Creating Indexes on DB with Hibernate @Index Annotation

Question

I have annotation-driven hibernate capabilies on my project.

Now I want to create an index over a column. My current column definition is

@NotNull
@C         


        

Answer 1

Index creation on schema update was intentionally disabled in Hibernate because it seemed inconsistent with the naming used in the schema export.

This is the commented code that you can find in class org.hibernate.cfg.Configuration.

//broken, 'cos we don't generate these with names in SchemaExport
subIter = table.getIndexIterator();
while ( subIter.hasNext() ) {
    Index index = (Index) subIter.next();
    if ( !index.isForeignKey() || !dialect.hasImplicitIndexForForeignKey() ) {
        if ( tableInfo==null || tableInfo.getIndexMetadata( index.getFilterName() ) == null ) {
            script.add( index.sqlCreateString(dialect, mapping) );
        }
    }
}
//broken, 'cos we don't generate these with names in SchemaExport
subIter = table.getUniqueKeyIterator();
while ( subIter.hasNext() ) {
    UniqueKey uk = (UniqueKey) subIter.next();
    if ( tableInfo==null || tableInfo.getIndexMetadata( uk.getFilterName() ) == null ) {
        script.add( uk.sqlCreateString(dialect, mapping) );
    }
}

Usually I remove that comment, recompile Hibernate.jar and have indexes created on schema update without any problem, at least with Oracle DB.

In recent versions of Hibernate the comment on the first part (table indexes) has been removed in the official version as well, while it's still commented the second one (indexes that implement unique keys). See the discussion at http://opensource.atlassian.com/projects/hibernate/browse/HHH-1012