#382 - ENH: Add support for @History using Oracle Total Recall ... for 'as of' queries

src/main/java/com/avaje/ebean/config/dbplatform/DbHistorySupport.java

@@ -5,14 +5,32 @@ package com.avaje.ebean.config.dbplatform;
  */
 public interface DbHistorySupport {
 
+  /**
+   * Return true if the 'As of' predicate is part of the from clause
+   * (more standard sql2011). So true for Oracle total recall and false
+   * for Postgres and MySql (where we use views and history tables).
+   */
+  boolean isBindWithFromClause();
+
   /**
    * Return the number of columns bound in a 'As Of' predicate.
    * <p>
-   * Typically this is 2 but 1 for postgres using it's range type.
+   * This is 1 for more standard sql2011 style and Postgres which has the
+   * special range type and 2 for view based solutions with 2 columns such as
+   * MySql.
    * </p>
    */
   int getBindCount();
 
+  /**
+   * For sql2011 style this ignores the passed in view suffix and returns something
+   * like the ' as of timestamp ?' clause to be appended after the base table name.
+   *
+   * @param asOfViewSuffix the configured view suffix (typically "_with_history").
+   * @return The suffix appended after the base table name in the from and join clauses.
+   */
+  String getAsOfViewSuffix(String asOfViewSuffix);
+
   /**
    * Return the 'as of' predicate added for the given table alias.
    *
@@ -26,7 +44,7 @@ public interface DbHistorySupport {
    * Return the column for the system period lower bound that will be included in findVersions() queries.
    *
    * @param tableAlias the table alias which will typically be 't0'
-   * @param sysPeriod the name of the sys_period column
+   * @param sysPeriod  the name of the sys_period column
    */
   String getSysPeriodLower(String tableAlias, String sysPeriod);
 
@@ -34,7 +52,7 @@ public interface DbHistorySupport {
    * Return the column for the system period upper bound that will be included in findVersions() queries.
    *
    * @param tableAlias the table alias which will typically be 't0'
-   * @param sysPeriod the name of the sys_period column
+   * @param sysPeriod  the name of the sys_period column
    */
   String getSysPeriodUpper(String tableAlias, String sysPeriod);
 

src/main/java/com/avaje/ebean/config/dbplatform/DbStandardHistorySupport.java

@@ -0,0 +1,32 @@
+package com.avaje.ebean.config.dbplatform;
+
+/**
+ * SQL2011 based history support using 'as of timestamp' type clause appended as part of the the from or join clause.
+ */
+public abstract class DbStandardHistorySupport implements DbHistorySupport {
+
+  /**
+   * Return true as with sql2011 the 'as of timestamp' clause included in from or join clause.
+   */
+  @Override
+  public boolean isBindWithFromClause() {
+    return true;
+  }
+
+  /**
+   * Return 1 as the bind count (not 2 for effective start and effective end columns).
+   */
+  @Override
+  public int getBindCount() {
+    return 1;
+  }
+
+  /**
+   * Return null - not used for sql2011 based history.
+   */
+  @Override
+  public String getAsOfPredicate(String tableAlias, String sysPeriod) {
+    // not used for sql2011 based history
+    return null;
+  }
+}

src/main/java/com/avaje/ebean/config/dbplatform/DbViewHistorySupport.java

@@ -0,0 +1,71 @@
+package com.avaje.ebean.config.dbplatform;
+
+/**
+ * Database view based implementation of DbHistorySupport.
+ * <p>
+ * These implementations have explicit history tables, a view to union the
+ * base table and history table and triggers to maintain the history.
+ * </p>
+ */
+public abstract class DbViewHistorySupport implements DbHistorySupport {
+
+  /**
+   * Return false for view based implementations where we append extra 'as of' predicates to the end.
+   */
+  @Override
+  public boolean isBindWithFromClause() {
+    return false;
+  }
+
+  /**
+   * Returns the configured view suffix.
+   *
+   * @param asOfViewSuffix the configured view suffix (typically "_with_history").
+   */
+  @Override
+  public String getAsOfViewSuffix(String asOfViewSuffix) {
+    // just return the configured suffix
+    return asOfViewSuffix;
+  }
+
+  /**
+   * Return 2 if we have effective start and effective end as 2 columns.
+   * Note that for postgres we can use a single range type so that returns 1.
+   */
+  @Override
+  public int getBindCount() {
+    return 2;
+  }
+
+  /**
+   * Return the 'as of' predicate clause appended to the end of the normal query predicates.
+   */
+  @Override
+  public String getAsOfPredicate(String asOfTableAlias, String asOfSysPeriod) {
+
+    // (sys_period_start < ? and (sys_period_end is null or sys_period_end > ?));
+    return "(" + asOfTableAlias + "." + asOfSysPeriod + "_start" + " < ? and (" + asOfTableAlias + "." + asOfSysPeriod + "_end" + " is null or " + asOfTableAlias + "." + asOfSysPeriod + "_end" + " > ?))";
+  }
+
+  /**
+   * Return the lower bound column prepended with the table alias.
+   *
+   * @param tableAlias the table alias
+   * @param sysPeriod  the name of the sys_period column
+   */
+  @Override
+  public String getSysPeriodLower(String tableAlias, String sysPeriod) {
+    return tableAlias + "." + sysPeriod + "_start";
+  }
+
+  /**
+   * Return the upper bound column prepended with the table alias.
+   *
+   * @param tableAlias the table alias
+   * @param sysPeriod  the name of the sys_period column
+   */
+  @Override
+  public String getSysPeriodUpper(String tableAlias, String sysPeriod) {
+    return tableAlias + "." + sysPeriod + "_end";
+  }
+}

src/main/java/com/avaje/ebean/config/dbplatform/MySqlHistorySupport.java

@@ -3,33 +3,7 @@ package com.avaje.ebean.config.dbplatform;
 /**
  * Runtime support for @History with MySql.
  */
-public class MySqlHistorySupport implements DbHistorySupport {
+public class MySqlHistorySupport extends DbViewHistorySupport {
 
-  @Override
-  public int getBindCount() {
-    return 2;
-  }
 
-  @Override
-  public String getAsOfPredicate(String asOfTableAlias, String asOfSysPeriod) {
-
-    StringBuilder sb = new StringBuilder(90);
-    sb.append("(");
-    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_start").append(" < ? and (");
-    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_end").append(" is null or ");
-    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_end").append(" > ?))");
-
-    // (sys_period_start < ? and (sys_period_end is null or sys_period_end > ?));
-    return sb.toString();
-  }
-
-  @Override
-  public String getSysPeriodLower(String tableAlias, String sysPeriod) {
-    return tableAlias+"."+sysPeriod+"_start";
-  }
-
-  @Override
-  public String getSysPeriodUpper(String tableAlias, String sysPeriod) {
-    return tableAlias+"."+sysPeriod+"_end";
-  }
 }

src/main/java/com/avaje/ebean/config/dbplatform/Oracle10Platform.java

@@ -21,6 +21,7 @@ public class Oracle10Platform extends DatabasePlatform {
     this.dbEncrypt = new Oracle10DbEncrypt();
     this.sqlLimiter = new RownumSqlLimiter();
     this.platformDdl = new Oracle10Ddl(this.dbTypeMap, this.dbIdentity);
+    this.historySupport = new OracleDbHistorySupport();
 
     // Not using getGeneratedKeys as instead we will
     // batch load sequences which enables JDBC batch execution

src/main/java/com/avaje/ebean/config/dbplatform/OracleDbHistorySupport.java

@@ -0,0 +1,32 @@
+package com.avaje.ebean.config.dbplatform;
+
+/**
+ * Oracle Total recall based history support.
+ */
+public class OracleDbHistorySupport extends DbStandardHistorySupport {
+
+  /**
+   * Return the ' as of timestamp ?' clause appended after the table name.
+   */
+  @Override
+  public String getAsOfViewSuffix(String asOfViewSuffix) {
+    return " as of TIMESTAMP ?";
+  }
+
+  /**
+   * Returns the Oracle specific effective start column.
+   */
+  @Override
+  public String getSysPeriodLower(String tableAlias, String sysPeriod) {
+    return "versions_starttime";
+  }
+
+  /**
+   * Returns the Oracle specific effective end column.
+   */
+  @Override
+  public String getSysPeriodUpper(String tableAlias, String sysPeriod) {
+    return "versions_endtime";
+  }
+
+}

src/main/java/com/avaje/ebean/config/dbplatform/PostgresHistorySupport.java

@@ -3,10 +3,10 @@ package com.avaje.ebean.config.dbplatform;
 /**
  * Postgres support for history features.
  */
-public class PostgresHistorySupport implements DbHistorySupport {
+public class PostgresHistorySupport extends DbViewHistorySupport {
 
   /**
-   * Return 1 as we are using the range type and hence don't need 2 bind variables.
+   * Return 1 as we are using the postgres range type and hence don't need 2 bind variables.
    */
   @Override
   public int getBindCount() {
@@ -24,19 +24,16 @@ public class PostgresHistorySupport implements DbHistorySupport {
 
     // for Postgres we are using the 'timestamp with timezone range' data type
     // as our sys_period column so hence the predicate below
-    //noinspection StringBufferReplaceableByString
-    StringBuilder sb = new StringBuilder(40);
-    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append(" @> ?::timestamptz");
-    return sb.toString();
+    return asOfTableAlias + "." + asOfSysPeriod + " @> ?::timestamptz";
   }
 
   @Override
   public String getSysPeriodLower(String tableAlias, String sysPeriod) {
-    return "lower("+tableAlias+"."+sysPeriod+")";
+    return "lower(" + tableAlias + "." + sysPeriod + ")";
   }
 
   @Override
   public String getSysPeriodUpper(String tableAlias, String sysPeriod) {
-    return "upper("+tableAlias+"."+sysPeriod+")";
+    return "upper(" + tableAlias + "." + sysPeriod + ")";
   }
 }

src/main/java/com/avaje/ebeaninternal/server/core/InternalConfiguration.java

@@ -122,7 +122,7 @@ public class InternalConfiguration {
 
     DatabasePlatform databasePlatform = serverConfig.getDatabasePlatform();
 
-    this.binder = new Binder(typeManager, getAsOfBindCount(databasePlatform));
+    this.binder = getBinder(typeManager, databasePlatform);
     this.cQueryEngine = new CQueryEngine(databasePlatform, binder, asOfTableMapping, serverConfig.getAsOfSysPeriod());
 
     ExternalTransactionManager externalTransactionManager = serverConfig.getExternalTransactionManager();
@@ -142,9 +142,12 @@ public class InternalConfiguration {
   /**
    * For 'As Of' queries return the number of bind variables per predicate.
    */
-  private int getAsOfBindCount(DatabasePlatform databasePlatform) {
+  private Binder getBinder(TypeManager typeManager, DatabasePlatform databasePlatform) {
     DbHistorySupport historySupport = databasePlatform.getHistorySupport();
-    return historySupport == null ? 0 : historySupport.getBindCount();
+    if (historySupport == null) {
+      return new Binder(typeManager, 0, false);
+    }
+    return new Binder(typeManager, historySupport.getBindCount(), historySupport.isBindWithFromClause());
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -12,6 +12,7 @@ import com.avaje.ebean.config.EncryptKeyManager;
 import com.avaje.ebean.config.NamingConvention;
 import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.config.dbplatform.DatabasePlatform;
+import com.avaje.ebean.config.dbplatform.DbHistorySupport;
 import com.avaje.ebean.config.dbplatform.DbIdentity;
 import com.avaje.ebean.config.dbplatform.IdGenerator;
 import com.avaje.ebean.config.dbplatform.IdType;
@@ -174,7 +175,7 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
     this.idBinderFactory = new IdBinderFactory(databasePlatform.isIdInExpandedForm());
     this.eagerFetchLobs = serverConfig.isEagerFetchLobs();
 
-    this.asOfViewSuffix = serverConfig.getAsOfViewSuffix();
+    this.asOfViewSuffix = getAsOfViewSuffix(databasePlatform, serverConfig);
     this.readAnnotations = new ReadAnnotations(config.getGeneratedPropertyFactory(), asOfViewSuffix);
     this.bootupClasses = config.getBootupClasses();
     this.createProperties = config.getDeployCreateProperties();
@@ -199,6 +200,17 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
     this.transientProperties = new TransientProperties();
   }
 
+  /**
+   * Return the AsOfViewSuffix allowing the DbHistorySupport to override the value in
+   * the case where there is no view (Oracle, DB2, MS SQL Server).
+   */
+  private String getAsOfViewSuffix(DatabasePlatform databasePlatform, ServerConfig serverConfig) {
+
+    DbHistorySupport historySupport = databasePlatform.getHistorySupport();
+    // with historySupport returns a simple view suffix or the sql2011 as of timestamp suffix
+    return (historySupport == null ) ? serverConfig.getAsOfViewSuffix() : historySupport.getAsOfViewSuffix(serverConfig.getAsOfViewSuffix());
+  }
+
   public BeanDescriptor<?> getBeanDescriptorById(String descriptorId) {
     return idDescMap.get(descriptorId);
   }

src/main/java/com/avaje/ebeaninternal/server/persist/Binder.java

@@ -28,12 +28,15 @@ public class Binder {
 
   private final int asOfBindCount;
 
+  private final boolean bindAsOfWithFromClause;
+
   /**
    * Set the PreparedStatement with which to bind variables to.
    */
-  public Binder(TypeManager typeManager, int asOfBindCount) {
+  public Binder(TypeManager typeManager, int asOfBindCount, boolean bindAsOfWithFromClause) {
     this.typeManager = typeManager;
     this.asOfBindCount = asOfBindCount;
+    this.bindAsOfWithFromClause = bindAsOfWithFromClause;
   }
 
   /**
@@ -43,6 +46,15 @@ public class Binder {
     return asOfBindCount;
   }
 
+  /**
+   * Return true if the 'as of' predicates are in the from/join clause in which case the timestamp is
+   * bound early (before all the other predicates ala Oracle). Return false if the 'as of' predicates are
+   * appended to the end of the predicates and the timestamp is bound last (Postgres, MySql).
+   */
+  public boolean isBindAsOfWithFromClause() {
+    return bindAsOfWithFromClause;
+  }
+
   /**
    * Bind the values to the Prepared Statement.
    */

src/main/java/com/avaje/ebeaninternal/server/query/CQueryBuilder.java

@@ -403,9 +403,10 @@ public class CQueryBuilder {
     }
 
     List<String> asOfTableAlias = query.getAsOfTableAlias();
-    if (asOfTableAlias != null) {
+    if (asOfTableAlias != null && !historySupport.isBindAtFromClause()) {
       // append the effective date predicates for each table alias
       // that maps to a @History entity involved in this query
+      // Do this when history using separate tables/views (PG, MySql etc)
       if (!hasWhere) {
         sb.append(" where ");
       } else {

src/main/java/com/avaje/ebeaninternal/server/query/CQueryHistorySupport.java

@@ -30,22 +30,42 @@ public class CQueryHistorySupport {
     this.sysPeriod = sysPeriod;
   }
 
+  /**
+   * Return true if the bind of 'as of' timestamp occurs with the from clause
+   * rather than at the end.
+   */
+  public boolean isBindAtFromClause() {
+    return dbHistorySupport.isBindWithFromClause();
+  }
+
+  /**
+   * Return the 'as of' history view for the given base table.
+   */
   public String getAsOfView(String table) {
     return asOfTableMap.get(table);
   }
 
+  /**
+   * Return the lower bound column.
+   */
   public String getSysPeriodLower(String tableAlias) {
-
     return dbHistorySupport.getSysPeriodLower(tableAlias, sysPeriod);
   }
 
+  /**
+   * Return the upper bound column.
+   */
   public String getSysPeriodUpper(String tableAlias) {
-
     return dbHistorySupport.getSysPeriodUpper(tableAlias, sysPeriod);
   }
 
+  /**
+   * Return the predicate appended to the end of the query.
+   *
+   * Note used for Oracle total recall etc with the more standard approach.
+   */
   public String getAsOfPredicate(String tableAlias) {
-
     return dbHistorySupport.getAsOfPredicate(tableAlias, sysPeriod);
   }
+
 }

src/main/java/com/avaje/ebeaninternal/server/query/CQueryPredicates.java

@@ -131,6 +131,18 @@ public class CQueryPredicates {
 
     StringBuilder bindLog = new StringBuilder();
 
+    List<String> historyTableAlias = query.getAsOfTableAlias();
+    if (historyTableAlias != null && binder.isBindAsOfWithFromClause()) {
+      // bind the asOf value for each table alias as part of the from/join clauses
+      // there is one effective date predicate per table alias
+      Timestamp asOf = query.getAsOf();
+      bindLog.append("asOf ").append(asOf);
+      for (int i = 0; i < historyTableAlias.size() * binder.getAsOfBindCount(); i++) {
+        binder.bindObject(dataBind, asOf);
+      }
+      bindLog.append(", ");
+    }
+
     if (idValue != null) {
       // this is a find by id type query...
       request.getBeanDescriptor().bindId(dataBind, idValue);
@@ -143,7 +155,6 @@ public class CQueryPredicates {
     }
 
     if (whereExprBindValues != null) {
-
       for (int i = 0; i < whereExprBindValues.size(); i++) {
         Object bindValue = whereExprBindValues.get(i);
         bindValue = binder.bindObject(dataBind, bindValue);
@@ -155,7 +166,6 @@ public class CQueryPredicates {
     }
 
     if (filterManyExprBindValues != null) {
-
       for (int i = 0; i < filterManyExprBindValues.size(); i++) {
         Object bindValue = filterManyExprBindValues.get(i);
         bindValue = binder.bindObject(dataBind, bindValue);
@@ -166,9 +176,8 @@ public class CQueryPredicates {
       }
     }
 
-    List<String> historyTableAlias = query.getAsOfTableAlias();
-    if (historyTableAlias != null) {
-      // bind the asAt value for each table alias
+    if (historyTableAlias != null && !binder.isBindAsOfWithFromClause()) {
+      // bind the asOf value for each table alias after all the normal predicates
       // there is one effective date predicate per table alias
       Timestamp asOf = query.getAsOf();
       bindLog.append(" asOf ").append(asOf);