Hi,
What's the word on this issue?
-Patrick
--
Patrick Linskey
BEA Systems, Inc.
_______________________________________________________________________
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> -----Original Message-----
> From: Patrick Linskey
> Sent: Wednesday, February 21, 2007 3:07 PM
> To: 'open-jpa-dev@incubator.apache.org'
> Subject: RE: svn commit: r510281 - in
> /incubator/openjpa/trunk:
> openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/
> openjpa-kernel/src/main/java/org/apache/openjpa/kernel/
> openjpa-persistence/src/main/java/org/apache/openjpa/persistence/
>
> Some comments:
>
> 1. What does "optimize for n" do? Do you have a link where I
> could read up on it?
>
> 2. Is there equivalent magic for other databases?
>
> 3. OpenJPA does support a means of passing Oracle hints along
> through to the DBDictionary. Should we be trying to reuse
> some of the capabilities here?
>
> 4. In the following snippets, I'd rather if we used
> 'Integer.valueOf(1)' or, better yet, a symbolic constant,
> instead of creating new integer all the time.
>
> > + fetch.setHint("openjpa.hint.optimize", new Integer(1));
>
> > + _query.getFetchConfiguration().
> > + setHint("openjpa.hint.optimize", new
> Integer(1));
>
> 5. I don't like the name 'openjpa.hint.optimize', as it's a
> bit ambiguous as to what's being optimized. I don't really
> know what 'optimize for' does, so I'm just guessing here, but
> how about 'openjpa.ExpectedRecordCount'?
>
> 6. How does the user access this from JPQL queries when they
> don't want to use a getSingleResult() call? Will it work to
> use the JPA query hint facilities, or do they have to use the
> broker APIs? Do we even care, since they could just use
> getSingleResult()? Maybe it's better to not allow this to be
> user-configurable, if we can always infer the right setting.
> But I'm guessing that sometimes the user might want to say
> that they expect 10 results or something like that
>
> 7. It seems like this could also be useful for when a
> one-to-one or a many-to-one is traversed.
>
> -Patrick
>
> --
> Patrick Linskey
> BEA Systems, Inc.
>
> ______________________________________________________________
> _________
> Notice: This email message, together with any attachments,
> may contain
> information of BEA Systems, Inc., its subsidiaries and
> affiliated
> entities, that may be confidential, proprietary,
> copyrighted and/or
> legally privileged, and is intended solely for the use of the
> individual
> or entity named in this message. If you are not the intended
> recipient,
> and have received this message in error, please immediately
> return this
> by email and then delete it.
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > Sent: Wednesday, February 21, 2007 2:50 PM
> > To: open-jpa-commits@incubator.apache.org
> > Subject: svn commit: r510281 - in /incubator/openjpa/trunk:
> > openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/
> > openjpa-kernel/src/main/java/org/apache/openjpa/kernel/
> > openjpa-persistence/src/main/java/org/apache/openjpa/persistence/
> >
> > Author: wisneskid
> > Date: Wed Feb 21 14:50:04 2007
> > New Revision: 510281
> >
> > URL: http://svn.apache.org/viewvc?view=rev&rev=510281
> > Log:
> > DB2 Optimize for clause enhancement
> >
> > Modified:
> >
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DB2Dictionary.java
> >
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DBDictionary.java
> >
> > incubator/openjpa/trunk/openjpa-kernel/src/main/java/org/apach
> e/openjpa/kernel/BrokerImpl.java
> >
> > incubator/openjpa/trunk/openjpa-persistence/src/main/java/org/
> apache/openjpa/persistence/QueryImpl.java
> >
> > Modified:
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DB2Dictionary.java
> > URL:
> > http://svn.apache.org/viewvc/incubator/openjpa/trunk/openjpa-j
> dbc/src/main/java/org/apache/openjpa/jdbc/sql/DB2Dictionary.ja
> va?> view=diff&rev=510281&r1=510280&r2=510281
> > ==============================================================
> > ================
> > ---
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DB2Dictionary.java (original)
> > +++
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DB2Dictionary.java Wed Feb 21 14:50:04 2007
> > @@ -20,6 +20,7 @@
> > import java.sql.SQLException;
> > import java.util.Arrays;
> >
> > +import org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration;
> > import org.apache.openjpa.jdbc.schema.Sequence;
> >
> > /**
> > @@ -33,7 +34,7 @@
> > validationSQL = "SELECT DISTINCT(CURRENT TIMESTAMP) FROM "
> > + "SYSIBM.SYSTABLES";
> > supportsSelectEndIndex = true;
> > -
> > + optimizeClause ="optimize for";
> > nextSequenceQuery = "VALUES NEXTVAL FOR {0}";
> >
> > sequenceSQL = "SELECT SEQSCHEMA AS SEQUENCE_SCHEMA, "
> > @@ -190,5 +191,21 @@
> > }
> > }
> > }
> > + }
> > +
> > + public String getOptimizeClause(JDBCFetchConfiguration fetch) {
> > + Integer rows = null;
> > + StringBuffer optimizeString = null;
> > + if (fetch.getHint("openjpa.hint.optimize") != null) {
> > + optimizeString = new StringBuffer();
> > + rows = (Integer)fetch.getHint("openjpa.hint.optimize");
> > + optimizeString.append("
> > ").append(optimizeClause).append(" ")
> > + .append(rows).append(" ");
> > + if(rows.intValue() > 1)
> > +
> optimizeString.append(rowsClause).append(" ");
> > + else
> > +
> optimizeString.append(rowClause).append(" ");
> > + }
> > + return optimizeString.toString();
> > }
> > }
> >
> > Modified:
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DBDictionary.java
> > URL:
> > http://svn.apache.org/viewvc/incubator/openjpa/trunk/openjpa-j
> dbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.jav
> a?> view=diff&rev=510281&r1=510280&r2=510281
> > ==============================================================
> > ================
> > ---
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DBDictionary.java (original)
> > +++
> > incubator/openjpa/trunk/openjpa-jdbc/src/main/java/org/apache/
> openjpa/jdbc/sql/DBDictionary.java Wed Feb 21 14:50:04 2007
> > @@ -184,6 +184,9 @@
> > public String crossJoinClause = "CROSS JOIN";
> > public boolean requiresConditionForCrossJoin = false;
> > public String forUpdateClause = "FOR UPDATE";
> > + public String optimizeClause = null;
> > + public String rowClause = "row";
> > + public String rowsClause = "rows";
> > public String tableForUpdateClause = null;
> > public String distinctCountColumnSeparator = null;
> > public boolean supportsSelectForUpdate = true;
> > @@ -2143,10 +2146,22 @@
> > SQLBuffer from, SQLBuffer where, SQLBuffer group,
> > SQLBuffer having, SQLBuffer order,
> > boolean distinct, boolean forUpdate, long start,
> long end) {
> > - return toOperation(getSelectOperation(fetch),
> > selects, from, where,
> > +
> > + String optimizeString = null;
> > + SQLBuffer selString =
> toOperation(getSelectOperation(fetch),
> > + selects, from, where,
> > group, having, order, distinct, forUpdate, start, end);
> > + if (fetch != null)
> > + optimizeString = getOptimizeClause(fetch);
> > + if (optimizeString != null)
> > + selString.append(optimizeString);
> > + return selString;
> > }
> >
> > + public String getOptimizeClause(JDBCFetchConfiguration fetch) {
> > + return null;
> > + }
> > +
> > /**
> > * Return the "SELECT" operation clause, adding any
> > available hints, etc.
> > */
> >
> > Modified:
> > incubator/openjpa/trunk/openjpa-kernel/src/main/java/org/apach
> e/openjpa/kernel/BrokerImpl.java
> > URL:
> > http://svn.apache.org/viewvc/incubator/openjpa/trunk/openjpa-k
> ernel/src/main/java/org/apache/openjpa/kernel/BrokerImpl.java?
> > view=diff&rev=510281&r1=510280&r2=510281
> > ==============================================================
> > ================
> > ---
> > incubator/openjpa/trunk/openjpa-kernel/src/main/java/org/apach
> e/openjpa/kernel/BrokerImpl.java (original)
> > +++
> > incubator/openjpa/trunk/openjpa-kernel/src/main/java/org/apach
> e/openjpa/kernel/BrokerImpl.java Wed Feb 21 14:50:04 2007
> > @@ -765,7 +765,7 @@
> > }
> > if (fetch == null)
> > fetch = _fc;
> > -
> > + fetch.setHint("openjpa.hint.optimize", new Integer(1));
> > beginOperation(true);
> > try {
> > assertNontransactionalRead();
> >
> > Modified:
> > incubator/openjpa/trunk/openjpa-persistence/src/main/java/org/
> apache/openjpa/persistence/QueryImpl.java
> > URL:
> > http://svn.apache.org/viewvc/incubator/openjpa/trunk/openjpa-p
> ersistence/src/main/java/org/apache/openjpa/persistence/QueryI
> mpl.java?> view=diff&rev=510281&r1=510280&r2=510281
> > ==============================================================
> > ================
> > ---
> > incubator/openjpa/trunk/openjpa-persistence/src/main/java/org/
> apache/openjpa/persistence/QueryImpl.java (original)
> > +++
> > incubator/openjpa/trunk/openjpa-persistence/src/main/java/org/
> apache/openjpa/persistence/QueryImpl.java Wed Feb 21 14:50:04 2007
> > @@ -279,6 +279,8 @@
> > */
> > public Object getSingleResult() {
> > _em.assertNotCloseInvoked();
> > + _query.getFetchConfiguration().
> > + setHint("openjpa.hint.optimize", new
> Integer(1));
> > Object ob = execute();
> > if (!(ob instanceof List))
> > return ob;
> >
> >
> >
