From fe62c9f1600e15ce6751718539704f56ad1faaec Mon Sep 17 00:00:00 2001
From: rk <rk>
Date: Sun, 17 Feb 2002 23:30:22 +0000
Subject: [PATCH] select count optimization...

---
 source/mir/entity/EntityRelation.java | 14 -------
 source/mir/storage/Database.java      | 69 ++++++++++++++++++++++-------------
 2 files changed, 44 insertions(+), 39 deletions(-)

diff --git a/source/mir/entity/EntityRelation.java b/source/mir/entity/EntityRelation.java
index 5fe44f9d..272a7de8 100755
--- a/source/mir/entity/EntityRelation.java
+++ b/source/mir/entity/EntityRelation.java
@@ -45,20 +45,6 @@ public class EntityRelation {
   }
 
   /**
-   *   @return Liefert ein freemarker.template.SimpleHash mit den verknuepften
-   *           Entities, wenn es sich um eine TO_ONE Beziehung handelt, ansonsten
-   *           null.
-   */
-
-  public SimpleHash getOneAsSimpleHash(Entity entity) throws StorageObjectException {
-    if (type==TO_ONE) {
-        Entity returnEntity = getOne(entity);
-        if (returnEntity!=null) return HTMLTemplateProcessor.makeSimpleHash(returnEntity);
-    }
-    return null;
-  }
-
-  /**
    *   @return Liefert eine freemarker.template.SimpleList mit den verknuepften
    *           Entities, wenn es sich um eine TO_MANY Liste handelt, ansonsten
    *           null.
diff --git a/source/mir/storage/Database.java b/source/mir/storage/Database.java
index b8d5f59c..5c40ac21 100755
--- a/source/mir/storage/Database.java
+++ b/source/mir/storage/Database.java
@@ -435,21 +435,21 @@ public class Database implements StorageObject {
       con = getPooledCon();
       stmt = con.createStatement();
       // counting rows
-      if (theAdaptor.hasLimit()) {
-        rs = executeSql(stmt, countSql.toString());
-        if (rs != null) {
-          if (rs.next())
-            count = rs.getInt(1);
-          rs.close();
-          //nothing in the table: return null
-          if(count<=0){
-            freeConnection(con, stmt);
-            return null;
-          }
-        } else {
-          theLog.printError("Could not count: " + countSql);
-        }
-      }
+
+      /** @todo select count(*) should be optimized:
+       *  1. it should take place after select statement because in some
+       *     cases it is not necessary anymore.
+       *  2. it is only needed if entitylist needs information about how
+       *     many datasets there are overall
+       *
+       *  optimization:
+       *
+       *  if we manage to have the full information about allData already
+       *  with the select statement, then we set it in entitylist, other
+       *  wise we fetch it.  /rk
+       *  */
+
+
 
       // hier select
       rs = executeSql(stmt, selectSql.toString());
@@ -466,11 +466,26 @@ public class Database implements StorageObject {
         }
         rs.close();
       }
-      // making entitylist
-      if (!(theAdaptor.hasLimit()))
-        count = offsetCount;
+
+      // making entitylist infos
+      if (!(theAdaptor.hasLimit())) count = offsetCount;
+
       if (theReturnList != null) {
+        // now we decide if we have to know an overall count...
+        count=offsetCount;
+        if (limit > -1 && offset > -1) {
+          if (offsetCount==limit) {
+            rs = executeSql(stmt, countSql.toString());
+            if (rs != null) {
+              if ( rs.next() ) count = rs.getInt(1);
+              rs.close();
+            }
+            else theLog.printError("Could not count: " + countSql);
+          }
+        }
+
         theReturnList.setCount(count);
+
         theReturnList.setOffset(offset);
         theReturnList.setWhere(wc);
         theReturnList.setOrder(ob);
@@ -480,6 +495,9 @@ public class Database implements StorageObject {
         if (offset + offsetCount < count) {
           theReturnList.setNextBatch(offset + limit);
         }
+
+
+
       }
     } catch (SQLException sqe) {
       throwSQLException(sqe, "selectByWhereClause");
@@ -489,6 +507,7 @@ public class Database implements StorageObject {
     return  theReturnList;
   }
 
+
   /**
    *  Bastelt aus einer Zeile der Datenbank ein EntityObjekt.
    *
@@ -496,7 +515,7 @@ public class Database implements StorageObject {
    *  @return Entity Die Entity.
    */
 
-  public Entity makeEntityFromResultSet (ResultSet rs) throws StorageObjectException {
+  private Entity makeEntityFromResultSet (ResultSet rs) throws StorageObjectException {
     HashMap theResultHash = new HashMap();
     String theResult = null;
     int theType;
@@ -817,7 +836,7 @@ public class Database implements StorageObject {
     try {
       con = getPooledCon();
     } catch (Exception e) {
-      throw new StorageObjectException(e.toString()); 
+      throw new StorageObjectException(e.toString());
     }
     try {
       stmt = con.createStatement();
@@ -843,7 +862,7 @@ public class Database implements StorageObject {
       }
     } catch (Exception e) {
       theLog.printError("getPopupData: "+e.toString());
-      throw new StorageObjectException(e.toString()); 
+      throw new StorageObjectException(e.toString());
     } finally {
       freeConnection(con, stmt);
     }
@@ -967,7 +986,7 @@ public class Database implements StorageObject {
     }
     catch (SQLException e)
     {
-      theLog.printDebugInfo("Failed: " + (new java.util.Date().getTime() 
+      theLog.printDebugInfo("Failed: " + (new java.util.Date().getTime()
                             - startTime) + "ms. for: "+ sql);
       throw e;
     }
@@ -1052,7 +1071,7 @@ public class Database implements StorageObject {
     }
   }
 
-  
+
   public Connection getPooledCon() throws StorageObjectException {
     /* @todo , doublecheck but I'm pretty sure that this is unnecessary. -mh
       try{
@@ -1072,7 +1091,7 @@ public class Database implements StorageObject {
     }
     return con;
   }
- 
+
   public void freeConnection (Connection con, Statement stmt)
     throws StorageObjectException {
     SQLManager.getInstance().closeStatement(stmt);
@@ -1114,7 +1133,7 @@ public class Database implements StorageObject {
   }
 
   /**
-   * Loggt Fehlermeldung mit dem Parameter Message und wirft dannach 
+   * Loggt Fehlermeldung mit dem Parameter Message und wirft dannach
    * eine StorageObjectException
    * @param message Nachricht mit dem Fehler
    * @exception StorageObjectException
-- 
2.11.0