From f5c7c0fe099bafc81bf8d2d4d4529c605a2c8682 Mon Sep 17 00:00:00 2001
From: phib <devnull@localhost>
Date: Thu, 19 Nov 2009 22:13:57 +0000
Subject: [PATCH] 2900767 Zoom to child tab - inefficient queries
 https://sourceforge.net/tracker/?func=detail&aid=2900767&group_id=176962&atid=879332

---
 base/src/org/compiere/model/GridTab.java | 12 ++++++++----
 base/src/org/compiere/util/DB.java       |  8 +++++---
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/base/src/org/compiere/model/GridTab.java b/base/src/org/compiere/model/GridTab.java
index 1b9574a9e7..09013eafbc 100644
--- a/base/src/org/compiere/model/GridTab.java
+++ b/base/src/org/compiere/model/GridTab.java
@@ -87,6 +87,8 @@ import org.compiere.util.ValueNamePair;
  *  @see  http://sourceforge.net/tracker/?func=detail&atid=879335&aid=1877902&group_id=176962 to FR [1877902]
  *  @author Cristina Ghita, www.arhipac.ro FR [2870645] Set null value for an ID
  *  @see  https://sourceforge.net/tracker/?func=detail&atid=879335&aid=2870645&group_id=176962
+ *  @author Paul Bowden, phib BF 2900767 Zoom to child tab - inefficient queries
+ *  @see https://sourceforge.net/tracker/?func=detail&aid=2900767&group_id=176962&atid=879332
  */
 public class GridTab implements DataStatusListener, Evaluatee, Serializable
 {
@@ -741,7 +743,7 @@ public class GridTab implements DataStatusListener, Evaluatee, Serializable
 			return query.getWhereClause();
 		}
 
-		//	Find Refernce Column e.g. BillTo_ID -> C_BPartner_Location_ID
+		//	Find Reference Column e.g. BillTo_ID -> C_BPartner_Location_ID
 		String sql = "SELECT cc.ColumnName "
 			+ "FROM AD_Column c"
 			+ " INNER JOIN AD_Ref_Table r ON (c.AD_Reference_Value_ID=r.AD_Reference_ID)"
@@ -823,11 +825,13 @@ public class GridTab implements DataStatusListener, Evaluatee, Serializable
 		}
 
 		query.setTableName("xx");
-		StringBuffer result = new StringBuffer ("EXISTS (SELECT * FROM ")
+		// use IN instead of EXISTS as subquery should be highly selective
+		StringBuffer result = new StringBuffer (getTableName()).append(".").append(tabKeyColumn)
+			.append(" IN (SELECT xx.").append(tabKeyColumn)
+			.append(" FROM ")
 			.append(tableName).append(" xx WHERE ")
 			.append(query.getWhereClause(true))
-			.append(" AND xx.").append(tabKeyColumn).append("=")
-			.append(getTableName()).append(".").append(tabKeyColumn).append(")");
+			.append(")");
 		log.fine(result.toString());
 		return result.toString();
 	}	//	validateQuery
diff --git a/base/src/org/compiere/util/DB.java b/base/src/org/compiere/util/DB.java
index 15ef016092..491819fa79 100644
--- a/base/src/org/compiere/util/DB.java
+++ b/base/src/org/compiere/util/DB.java
@@ -85,6 +85,8 @@ import org.compiere.process.SequenceCheck;
  * 			https://sourceforge.net/tracker/?func=detail&aid=2873324&group_id=176962&atid=879332
  * 		<li>FR [ 2873891 ] DB.getKeyNamePairs should use trxName
  * 			https://sourceforge.net/tracker/?func=detail&aid=2873891&group_id=176962&atid=879335
+ *  @author Paul Bowden, phib BF 2900767 Zoom to child tab - inefficient queries
+ *  @see https://sourceforge.net/tracker/?func=detail&aid=2900767&group_id=176962&atid=879332
  */
 public final class DB
 {
@@ -1676,10 +1678,10 @@ public final class DB
             if (TableName.endsWith("Line"))
             {
                 String hdr = TableName.substring(0, TableName.indexOf("Line"));
+                // use IN instead of EXISTS as the subquery should be highly selective
                 sql = "SELECT IsSOTrx FROM " + hdr
-                    + " h WHERE EXISTS (SELECT * FROM " + TableName
-                    + " l WHERE h." + hdr + "_ID=l." + hdr + "_ID AND "
-                    + whereClause + ")";
+                    + " h WHERE h." + hdr + "_ID IN (SELECT l." + hdr + "_ID FROM " + TableName
+                    + " l WHERE " + whereClause + ")";
                 PreparedStatement pstmt2 = null;
                 ResultSet rs2 = null;
                 try