I looked at that old message...some comments: First of all we need
transaction functionality on select as well as insert, so I guess we'll
add methods for doTransactionSelect, doTransactionInsert,
doTransactionUpdate and doTransactionDelete. While this will be fine to
fix the postgres prob. It's not really useful for many types of
transactions, for example if you want to update something, then delete
something, and then update something else, all in one transaction, it
would be impossible. I guess we can start with this implementation, and
then later create a class which contains an ordered list of database
operations which should happen within a transaction.
What do you think?
-Nissim
John McNally wrote:
>
> As a core developer of BasePeer, but someone who is having trouble finding
> the time to follow these discussions carefully, I am going to make a
> suggestion. Please tell me nicely why the following will not work:
>
> Add transaction functionality to BasePeer as I specified a while back. This
> should be quite generally useful code. I assume I will have some need for
> it in the future and will add it when I need it, but if others are needing
> it now, why not submit the code.
>
> Add the postgres specific code regarding the object_data column in the peer
> where it is being updated. I have no objection to this update being
> generically a transaction if it is handled gracefully in the db's that don't
> support transactions (maybe there is a metadata property on transaction
> support). Otherwise add specific code for postgres here.
>
> John McNally
>
> ----- Original Message -----
> From: Nissim <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Monday, June 26, 2000 4:04 PM
> Subject: [PATCH] Postgresql (long)
>
> > Hi all,
> >
> > This is about how to get the large object stuff working in turbine.
> > there's a bunch of patches, and some of the stuff isn't all that clean,
> > but I'd need some suggestions because cleaning it up might require
> > changes to public interfaces...
> >
> > First of all, to run turbine with pgsql, you have to get the newest
> > pgsql JDBC driver, and then apply a patch to it. Find the patch here:
> > http://www.mail-archive.com/turbine%40list.working-dogs.com/msg02249.html
> >
> > Note: if you use OID for something other than large object references
> > and you need it to look like an int in the JDBC metadata this patch will
> > break that. If you have no idea what that means, you're probably safe
> > using it.
> >
> > Next I have patches for turbine, because to read or write object data
> > from postgres, you must be within a transaction. The following code
> > adds some stuff to the DB interface, and the BasePeer to check if the
> > database you're using requires this functionality, and then to create
> > the transaction if you do.
> >
> > <Questions for turbine coders>
> > 1) In the BasePeer.doUpdate, we can check whether the table(s) getting
> > updated contain an object column, and only execute the transaction then,
> > but in the executeQuery method we don't have access to the table names,
> > so we have to make the transaction every time if it's postgres, should
> > we try to fix that? We'd have to get the connection from the pool in
> > the doSelect method, and then pass it to the executeQuery, but that
> > would change the interface...should we add another executeQuery method
> > that takes a Connection param?
> >
> > 2) To test whether a column is objectdata, we don't have the SQL type,
> > so I just check if it's not instanceof String, Date or Number then it's
> > objectdata...should we add the SQL type to the columnMap...it's not
> > easy, because of all the public helper methods have the same interface
> > as the new methods would have...because length is an int and
> > java.sql.Types.* are ints...
> > </Questions for turbine coders>
> >
> > Thanks
> >
> > -Nissim
> >
> > Patches:
> >
> > Index: docs/schemas/Postgres_users_roles_permissions.sql
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/docs/schemas/Postgres_users_roles_permissions.
> sql,v
> > retrieving revision 1.1
> > diff -r1.1 Postgres_users_roles_permissions.sql
> > 83c83
> > < OBJECTDATA varchar (255), -- oder doch bytea???
> > ---
> > > OBJECTDATA oid,
> > Index: src/java/org/apache/turbine/om/peer/BasePeer.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/om/peer/BasePeer.j
> ava,v
> > retrieving revision 1.25
> > diff -r1.25 BasePeer.java
> > 867a868,879
> > >
> > > Statement stmt = null;
> > > boolean doTransaction = DBBroker.getInstance()
> > > .getDB( dbName )
> > > .objectDataNeedsTrans();
> > > if (doTransaction)
> > > {
> > > stmt = connection.createStatement();
> > > stmt.executeUpdate("BEGIN TRANSACTION");
> > > stmt.close();
> > > }
> > >
> > 870a883,890
> > >
> > > if (doTransaction)
> > > {
> > > stmt = connection.createStatement();
> > > stmt.executeUpdate("COMMIT TRANSACTION");
> > > stmt.close();
> > > }
> > >
> > 1062a1083,1100
> > >
> > > Statement stmt = null;
> > > boolean doTransaction = false;
> > > if ( db.objectDataNeedsTrans() )
> > > {
> > > for (int i = 0; i<tables.size(); i++)
> > > {
> > > doTransaction = doTransaction ||
> > > containsObjectColumn(dbMap,
> tables.get(i));
> > > }
> > > }
> > >
> > > if ( doTransaction )
> > > {
> > > stmt = dbCon.createStatement();
> > > stmt.executeUpdate("BEGIN TRANSACTION");
> > > stmt.close();
> > > }
> > 1122a1161,1168
> > >
> > > if ( doTransaction )
> > > {
> > > stmt = dbCon.createStatement();
> > > stmt.executeUpdate("COMMIT TRANSACTION");
> > > stmt.close();
> > > }
> > >
> > 1230a1277,1289
> > > }
> > >
> > > /**
> > > * Determines whether any of the columns in the table are object
> > > * (binary) data.
> > > *
> > > * @return true if the table contains a column which will be a SQL
> > > * large object.
> > > */
> > > public static boolean containsObjectColumn(DatabaseMap dbMap, String
> tableName) throws Exception
> > > {
> > > TableMap tmap = dbMap.getTable(tableName);
> > > return tmap.containsObjectColumn();
> > Index: src/java/org/apache/turbine/util/db/map/TableMap.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/map/TableM
> ap.java,v
> > retrieving revision 1.6
> > diff -r1.6 TableMap.java
> > 181a182,199
> > > * Returns true if this tableMap contains a column with object data.
> > > */
> > > public boolean containsObjectColumn()
> > > {
> > > Enumeration e = columns.elements();
> > > while (e.hasMoreElements())
> > > {
> > > Object theType = ((ColumnMap)e.nextElement()).getType();
> > > if (! ( theType instanceof String ||
> > > theType instanceof Number ||
> > > theType instanceof java.util.Date ) )
> > > {
> > > return true;
> > > }
> > > }
> > > return false;
> > > }
> > > /**
> > Index: src/java/org/apache/turbine/util/db/pool/DB.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DB.ja
> va,v
> > retrieving revision 1.8
> > diff -r1.8 DB.java
> > 123a124,126
> > > /** The method is used to chek whether
> > > writing large objects to the DB requires a transaction. */
> > > public abstract boolean objectDataNeedsTrans();
> > Index: src/java/org/apache/turbine/util/db/pool/DBDB2App.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBDB2
> App.java,v
> > retrieving revision 1.4
> > diff -r1.4 DBDB2App.java
> > 145a146,153
> > >
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBHypersonicSQL.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBHyp
> ersonicSQL.java,v
> > retrieving revision 1.3
> > diff -r1.3 DBHypersonicSQL.java
> > 131a132,139
> > >
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBInstantDB.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBIns
> tantDB.java,v
> > retrieving revision 1.5
> > diff -r1.5 DBInstantDB.java
> > 128a129,135
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBInterbase.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBInt
> erbase.java,v
> > retrieving revision 1.1
> > diff -r1.1 DBInterbase.java
> > 136a137,143
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBMM.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBMM.
> java,v
> > retrieving revision 1.5
> > diff -r1.5 DBMM.java
> > 134a135,142
> > >
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBOracle.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBOra
> cle.java,v
> > retrieving revision 1.5
> > diff -r1.5 DBOracle.java
> > 133a134,141
> > >
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBPostgres.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBPos
> tgres.java,v
> > retrieving revision 1.4
> > diff -r1.4 DBPostgres.java
> > 146a147,153
> > > /**
> > > * Returns true because transactions are necessary in postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return true;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBSybase.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBSyb
> ase.java,v
> > retrieving revision 1.3
> > diff -r1.3 DBSybase.java
> > 132a133,140
> > >
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> > Index: src/java/org/apache/turbine/util/db/pool/DBWeblogic.java
> > ===================================================================
> > RCS file:
> >
> /products/cvs/turbine/turbine/src/java/org/apache/turbine/util/db/pool/DBWeb
> logic.java,v
> > retrieving revision 1.4
> > diff -r1.4 DBWeblogic.java
> > 126a127,133
> > > /**
> > > * Returns false because transactions are only necessary in
> postgres.
> > > */
> > > public boolean objectDataNeedsTrans()
> > > {
> > > return false;
> > > }
> >
> >
> > ------------------------------------------------------------
> > To subscribe: [EMAIL PROTECTED]
> > To unsubscribe: [EMAIL PROTECTED]
> > Search: <http://www.mail-archive.com/turbine%40list.working-dogs.com/>
> > Problems?: [EMAIL PROTECTED]
> >
>
> ------------------------------------------------------------
> To subscribe: [EMAIL PROTECTED]
> To unsubscribe: [EMAIL PROTECTED]
> Search: <http://www.mail-archive.com/turbine%40list.working-dogs.com/>
> Problems?: [EMAIL PROTECTED]
------------------------------------------------------------
To subscribe: [EMAIL PROTECTED]
To unsubscribe: [EMAIL PROTECTED]
Search: <http://www.mail-archive.com/turbine%40list.working-dogs.com/>
Problems?: [EMAIL PROTECTED]
