A need exist to add a new connection to the instance dynamically without any down time.

Starting with Informix version 11.50.xC6 we have the ability to Dynamically Start, Stop and Restart Listen threads with the onmode -P command or by using the SQL Admin API. 

This feature allows a new listener thread to be started on a port without the need to restart the database server. Adding new entries in to the sqlhosts file and the DBSERVERALIAS parameter of the onconfig file and executing the onmode -P or SQL API commands will allow new connections to utilize the new server name.

Steps:

1. Modify the sqlhosts to add the new connection:

      new_test_tcp onsoctcp myhost 4567 

2. Modify the DBSERVERALIAS parameter of the onconfig file: 

      DBSERVERALIASES main_prim_shm:new_test_tcp 

3. Start a listener thread for the new alias:

       onmode -P start new_test_tcp

OR use the sysadmin SQL API :

      execute function admin("start listen","new_test_tcp");

Changing the DB2 server's hostname.

Perform the following on the DB2 server:

1) Login as the dasadm user on UNIX/Linux or Local Administrator on Windows. Stop the DB2 Administration Server (DAS):

db2admin stop

db2stop

• UNIX/Linux
  db2iset -g DB2SYSTEM=<new hostname> 
  
• Windows 
  db2set -g DB2SYSTEM=<new hostname>

• UNIX/Linux:
  <db2 instance home directory>/sqllib/db2nodes.cfg
  
  
• All Windows flavors running DB2 v8 and v9.1: 
  Program Files\IBM\SQLLIB\DB2\db2nodes.cfg 
  
  
• Windows XP and 2003 running DB2 v9.5: 
  Documents and Settings\All Users\Application Data\IBM\DB2\<DB2COPY>\DB2\db2nodes.cfg
  
  NOTE: Application Data is a hidden folder
  
  
• Windows Vista and later operating systems: ProgramData\IBM\DB2\<DB2COPY>\DB2\db2nodes.cfg
  

db2 list admin node directory show detail 

If there are no Admin Node Directory entries then you can skip the next 2 steps. It simply means that you haven't started the Control Center. The Admin Node Directory will get updated the next time the Control Center is started, based upon the current hostname. 

db2 uncatalog node <nodename> 

db2 catalog admin tcpip node <nodename> remote <new hostname> system <new hostname> 

<nodename> can be anything you want it to be (8 characters or less). It does not relate directly to the hostname itself.

db2 update admin cfg using DB2SYSTEM <new hostname> 
db2 update admin cfg using SMTP_SERVER <new hostname>

db2admin start

db2start

This document explains how to count the number of processors on your system as IBM Informix® products defines a processor. Various IBM Informix® products are tuned based on the number of processors on your system. The NUMCPUVPS or VPCLASS onCONFIG configuration parameter, for example, should be set to one less than the actual number of physical CPUs present in the server. 

A processor is a device that operates on core. With multiple core technology, this can be a single device or a device that has multiple core "processors". IBM Informix® products consider these multiple cores as separate physical processors. 

On any HP-UX system, the ioscan command lists how many processors(single or multiple core) are on your system. The ioscan command (located in/usr/sbin) outputs a list of all IO devices. Each line in the output that begins with processor represents a processor that is either a single device or an instance of a multiple core device. 

Use the following command line to include the processors in the output and automatically count them using grep (pattern match) and wc (character count). For more information see your Operating System man pages.

/usr/sbin/ioscan -kf | grep processor | wc -l

Example 1: 

This example is from a machine with 2 processors. 


$   /usr/sbin/ioscan -kf|grep processor|wc -l 
2 

Note: You would set the NUMCPUVPS or VPCLASS parameter to 1 in this example. 

Example 2: 

This example is from a machine with 4 processors. 

$   /usr/sbin/ioscan -kf|grep processor|wc -l 
4

This example is from a machine with 4 processors. The Line count (wc -l) is left off to show the actual ioscan and grep output. 


$   /usr/sbin/ioscan -kf|grep processor 
processor   0  120            processor  CLAIMED     PROCESSOR    Processor 
processor   1  121            processor  CLAIMED     PROCESSOR    Processor 
processor   2  122            processor  CLAIMED     PROCESSOR    Processor 
processor   3  123            processor  CLAIMED     PROCESSOR    Processor 

Note: You would set the NUMCPUVPS or VPCLASS parameter to 3 in this example.

On AIX you use the command lsdev to determine how many CPUs your system has. The command lsdev (located in /usr/sbin) is used to list the system devices. Use it with the following options to list all processors one per line:

/usr/sbin/lsdev -C -c processor

Example: 

This example is from a single processor system. 


$ lsdev -C -c processor 
proc0 Available 00-00 Processor

Question

A sample ESQL/C program to insert data into a BLOB (TEXT) column using ESQL/C.

Answer

Run this SQL command:

select sh_curmaxcons, sh_ovlmaxcons from sysmaster:sysshmvals;

sh_curmaxcons - updated as new connections are made, reset after a bounce. This means that the value will reset for each shut down and start up of the server. 

sh_ovlmaxcons - updated at each checkpoint, persists over bounces, and upgrades. The ovlmaxcons value is initialized the first time you INSTALL the server. Thereafter, the maximum # of connections is recorded in the sysmaster database. Even after an upgrade from 9.4 to 10.0, that value will not be reset or lost. 

With IBM® Informix® Dynamic Server™ 11.10, it is possible to apply filters during a backup and restore with both ontape and onbar. These filters basically are external programs which are called before the data is written or read either to or from disk or the storage manager. The filter programs expect data from stdin and will send their output, the processed data, to stdout. The most common example for that is to call a compression program, but it can also be used for encryption or other changes to the data. 
If you want to use a filter to compress the data of your backup, you can define a backup filter in the Informix Configuration file like below

Example

For UNIX platforms:
BACKUP_FILTER /usr/bin/compress

For Microsoft® Windows platforms:
BACKUP_FILTER c:\cygwin\bin\gzip.exe

RESTORE_FILTER /usr/bin/uncompress

RESTORE_FILTER 'c:\cygwin\bin\gzip.exe -d'

Starting with Oracle 11gR2 clients will no longer contain the 32bit libraries. For that reason, a 32bit Oracle client has to be installed, to be able to use Optim on Linux x64 as server.

To get the full functionality of Optim, use the "Administrator" installation type. This type contains all libraries needed and the binaries, for example, sqlldr, the Oracle SQL Loader, sometimes needed.

see also:
Oracle® Database Client Installation Guide
11g Release 2 (11.2) for Linux
1.2.3 Separate 32-Bit Client Shiphome for 64-Bit Ports


The supported database versions of Oracle with a current Oracle client you can find at Oracle directly:
Note:207303.1 "Oracle Client / Server Interoperability Support"

For 11.1-clients that means: 
Server must have 9.2.0.4 or higher, 9.2.0.1 is not supported.