Thread: Re: [HACKERS] PostgreSQL JDBC driver Connection.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE)
Re: [HACKERS] PostgreSQL JDBC driver Connection.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE)
From
Barry Lind
Date:
Dave,
I am moving this to the jdbc mail list.
I can't reproduce your problem. You indicate that you are using the
beta1 driver for 7.3. Can you retry with the latest 7.3 driver from
jdbc.postgresql.org? Your test case works fine for me with the current
development driver running against a 7.3.2 database.
thanks,
--Barry
Dave Tenny wrote:
> I'm using 7.3.3 of the server, and pg73b1jdbc2.jar for the JDBC driver.
>
> Various permutations of calls to the setTransactionIsolation all fail to
> yield a driver state that will tell me that it is set up for
> serializable transactions.
>
> Help!?
>
> I googled, I grepped. I find mention of problems with respect to JDBC
> tests failing and patched, but see no reports of this as a bug,
> or any fixes for it.
>
> Here's the output from the attached program:
>
> javac -classpath .:/usr/share/pgsql/pg73b1jdbc3.jar TxnIsolation.java &&
> java -classpath .:/usr/share/pgsql/pg73b1jdbc3.jar TxnIsolation
> supportsTransactions(): true
> Default transaction isolation is 2
> supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED):
> false
> supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED):
> true
> supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ):
> false
> supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE):
> true
> Current transaction isolation is 2
> Transaction isolation after setting to TRANSACTION_SERIALIZABLE is 2
> ^^^^^^^^^^^^^^^^^^^^ HAVE A PROBLEM ^^^^^^^^^^^^^^^^^^^^
> Current auto commit is true
> After settting auto commit to false, it is false
> Transaction isolation after setAutoCommit() is 2
> Current connection readonly status is false
> Connection readonly after setting it to be readonly is true
>
> ---------------------------------------------------------------
>
> Moving the setTransactionIsolation call to before the setAutoCommit
> call also results in failure.
>
> To run the program, you'll need to change the database and userid
> parameters in the DriverManager.getConnection call to something that
> works for you.
>
>
> ------------------------------------------------------------------------
>
> import java.sql.* ;
> import java.io.* ;
> import java.util.* ;
>
> /**
> * Test JDBC transaction/connection stuff. In particular isolation levels.
> */
>
>
> class TxnIsolation
> {
> public static void main(String[] args) {
> try {
> // ---------------- MySql driver -----------------
> // -classpath .:/usr/java/mysql-connector-java-2.0.14/mysql-connector-java-2.0.14-bin.jar
> // RH9: -classpath .:/home/dave/mysql-connector-java-3.0.8-stable/mysql-connector-java-3.0.8-stable-bin.jar
> //Class.forName("com.mysql.jdbc.Driver") ;
> //Connection conn = DriverManager.getConnection("jdbc:mysql:///test", "dave", "") ;
> //String innodb = " TYPE=INNODB" ;
>
> // --------------- postgres 7.3.2 distribution JDBC2 driver linked as /usr/java/postgresql-jdbc.jar
> // -classpath .:/usr/java/postgresql-jdbc.jar
> Class.forName("org.postgresql.Driver") ;
> Connection conn = DriverManager.getConnection("jdbc:postgresql:test", "dave", "") ;
> String innodb = "" ;
>
>
> // Here we go.
>
> // Metadata
> DatabaseMetaData md = conn.getMetaData() ;
> System.out.println("supportsTransactions(): " + md.supportsTransactions()) ;
> System.out.println("Default transaction isolation is " + md.getDefaultTransactionIsolation()) ;
> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED): " +
> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED)) ;
> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED): " +
> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED)) ;
> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ): " +
> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ)) ;
> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE): " +
> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE)) ;
>
> // transactionIsolation
> // Theoretically important to call BEFORE setAutoCommit
> System.out.println("Current transaction isolation is " + conn.getTransactionIsolation()) ;
> conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE) ;
> System.out.println("Transaction isolation after setting to TRANSACTION_SERIALIZABLE is "
> + conn.getTransactionIsolation()) ;
> if (conn.getTransactionIsolation() != Connection.TRANSACTION_SERIALIZABLE)
> System.out.println("^^^^^^^^^^^^^^^^^^^^ HAVE A PROBLEM ^^^^^^^^^^^^^^^^^^^^") ;
>
> // autoCommit
> System.out.println("Current auto commit is " + conn.getAutoCommit()) ;
> conn.setAutoCommit(false) ;
> System.out.println("After settting auto commit to false, it is " + conn.getAutoCommit()) ;
> System.out.println("Transaction isolation after setAutoCommit() is "
> + conn.getTransactionIsolation()) ;
>
>
> // readOnly
> System.out.println("Current connection readonly status is " + conn.isReadOnly()) ;
> conn.setReadOnly(true) ;
> System.out.println("Connection readonly after setting it to be readonly is " + conn.isReadOnly()) ;
>
> }
> catch (Exception e) {
> e.printStackTrace() ;
> }
> } // main()
> }
>
>
> ------------------------------------------------------------------------
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster
Re: [HACKERS] PostgreSQL JDBC driver Connection.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE)
From
Dave Tenny
Date:
All set. I dowloaded drivers from jdbc.postgresql.org and that fixed the
problem.
Apparently the drivers that came with my distribution were not up to date.
Many thanks.
Dave
Barry Lind wrote:
> Dave,
>
> I am moving this to the jdbc mail list.
>
> I can't reproduce your problem. You indicate that you are using the
> beta1 driver for 7.3. Can you retry with the latest 7.3 driver from
> jdbc.postgresql.org? Your test case works fine for me with the
> current development driver running against a 7.3.2 database.
>
> thanks,
> --Barry
>
> Dave Tenny wrote:
>
>> I'm using 7.3.3 of the server, and pg73b1jdbc2.jar for the JDBC driver.
>>
>> Various permutations of calls to the setTransactionIsolation all fail
>> to yield a driver state that will tell me that it is set up for
>> serializable transactions.
>>
>> Help!?
>>
>> I googled, I grepped. I find mention of problems with respect to
>> JDBC tests failing and patched, but see no reports of this as a bug,
>> or any fixes for it.
>>
>> Here's the output from the attached program:
>>
>> javac -classpath .:/usr/share/pgsql/pg73b1jdbc3.jar TxnIsolation.java
>> && java -classpath .:/usr/share/pgsql/pg73b1jdbc3.jar TxnIsolation
>> supportsTransactions(): true
>> Default transaction isolation is 2
>> supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED):
>> false
>> supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED):
>> true
>> supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ):
>> false
>> supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE):
>> true
>> Current transaction isolation is 2
>> Transaction isolation after setting to TRANSACTION_SERIALIZABLE is 2
>> ^^^^^^^^^^^^^^^^^^^^ HAVE A PROBLEM ^^^^^^^^^^^^^^^^^^^^
>> Current auto commit is true
>> After settting auto commit to false, it is false
>> Transaction isolation after setAutoCommit() is 2
>> Current connection readonly status is false
>> Connection readonly after setting it to be readonly is true
>>
>> ---------------------------------------------------------------
>>
>> Moving the setTransactionIsolation call to before the setAutoCommit
>> call also results in failure.
>>
>> To run the program, you'll need to change the database and userid
>> parameters in the DriverManager.getConnection call to something that
>> works for you.
>>
>>
>> ------------------------------------------------------------------------
>>
>> import java.sql.* ;
>> import java.io.* ;
>> import java.util.* ;
>>
>> /**
>> * Test JDBC transaction/connection stuff. In particular isolation
>> levels.
>> */
>>
>>
>> class TxnIsolation
>> {
>> public static void main(String[] args) {
>> try {
>> // ---------------- MySql driver -----------------
>> // -classpath
>> .:/usr/java/mysql-connector-java-2.0.14/mysql-connector-java-2.0.14-bin.jar
>> // RH9: -classpath
>> .:/home/dave/mysql-connector-java-3.0.8-stable/mysql-connector-java-3.0.8-stable-bin.jar
>> //Class.forName("com.mysql.jdbc.Driver") ;
>> //Connection conn =
>> DriverManager.getConnection("jdbc:mysql:///test", "dave", "") ;
>> //String innodb = " TYPE=INNODB" ;
>>
>> // --------------- postgres 7.3.2 distribution JDBC2 driver
>> linked as /usr/java/postgresql-jdbc.jar
>> // -classpath .:/usr/java/postgresql-jdbc.jar
>> Class.forName("org.postgresql.Driver") ;
>> Connection conn =
>> DriverManager.getConnection("jdbc:postgresql:test", "dave", "") ;
>> String innodb = "" ;
>>
>>
>> // Here we go.
>>
>> // Metadata
>> DatabaseMetaData md = conn.getMetaData() ;
>> System.out.println("supportsTransactions(): " +
>> md.supportsTransactions()) ;
>> System.out.println("Default transaction isolation is " +
>> md.getDefaultTransactionIsolation()) ;
>>
>> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED):
>> " +
>>
>> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_UNCOMMITTED))
>> ;
>>
>> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED):
>> " +
>>
>> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_READ_COMMITTED))
>> ;
>>
>> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ):
>> " +
>>
>> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_REPEATABLE_READ))
>> ;
>>
>> System.out.println("supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE):
>> " +
>>
>> md.supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE))
>> ;
>>
>> // transactionIsolation
>> // Theoretically important to call BEFORE setAutoCommit
>> System.out.println("Current transaction isolation is " +
>> conn.getTransactionIsolation()) ;
>>
>> conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE) ;
>> System.out.println("Transaction isolation after setting to
>> TRANSACTION_SERIALIZABLE is "
>> + conn.getTransactionIsolation()) ;
>> if (conn.getTransactionIsolation() !=
>> Connection.TRANSACTION_SERIALIZABLE)
>> System.out.println("^^^^^^^^^^^^^^^^^^^^ HAVE A PROBLEM
>> ^^^^^^^^^^^^^^^^^^^^") ;
>>
>> // autoCommit
>> System.out.println("Current auto commit is " +
>> conn.getAutoCommit()) ;
>> conn.setAutoCommit(false) ;
>> System.out.println("After settting auto commit to false, it is
>> " + conn.getAutoCommit()) ;
>> System.out.println("Transaction isolation after setAutoCommit()
>> is "
>> + conn.getTransactionIsolation()) ;
>>
>>
>> // readOnly
>> System.out.println("Current connection readonly status is " +
>> conn.isReadOnly()) ;
>> conn.setReadOnly(true) ;
>> System.out.println("Connection readonly after setting it to be
>> readonly is " + conn.isReadOnly()) ;
>>
>> }
>> catch (Exception e) {
>> e.printStackTrace() ;
>> }
>> } // main()
>> }
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 4: Don't 'kill -9' the postmaster
>
>
>
>