Hi,
Thanks for your interest in MonetDB/SQL.
I looked through your example code. I think it can be summarised as follows:
Client A Client B setAutoCommit(false) setAutoCommit(false) create table X; commit; (1) savepoint s1; insert y into X; release savepoint s1; select * from X; commit; (2) select * from X; commit; (3)
Now the actual problem is that client B doesn't see the inserted row by A. Without commit marked with (1), B does return the row inserted by A.
I could limit this problem to a single user problem as follows:
(pegasus:~/develop/MonetJDBC) fabian% java -jar jars/MonetDB_JDBC.jar Connection warning: database specifier not supported on this server (mserver_sql), protocol version 4 Welcome to the MonetDB interactive JDBC terminal! Database: MonetDB 4.9.2 Driver: MonetDB Native Driver 1.2 (Blunt+) Type \q to quit, \h for a list of available commands auto commit mode: on monetdb-> start transaction; auto commit mode: off monetdb-> create table x (id int); Operation successful
monetdb-> commit; auto commit mode: on monetdb-> start transaction; auto commit mode: off monetdb-> savepoint s1;
monetdb-> insert into x values (1); 1 affected row
monetdb-> release savepoint s1;
monetdb-> select * from x; +------------+ | id | +============+ | 1 | +------------+ 1 row
monetdb-> commit; auto commit mode: on monetdb-> select * from x; +------------+ | id | +============+ +------------+ 0 rows
monetdb->
It appears that on the last commit, the inserted row is gone. Something which has something to do with the savepoint, because if I omit it, the last select does return my 1.
Niels, can you look into this issue?
Andrei Martsinchyk wrote:
Hello,
I am trying to use MonetDB as a backend for Java application I am developing. I have noticed that inserts the application does have no effect. Statements are executed without exceptions, but data rows do not get into table. I have investigated the problem and have figured out that problem is in transaction and savepoint handling. If transaction had savepoints, it could be silently rolled back when Connection.commit() is called. I have finished with short Java program that demonstrate the bug(?), I am attaching it to the message. Please, take a look. I tested with MonetDB-4.8.2+sql-2.8.2 (release, source tarball) and with MonetDB-4.8.3+sql-2.8.3 (nightly build, August 30). Platforms: 32-bit Linux RedHat 9, 32-bit Linux Ubuntu 5.04
-- Best regards, Andrei Martsinchyk mailto:andrei.martsinchyk@gmail.com