Using IBM DB2 with unixODBC

I have had a number of requests from people wanting to connect to IBM's DB2

from Linux via unixODBC. This short document details what I know about this at

the moment. If anyone can contribute more imformation then please contact me

at the address at the end of the document.

This document originally refered to the 6.1 version of DB2, since then I have

tried the 7.1 build and with a couple of changes, these are detailed at the

end of this document.

First, install the DB2 Client access package from IBM it will install the IBM

CLI driver, this works with unixODBC as a ODBC driver.

Using the install in the Client Access package, setup the client access to

give you a instance name (ie db2inst1), then setup your odbcinst.ini entry

like this.

[DB2]

Description = DB2 Driver

Driver = /usr/IBMdb2/V6.1/lib/libdb2.so

FileUsage = 1

DontDLClose = 1

The DontDLClose is required to avoid a problem in the driver when dynamically

loaded (I suspect its registering a exit function which isn't being called).

Then setup your odbc.ini like this.

[sample]

Description = Test to DB2

Driver = DB2

(Driver 를 DB2를 넣으면 않되더라고요. 그래서 /usr/IBMdb2/V7.1/lib/libdb2.so 넣으면 되요)

Then when it comes to connecting, you MUST have the environment variable

DB2INSTANCE set to a vaild db2 instance, so for instance to connect with isql

export DB2INSTANCE=db2inst1

isql -v sample db2inst1 ibmdb2

That should be all there is to it.

Version 7.1

Since originally creating this document, IBM have released a new version of

DB2 7.1. I have tried the 7.1 build and with a couple of changes, the same

method seems to work fine. The only difference being the name of the package,

where the document used to refer to the DB2 Client access package, the CLI

driver is now to be found in the DB2 Personal Developer's Edition V7.1.

If using the 7.1 build the path to the library is now

Driver = /usr/IBMdb2/V7.1/lib/libdb2.so

I have also found that you need to add "/usr/IBMdb2/V7.1/lib" to /etc/ld.so.conf.

It has been reported that this installation doesn't work in some situations.

the attempt to open the driver fails, and cannot find a symbol sqltevents in

libdpdcf.a. I hav'nt had this problem, so I wonder if there is a difference

between platform, or builds of the DB2 instance. If anyone has any more info

on this let me know.

Another useful hint. Somewho has been using PHP+DB2 on AIX via unixODBC to a

BIG IBM server (4 processors, bags of core etc), and finding it was slow. It

turns out there is a bug in IBM's TCP/IP stack. after looking at this and

setting this

$ su - db2inst1

$ db2set DB2TCPCONNMGRS=1

To quote "... the difference was UNBELIEVABLE !!!". Thanks Eric.

If this is of any help to someone, good, any problems let me know.

Nick Gorham

출처 : http://www.unixodbc.org/doc/db2.html