DEFAULT PRIVILEGES FOR ROLE ustu IN SCHEMA ustu_schema
GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO usch;