PostgreSQL JDBC driver Connection.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE) failures - Mailing list pgsql-hackers
From | Dave Tenny |
---|---|
Subject | PostgreSQL JDBC driver Connection.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE) failures |
Date | |
Msg-id | 3F303134.7050804@comcast.net Whole thread Raw |
List | pgsql-hackers |
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() }
pgsql-hackers by date: