Description of the Two DB connection modes provided by the DB2 database

This article mainly tells you about the two DB connection methods provided by the DB2 database: type1 and type2. In the type1 connection, connect will disconnect the connected DB2, A transaction can only connect to one database. In the type2 connection, connect retains the connected database and connects to a new database. Such a transaction is called a distributed unit of work.

Both methods do not allow the AP to connect to a DB multiple times at the same time!

Below are some type2 experiments performed under CLP:

 
 

  
  
QUOTE:  
  
  
$ db2 list applications  
 
 

Authorization identity Application name application identity DB proxy process

Handle name serial number

 
 

  
  
DB2ADMIN db2dasstm.exe 10 *LOCAL.DB2.00A180010035 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 9 *LOCAL.DB2.00A180010034 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 8 *LOCAL.DB2.00A180010020 DWCTRLDB 1   
  
  
$ db2 connect to otherdb  
 
 

Database connection information

Database Server = DB2 database/NT 8.1.2

SQL authorization id = DAVID

Local Database alias = OTHERDB

 
 

  
  
$ db2 connect to sample 
 
 

Database connection information

Database Server = DB2/NT 8.1.2

SQL authorization id = DAVID

Local Database alias = SAMPLE

$ Db2 list applications

Authorization identity Application name application identity DB proxy process

Handle name serial number

 
 

  
  
DAVID db2bp.exe 22 *LOCAL.DB2.012480161735 SAMPLE 1   
  
  
DB2ADMIN db2dasstm.exe 10 *LOCAL.DB2.00A180010035 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 9 *LOCAL.DB2.00A180010034 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 8 *LOCAL.DB2.00A180010020 DWCTRLDB 1   
  
  
$ db2 set client connect 2  
 
 

The DB20000I set client Command is successfully completed.

 
 

  
  
$ db2 connect to otherdb 
 
 

Database connection information

Database Server = DB2/NT 8.1.2

SQL authorization id = DAVID

Local Database alias = OTHERDB

 
 

  
  
$ db2 list applications 
 
 

Authorization identity Application name application identity DB proxy process

Handle name serial number

 
 

  
  
DAVID db2bp.exe 23 *LOCAL.DB2.012480161849 OTHERDB 1   
  
  
DAVID db2bp.exe 22 *LOCAL.DB2.012480161735 SAMPLE 1   
  
  
DB2ADMIN db2dasstm.exe 10 *LOCAL.DB2.00A180010035 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 9 *LOCAL.DB2.00A180010034 DWCTRLDB 1   
  
  
DB2ADMIN db2dasstm.exe 8 *LOCAL.DB2.00A180010020 DWCTRLDB 1 
 
 

The above test did not test transaction commit. If the test is to turn off the automatic commit of command option, you can test the connection and modification of multiple DB databases in a transaction! In addition, there are three types of type2 connections: syncpoint onephase (default), syncpoint twophase, and syncpoint none.

Using type2 connection, you can open multiple connections in a command window, but the operation is only valid for the last connection. If you want to switch, you can use set connection;