Thread: Re: [JDBC] Out of memory error on huge resultset

> > > > To work
> > > > around this you can use explicit cursors (see the DECLARE CURSOR,
> > > > FETCH, and MOVE sql commands for postgres).

I'm unable to get this to work using the default distribution JDBC driver. 
(7.2). Here's a code snippet
     conn.setAutoCommit(false) ;     stmt.execute("BEGIN") ;     stmt.execute("DECLARE mysursor CURSOR FOR SELECT icol
FROMmtable") ;     ResultSet rs = null ;     if (stmt.execute("FETCH 10000 IN mycursor"))rs = stmt.getResultSet() ;
 

The FETCH statement returns an update count of 1, but no ResultSet.
If I try executeQuery, a "no rows found" exception is thrown.

Equivalent code in the C library interface works just fine.

I need a workaround, because default ResultSet processing in the JDBC
driver (and also the jxDBCon driver) pretty much blow out the memory 
of the JVM. 

This code work for me :Connection db = DriverManager.getConnection(url,user,passwd);PreparedStatement st =
db.prepareStatement("begin;declarec1 cursor for 
 
select * from a");st.execute();st = db.prepareStatement("fetch 100 in c1");ResultSet rs =
st.executeQuery();//rs.setFetchSize(100);while(rs.next() ) {    s = rs.getString(1);    System.out.println(s);}st =
db.prepareStatement("commit");st.execute();st.close();db.close();

regards
Haris Peco
On Wednesday 16 October 2002 01:55 pm, Dave Tenny wrote:
> > > > > To work
> > > > > around this you can use explicit cursors (see the DECLARE CURSOR,
> > > > > FETCH, and MOVE sql commands for postgres).
>
> I'm unable to get this to work using the default distribution JDBC driver.
> (7.2). Here's a code snippet
>
>       conn.setAutoCommit(false) ;
>       stmt.execute("BEGIN") ;
>       stmt.execute("DECLARE mysursor CURSOR FOR SELECT icol FROM mtable") ;
>       ResultSet rs = null ;
>       if (stmt.execute("FETCH 10000 IN mycursor"))
>     rs = stmt.getResultSet() ;
>
> The FETCH statement returns an update count of 1, but no ResultSet.
> If I try executeQuery, a "no rows found" exception is thrown.
>
> Equivalent code in the C library interface works just fine.
>
> I need a workaround, because default ResultSet processing in the JDBC
> driver (and also the jxDBCon driver) pretty much blow out the memory
> of the JVM.
>
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