文档解释
ORA-44742: Cannot alter columns of a table that is shared by other group(s).
Cause: An attempt was made to add columns to, modify columns of, or drop columns from a table shared by other group(s).
Action: First drop group(s) with shared table(s) from this group and then proceed with this operation.
Oracle ORA-44742 错误表明您在更改表列时，此表已由其他组共享。
官方解释
ORA-44742 is an internal error code associated with an attempt to alter column of a table which is already being shared by other group(s).
常见案例
ORA-44742 错误通常发生在当您试图更改一个表的列时，此表（列）正由另一组共享。
一般处理方法及步骤
1.查看是否已共享表：确保表的确实共享给其他组。
2.禁用表的共享：如果确实存在共享表，则先禁用表的共享。
3.更改表列：更新表列之前，请确保没有执行操作。
4.重新启用表的共享：更新表列后，重新启用表的共享。
