FreeTDS Development Group

["Lowden, James K" <LowdenJK AT bernstein.com>]

> From: Thompson, Bill D (London)
> Sent: Tuesday, April 12, 2005 8:36 AM
> 
> I'll have a go at ct_options(). 
> I had started to look at it anyway.

Sounds good, Bill.  

> I reckon that the ctlibrary ct_options(CS_OPT_CHAINXACTS), 
> and its partner "SET" option "SET CHAINED..", 
> are the same as SQL server's "SET IMPLICIT_TRANSACTIONS ON" 
> command. They seem to be the same thing as far as I can tell.

I think so; that's what I had in mind.  I haven't traced a ct-lib
conversation with tcpdump.  

We're going to need a whole new structure, to support the GET option.
The information is not always (conveniently) available from the server,
and the Open Client Client-Library/C Reference Manual indicates the
settings are maintained by the library:

"
A Client-Library application sets and clears Adaptive Server
query-processing
options in one of two ways:

* By using a Transact-SQL language command (set)
* By calling ct_options

An application may use only one of these methods; otherwise, Client-
Library/server communications may become confused.

The ct_options method is recommended because it allows an application to
check the status of an option, which is not allowed by the Transact-SQL
set
command.
"

I don't see how "communications may become confused"; I don't see any
reason for ct-lib to refer to settings that were transmitted to the
server.  But I can easily see that an application (or application
programmer) might become confused, if it sent a language command and
then attempted to ascertain the new status with ct_options().  

It looks to me like Sybase wanted to provide the appearance of being
able to interrogate the server's status, but supplied responses from a
local one-way cache.  Maintaining 1 datum in 2 places is always a can of
worms....  

--jkl


-----------------------------------------
The information contained in this transmission may contain privileged and
confidential information and is intended only for the use of the person(s) 
named
above. If you are not the intended recipient, or an employee or agent 
responsible
for delivering this message to the intended recipient, any review, 
dissemination,
distribution or duplication of this communication is strictly prohibited. If 
you are
not the intended recipient, please contact the sender immediately by reply 
e-mail
and destroy all copies of the original message. Please note that we do not 
accept
account orders and/or instructions by e-mail, and therefore will not be 
responsible
for carrying out such orders and/or instructions.  If you, as the intended 
recipient
of this message, the purpose of which is to inform and update our clients, 
prospects
and consultants of developments relating to our services and products, would 
not
like to receive further e-mail correspondence from the sender, please "reply" 
to the
sender indicating your wishes.  In the U.S.: 1345 Avenue of the Americas, New 
York,
NY 10105.