关于执行同步索引设置内存参数问题

SQL> execute pro_person;
BEGIN pro_person; END;*
ERROR at line 1:
ORA-20000: Oracle Text error:
DRG-10754: memory size must be between 1024 and 52428800
ORA-06512: at "CTXSYS.DRUE", line 157
ORA-06512: at "CTXSYS.CTX_DDL", line 1328
ORA-06512: at "test.PRO_PERSON", line 3
ORA-06512: at line 1存储过程里面是下面的同步索引
ctx_ddl.sync_index ('myindex', '100M');好像同步索引的内存不能超过50M，请问应该再哪调整？？？