各位前辈：
1、varchar2类型是否比long类型的数据长呀？
2、binary_integer和pls_integer的区别在哪里呀？具体怎么使用呢？
有好的建议吗？
谢谢！

in 8i

Name  Code  Description  
CHAR  
96  
<= 2000-byte, fixed-length string  

NCHAR  
96  
<= 2000-byte, fixed-length single-byte or fixed-width multi-byte string  

DATE  
12  
7-byte, fixed-length date/time value  

LONG  
8  
<= 2147483647-byte, variable-length string  

LONG RAW  
24  
<= 2147483647-byte, variable-length binary data  

NUMBER  
2  
fixed or floating point number, represented in binary coded decimal format  

RAW  
23  
<= 255-byte, variable-length binary data  

ROWID  
11  
fixed-length binary value  

VARCHAR2  
1  
<= 4000-byte, variable-length string  

NVARCHAR2  
1  
<= 4000-byte, variable-length single-byte or fixed-width multi-byte string

BINARY_INTEGER
You use the BINARY_INTEGER datatype to store signed integers. Its magnitude range is -2147483647 .. 2147483647. Like PLS_INTEGER values, BINARY_INTEGER values require less storage than NUMBER values. However, most BINARY_INTEGER operations are slower than PLS_INTEGER operations.

PLS_INTEGER
You use the PLS_INTEGER datatype to store signed integers. Its magnitude range is -2147483647 .. 2147483647. PLS_INTEGER values require less storage than NUMBER values. Also, PLS_INTEGER operations use machine arithmetic, so they are faster than NUMBER and BINARY_INTEGER operations, which use library arithmetic. For better performance, use PLS_INTEGER for all calculations that fall within its magnitude range.

Although PLS_INTEGER and BINARY_INTEGER have the same magnitude range, they are not fully compatible. When a PLS_INTEGER calculation overflows, an exception is raised. However, when a BINARY_INTEGER calculation overflows, no exception is raised if the result is assigned to a NUMBER variable.

Because of this small semantic difference, you might want to continue using BINARY_INTEGER in old applications for compatibility. In new applications, always use PLS_INTEGER for better performance.

clearness!
Tks a lot
：〉