01 package util;
02 
03 import java.sql.*;
04 import javax.naming.*;
05 import javax.sql.*;
06 
07 import org.apache.commons.dbcp.BasicDataSource;
08 
09 public class DBConnect {
10   static DataSource dataSource = null;
11 
12   public static DataSource setupDataSource( String sDrvName, String sUserName,
13       String sPwd, String connectURI ) {
14       BasicDataSource ds = new BasicDataSource();
15       ds.setDriverClassName( sDrvName );
16       ds.setUsername( sUserName );
17       ds.setPassword( sPwd );
18       ds.setUrl( connectURI );
19       ds.setMaxActive( 50 );
20       ds.setMaxIdle( 10 );
21       ds.setMaxWait( 10000 ); // 10 seconds
22       return ds;
23   }
24 
25 
26   // static init of the class
27   static {
28     try {
29       System.setProperty( "jdbc.drivers", "oracle.jdbc.driver.OracleDriver" );
30       Class.forName( "oracle.jdbc.driver.OracleDriver" );
31 
32       dataSource = setupDataSource( "oracle.jdbc.driver.OracleDriver", "username",
33         "password", "jdbc:oracle:thin:@192.168.0.1:1521:SID" );
34     }
35     catch (Exception e) {
36       System.out.println( "DBConnect.java => Unable to load driver."  + e.getMessage() );
37     }
38   }
39 
40   /**
41    * 空的建構元，不作任何處理動作。
42    */
43   public DBConnect() {}
44 
45   /**
46    * 取得 DB Connection.
47    */
48   public static Connection getConnection() throws SQLException,ClassNotFoundException {
49     BasicDataSource bds = (BasicDataSource) dataSource;
50     System.out.println("NumActive: " + bds.getNumActive() + ","
51       + "NumIdle: " + bds.getNumIdle() );
52     return dataSource.getConnection();
53   }
54 }

Create Table Test(
c1 int not null,
c2 money default 0,
c3 varchar(20),
constraint PK_Test primary key(c1))
go

create index ind_c2_Test on Test(c2)
go

插入一些数据后，我们可以测试如下：
1> set showplan on
2> go
1> declare @var_int int
2> select @var_int=2
3> select * from Test where c1=@var_int
4> go

QUERY PLAN FOR STATEMENT 1 (at line 1).

    STEP 1
        The type of query is DECLARE.

QUERY PLAN FOR STATEMENT 2 (at line 2).

    STEP 1
        The type of query is SELECT.

QUERY PLAN FOR STATEMENT 3 (at line 3).

    STEP 1
        The type of query is SELECT.

        FROM TABLE
            Test
        Nested iteration.
        Using Clustered Index.
        Index : PK_Test
        Forward scan.
        Positioning by key.
        Keys are:
            c1  ASC
        Using I/O Size 2 Kbytes for data pages.
        With LRU Buffer Replacement Strategy for data pages.

(1 row affected)
 c1          c2                       c3
 ----------- ------------------------ --------------------
           2                   129.14 Hellen

(1 row affected)
我们看到，sybase的执行计划会使用clustered index来读取数据。

下面，采用money类型来进行测试
1> declare @var_money money
2> select @var_money=2
3> select * from Test where c1=@var_money
4> go

QUERY PLAN FOR STATEMENT 1 (at line 1).

    STEP 1
        The type of query is DECLARE.

QUERY PLAN FOR STATEMENT 2 (at line 2).

    STEP 1
        The type of query is SELECT.

QUERY PLAN FOR STATEMENT 3 (at line 3).

    STEP 1
        The type of query is SELECT.

        FROM TABLE
            Test
        Nested iteration.
        Table Scan.
        Forward scan.
        Positioning at start of table.
        Using I/O Size 2 Kbytes for data pages.
        With LRU Buffer Replacement Strategy for data pages.

(1 row affected)
 c1          c2                       c3
 ----------- ------------------------ --------------------
           2                   129.14 Hellen

(1 row affected)

我们可以看到，sybase没有采用索引，而是采用了全表扫描。

实际上，Sybase并不是类型不一致就一定不会使用索引，而是有一个匹配原则，原则上是只要索引列的类型优先级高于搜索条件的数据类型，就会使用索引。
这个优先级，可以通过查询系统表master.dbo.systypes.
1> select hierarchy,name from master.dbo.systypes
2> order by 1
3> go
 hierarchy name
 --------- ------------------------------
         1 floatn
         2 float
         3 datetimn
         4 datetime
         5 real
         6 numericn
         7 numeric
         8 decimaln
         9 decimal
        10 moneyn
        11 money
        12 smallmoney
        13 smalldatetime
        14 intn
        15 int
        16 smallint
        17 tinyint
        18 bit
        19 univarchar
        20 unichar
        22 sysname
        22 varchar
        22 nvarchar
        23 char
        23 nchar
        24 timestamp
        24 varbinary
        25 binary
        26 text
        27 image
        99 extended type

对方的msn messenger会发现你有头像信息，会通过SS向你发送msn p2p的invite msnmsng请求。然后你回应，传送头像二进制流。就是一个p2p通讯的过程。
目前，还在研究中。发现，每个p2p消息中，都包含了一个48字节的一个头。至于是什么内容，今天刚刚得到一位朋友的指点。
1.  This is a DWORD and contains the SessionID, which is zero when the Clients are negotiating  about the session. This field is only used when actually sending data (DP’s, CE’s etc). The  value of this field in Ink messages is always 64!

2.  This field is again a DWord, which identifies the message (the so called Base Identifier). In  Ink this field has the same value in all messages. In other transfers this value will range  from BaseID - 3 to BaseID + 3. The number can range between 4 and 4,25 billion
(4 ~ 4 250 000 000).

3. This field is a QWord, and contains the offset of the data you are sending, if the size is over  1202 bytes. For example, if you send 2404 bytes, the first message would contain the value  zero (seeing you haven’t send something yet), and the second message would have the value  1202, because you just send 1202 bytes.

4. This field is once again a QWord, and contains the size of total data being send in this total. If there is no data you can leave this to zero and often the Flag field (field 6) should be set to the value of 2.

5. This field is a DWord and contains the size of the data being send in this message. Note that “data” does NOT include the headers, only the data send between the Header and the Footer! For example, when sending a 5000 bytes file, field four would contain the value of 5000, and this field would contain only 1202, because you can’t transfer more than 1202 bytes in one message. This field and the fourth field are equal to each other when you aren’t sending actually file data (or Ink data in our case).


6. The sixth field, DWord, is the Flag field. The value of this field is 0 when no Flags are  specified. It will be 2 when the message is a reply to another message, 8 if there’s an error in  the binary fields of the received packet. The Flag will contain the value 32 if you are sending  DP or CE data, and the value 16777264 when it’s data of a file transfer.

7. This DWord contains the BaseID of the previous received message, *if* the SessionID is not  included in the binary headers, nor in the data sent in this message. Seeing the SessionID is  specified when sending Ink you can just put a random number here (1 ~ 1 000 000 000  would be good enough).

8. This field (A DWord) contains the value of the seventh field of the previous received message.

9. The ninth field is a QWord, and contains the value of the fourth field of the previous received  message.

10. This DWord comes AFTER the data, and therefore it’s the Footer. This DWord contains the  value zero when there is no actual file data (DP’s, CE’s etc) being send. It has the value 1  hen you send DP’s, CE’s or other data, and it has the value 3 when sending Ink.