Re: how to use transaction isolation
This is a discussion on Re: how to use transaction isolation within the Pgsql General forums, part of the PostgreSQL category; --> On 4/10/08, Gong <fredkung@sohu.com> wrote: > > > In the java code below, I set the transaction isolation to ...
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04-11-2008, 01:53 AM
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 Re: how to use transaction isolation On 4/10/08, Gong <fredkung@sohu.com> wrote: > > > In the java code below, I set the transaction isolation to serialization. > > public class IsolationTest { > > private static String select = "select * from tmp where url = 'aaa'"; > > public static void main(String[] args) throws Exception{ > //ConncetionFactory is a factory class for managing connection > Connection con = ConnectionFactory.getConnection(); > > > con.setTransactionIsolation(Connection.TRANSACTION _SERIALIZABLE); > con.setAutoCommit(false); > > Statement smt = con.createStatement(); > ResultSet r1 = smt.executeQuery(select); > System.out.println(r1.next()); //(1) > con.commit(); //(2) > > ResultSet r2 = smt.executeQuery(select); > System.out.println(r2.next()); //(3) > con.commit(); > smt.close(); > > ConnectionFactory.closeConnection(); > } > } > > I set a break point at (2), then I run this code in debug mode. When it > suspended at (2), line(1) print "false". Then, I execute an insert statement > in pgadmin: insert into tmp values('aaa'), after that I continued to run the > code, and line(3) print "true". I have set the transaction isolation to > serialization, didn't the two select statements print the same result? Your commit at (2) ends the transaction, and the second select runs in a new one. jan -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general      |
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04-12-2008, 02:05 AM
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| Re: how to use transaction isolation On 4/11/08, Jan de Visser <jdevisser@digitalfairway.com> wrote: >Your commit at (2) ends the transaction, and the second select runs in >a new one. >jan -- I got it. I didn't notice it is the *TRANSACTION* isolation. Thanks a lot! -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general |
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