PLSQL Developer查询结果表格中复制字段值，总会 卡顿一下，原因是PLSQL Dev默认会再次从oracle 数据字典里读取字段meta info，如图：
此功能大多数我们不需要，反而降低性能，影响使用感受。
可以在PL/SQL Dev中依次打开：
Configure->Preferences->Window Types->SQL Window
取消勾选“ Show dictionary info in result grid ”
关于该项在Manual中的解释如下：
Show dictionary info in result grid.
When enabled, the following dictionary info will be displayed in the result grid:
- The column data type, optionality, and comment will be displayed on the status line.
- A lookup list will be displayed for columns with a check constraint that checks for specific
values (e.g. col in (value1, value2, ...))
- A Lookup list will be displayed for columns with a foreign key constraint to small tables of
less than 1000 rows.