自动休眠索引创建时间过长答案

【问题标题】：Automatic Hibernate index creation too long自动休眠索引创建时间过长
【发布时间】：2017-04-08 11:37:30
【问题描述】：

我回来时遇到了一个现在暴露在阳光下的错误/问题。通常我会在 H2DB 上测试本地开发和更改，但据我所知，这也必须在 Oracle 和 MSSQL 上运行。现在再次在oracle上测试出现这个问题：键 COR_VIEWSETTINGSCOR_USERSETTINGS_FK0 和 COR_VIEWSETTINGSCOR_USERSETTINGS_FK1 是自动生成的，对于 oracle 数据库来说太长了。要了解这些键是如何创建的，我现在将向您展示实体 UserSettings 和 UserViewSettings。提示：如果实体让您感到困惑，您可以忽略这些实体并进一步进行编辑。也许你还能帮助我。

用户设置

/**

      The Class UserSettings.

*/
@org.hibernate.envers.Audited
@DataObject( value =  UserSettings.DATA_OBJECT_NAME )
@CRUDDefinition( supportsRead = true, supportsCreate = true, supportsUpdate = true, supportsDelete = true )
@Entity( name = UserSettings.DATA_OBJECT_NAME )
@NamedQuery( name = UserSettings.DATA_OBJECT_NAME, query = "from userSettings e where e.name = :name" )
@javax.persistence.Inheritance( strategy = javax.persistence.InheritanceType.TABLE_PER_CLASS )
@AttributeOverrides( { @AttributeOverride( name = "id", column = @Column( name = "USERSETTINGS_ID" ) )
} )
@Table( name = "COR_USERSETTINGS", indexes = {
  @javax.persistence.Index( name="COR_USERSETTINGS_FK0", columnList = "SETTINGSTYPE_ID" ),
  @javax.persistence.Index( name="COR_USERSETTINGS_FK1", columnList = "USER_ID" ),
}
)
public class UserSettings extends NamedRevisionEntity implements NameSettingsType, NameSettings
{
  /** The Constant serialVersionUID. */
  private static final long serialVersionUID = 1L;

  /** The Constant DATA_OBJECT_NAME. */
  public static final String DATA_OBJECT_NAME = "userSettings";

  @javax.persistence.Basic( fetch = javax.persistence.FetchType.EAGER, optional = false )
  @Column( name = "SETTINGS", nullable = false, unique = false, insertable = true, updatable = true )
  @javax.persistence.Lob
  private java.lang.String settings;

  @javax.persistence.ManyToOne( fetch = javax.persistence.FetchType.EAGER, optional = false )
  @javax.persistence.JoinColumn( name = "SETTINGSTYPE_ID", nullable = false, unique = false, insertable = true, updatable = true )
  private SettingsType settingsType;

  @javax.persistence.ManyToOne( fetch = javax.persistence.FetchType.EAGER, optional = true )
  @javax.persistence.JoinColumn( name = "USER_ID", nullable = true, unique = false, insertable = true, updatable = true )
  private User user;



  public SettingsType getSettingsType()
  {
    return settingsType;
  }

  public void setSettingsType( SettingsType settingsType )
  {
    this.settingsType = settingsType;
  }

  public User getUser()
  {
    return user;
  }

  public void setUser( User user )
  {
    this.user = user;
  }

  public java.lang.String getSettings()
  {
    return settings;
  }

  public void setSettings( java.lang.String settings )
  {
    this.settings = settings;
  }

  @Override
  public String getDataObjectName()
  {
    return DATA_OBJECT_NAME;
  }



  @Override
  public String toString()
  {
    StringBuilder builder = new StringBuilder( super.toString() );

    builder.append( ", " );
    try
    {
        builder.append( ToStringUtils.referenceToString( "settingsType", "SettingsType", this.settingsType ) );
    }
    catch( Exception ex )
    {
      builder.append( ex.getClass().getName()  );
      builder.append( ": " );
      builder.append( ex.getMessage() );
    }
    builder.append( ", " );
    try
    {
        builder.append( ToStringUtils.referenceToString( "user", "User", this.user ) );
    }
    catch( Exception ex )
    {
      builder.append( ex.getClass().getName()  );
      builder.append( ": " );
      builder.append( ex.getMessage() );
    }

    builder.append( "]" );
    return builder.toString();
  }

}

用户视图设置

/**

      The Class UserViewSettings.

*/
@org.hibernate.envers.Audited
@DataObject( value =  UserViewSettings.DATA_OBJECT_NAME )
@CRUDDefinition( supportsRead = true, supportsCreate = true, supportsUpdate = true, supportsDelete = true )
@Entity( name = UserViewSettings.DATA_OBJECT_NAME )
@AttributeOverrides( { @AttributeOverride( name = "id", column = @Column( name = "VIEWSETTINGS_ID" ) )
} )
@Table( name = "COR_VIEWSETTINGS", uniqueConstraints = {
  @javax.persistence.UniqueConstraint( name="COR_VIEWSETTINGS_UNQ1", columnNames = { "NAME", "SETTINGSTYPE_ID", "VIEW_NAME", "VIEWTYPE_ID" } ),
}
, indexes = {
  @javax.persistence.Index( name="COR_VIEWSETTINGS_FK0", columnList = "VIEWTYPE_ID" ),
}
)
public class UserViewSettings extends UserSettings implements NameViewName, NameViewType
{
  /** The Constant serialVersionUID. */
  private static final long serialVersionUID = 1L;

  /** The Constant DATA_OBJECT_NAME. */
  public static final String DATA_OBJECT_NAME = "userViewSettings";

  @javax.persistence.Basic( fetch = javax.persistence.FetchType.EAGER, optional = false )
  @Column( name = "VIEW_NAME", nullable = false, unique = false, insertable = true, updatable = true )
  private java.lang.String viewName;

  @javax.persistence.ManyToOne( fetch = javax.persistence.FetchType.EAGER, optional = true )
  @javax.persistence.JoinColumn( name = "VIEWTYPE_ID", nullable = true, unique = false, insertable = true, updatable = true )
  private ViewType viewType;



  public java.lang.String getViewName()
  {
    return viewName;
  }

  public void setViewName( java.lang.String viewName )
  {
    this.viewName = viewName;
  }

  public ViewType getViewType()
  {
    return viewType;
  }

  public void setViewType( ViewType viewType )
  {
    this.viewType = viewType;
  }

  @Override
  public String getDataObjectName()
  {
    return DATA_OBJECT_NAME;
  }



  @Override
  public String toString()
  {
    StringBuilder builder = new StringBuilder( super.toString() );

    builder.append( ", " );
    builder.append( "viewName" );
    builder.append( "=" );
    builder.append( this.viewName );
    builder.append( ", " );
    try
    {
        builder.append( ToStringUtils.referenceToString( "viewType", "ViewType", this.viewType ) );
    }
    catch( Exception ex )
    {
      builder.append( ex.getClass().getName()  );
      builder.append( ": " );
      builder.append( ex.getMessage() );
    }

    builder.append( "]" );
    return builder.toString();
  }

}

使用 Hibernate 5.2 和 Oracle 11 数据库启动 Wildfly 10.0.0 然后会导致错误自动生成的密钥 COR_VIEWSETTINGSCOR_USERSETTINGS_FK0 和 COR_VIEWSETTINGSCOR_USERSETTINGS_FK1 对于数据库来说自然太长了.

我查看了 Hibernate 的 NamingStrategies，甚至尝试了一些，但它们并没有为我改变错误。

如何影响这些密钥的生成？

编辑：

所以打开 DEBUG 给了我这个：

2016-11-29 09:22:03,190 DEBUG [org.hibernate.SQL] (ServerService Thread Pool -- 58) create index COR_USERSETTINGS_FK0 on COR_USERSETTINGS (SETTINGSTYPE_ID)
2016-11-29 09:22:03,190 DEBUG [org.hibernate.SQL] (ServerService Thread Pool -- 58) create index COR_USERSETTINGS_FK1 on COR_USERSETTINGS (USER_ID)
2016-11-29 09:22:03,190 DEBUG [org.hibernate.SQL] (ServerService Thread Pool -- 58) create index COR_VIEWSETTINGSCOR_USERSETTINGS_FK0 on COR_VIEWSETT INGS(SETTINGSTYPE_ID)
2016-11-29 09:22:03,190 DEBUG [org.hibernate.SQL] (ServerService Thread Pool -- 58) create index COR_VIEWSETTINGSCOR_USERSETTINGS_FK1 on COR_VIEWSETTINGS (USER_ID)
2016-11-29 09:22:03,190 DEBUG [org.hibernate.SQL] (ServerService Thread Pool -- 58) create index COR_VIEWSETTINGS_FK0 on COR_VIEWSETTINGS (VIEWTYPE_ID)

现在我在包 org.hibernate.boot.model.naming 中找到了类 ImplicitIndexNameSource 但互联网并没有真正给出我可以用它做什么的例子而且好像是很久很久以前的空班。

编辑 2：

以前的编辑似乎是错误的路径。我找到了创建这些日志的地方。它是从 SchemaCreatorImpl 调用的 StandardIndexExporter。所以我需要更深入地研究这个框架，但如果有人看到了。这是正确的道路吗？我可以修改代码，让他做我想做的事吗？似乎是 hbm2ddl 是罪魁祸首，因为索引 get 是在 StandardIndexExport 中在这些行中创建的：

final String indexNameForCreation;
if ( dialect.qualifyIndexName() ) {
    indexNameForCreation = jdbcEnvironment.getQualifiedObjectNameFormatter().format(
            new QualifiedNameImpl(
                    index.getTable().getQualifiedTableName().getCatalogName(),
                    index.getTable().getQualifiedTableName().getSchemaName(),
                    jdbcEnvironment.getIdentifierHelper().toIdentifier( index.getName() )
            ),
            jdbcEnvironment.getDialect()
    );
}
else {
    indexNameForCreation = index.getName();
}
final StringBuilder buf = new StringBuilder()
        .append( "create index " )
        .append( indexNameForCreation )
        .append( " on " )
        .append( tableName )
        .append( " (" );

boolean first = true;
Iterator<Column> columnItr = index.getColumnIterator();
while ( columnItr.hasNext() ) {
    final Column column = columnItr.next();
    if ( first ) {
        first = false;
    }
    else {
        buf.append( ", " );
    }
    buf.append( ( column.getQuotedName( dialect ) ) );
}
buf.append( ")" );
return new String[] { buf.toString() };

非常感谢您的帮助。这真是令人沮丧

【问题讨论】：

标签： java oracle hibernate hbm2ddl

【解决方案1】：

所以我让它工作了。为将来可能会发现此问题并遇到相同问题的人回答。

索引键是由 hibernate 引用的 oracle 方言创建的。所以必须做的是实现一个自定义的 OracleDialect，覆盖方法 getIndexExporter 并指向自定义的 IndexExporter。然后，您可以在此 IndexExporter 中修改创建键的方式。就我而言，我修复了这样的解决方案：

  /**
   * Gets the correct index name if it is a index for a TABLE_PER_CLASS inheritance and longer than
   * 30 chars.
   *
   * @param index the index to decide for
   * @return the correct index name
   */
  private String getCorrectIndexName( Index index )
  {
    if ( index.getTable() instanceof DenormalizedTable && index.getName().length() > 30 )
    {
      String prefixedTable = index.getTable().getName();
      String tableName = prefixedTable.substring( prefixedTable.indexOf( '_' ) + 1, prefixedTable.length() );
      tableName = shortenName( tableName );
      Iterator<Column> columnItr = index.getColumnIterator();
      String reference;

      if ( columnItr.hasNext() )
      {
        reference = extractReference( columnItr.next() );
      }
      else
      {
        /** backup strategy to prevent exceptions */
        reference = shortenName( NamingHelper.INSTANCE.hashedName( index.getName() ) );
      }

      return tableName + "_" + reference;
    }
    return index.getName();
  }

  /**
   * Extract the reference column of the index and hash the full name before shortening it with
   * shortenName().
   *
   * @param index the index to extract the reference from.
   * @return the reference with an appended _FK(hashedReference).
   */
  private String extractReference( Column column )
  {
    String reference = column.getQuotedName( dialect );
    String md5Hash = NamingHelper.INSTANCE.hashedName( reference );
    md5Hash = md5Hash.substring( md5Hash.length() - 4, md5Hash.length() );
    reference = shortenName( reference );

    return reference + "_FK" + md5Hash;
  }

  /**
   * Shorten the name to a maximum of 11 chars if it's longer.
   *
   * @param reference the reference to shorten
   * @return the shortened string
   */
  private static String shortenName( String reference )
  {
    if ( reference.length() > 11 )
    {
      return reference.substring( 0, 11 );
    }
    return reference;
  }

这必须在重写函数 getSqlCreateStrings 中调用。更改后的行如下所示：

  String indexName = getCorrectIndexName( index );
  indexNameForCreation = jdbcEnvironment.getQualifiedObjectNameFormatter()
      .format(
          new QualifiedNameImpl( index.getTable().getQualifiedTableName().getCatalogName(),
              index.getTable().getQualifiedTableName().getSchemaName(), jdbcEnvironment.getIdentifierHelper().toIdentifier( indexName ) ),
          jdbcEnvironment.getDialect() );

我希望对某人有所帮助。

【讨论】：