Re: driver ODBC-PostreSQL, cursor and transaction isolation level

olivier dorie wrote:
> Hello,
>
>
> I have some problems to have a transaction isolation level serializable
> with postgresql-ODBC driver for windows by using the ODBC cursor
> (UseDeclareFetch=1).
>
>
> My database is on PostgreSQL 8.3.7/ Linux.
>
> I use the postgresql-ODBC version 8.03.04 for windows.
>
> I make this test with the default_transaction_isolation = 'read
> committed' and after with the default_transaction_isolation =
> 'serializable' on the server. The results are the same.
>
>
> I do the followings operations in a c++ programm:
>
> * I open 2 connections on my database with the ODBC drivers:
> “connexion1” and “connexion2”
> o /CDatabase * db1 = new CDatabase ;///
> o /CDatabase * db2 = new CDatabase///
> o /db1->OpenEx (chaine_connection_mydatabase,
> CDatabase::noOdbcDialog);///
> o /db2->OpenEx (chaine_connection_mydatabase,
> CDatabase::noOdbcDialog)///
> * I ask for the number of tuples of table “table1” à n tuples:
> o /CRecordset crs (//db1)/
> o /crs.Open (CRecordset::snapshot, "SELECT count (*) FROM
> table1;")///
> * I make the “connexion1” serializable :
> o /db1->ExecuteSQL (“BEGIN TRANSACTION;”) /
> o /db1->ExecuteSQL (“SET TRANSACTION ISOLATION LEVEL
> SERIALIZABLE;”)/

ODBC doesn't recommend to call dbms specific commands to control
transaction. Please use BeginTrans/CommitTrans/Rollback instead.

Anyway I improved the handling of transaction under useDeclareFetch
mode a little. Please try the drivers on testing for 8.4.0100 at
http://www.geocities.jp/inocchichichi/psqlodbc/index.html
.

regards,
Hiroshi Inoue