[teiid-commits] teiid SVN: r4175 - in branches/7.7.x: connectors/translator-jdbc/src/main/java/org/teiid/translator/jdbc/oracle and 1 other directories.

[teiid-commits at lists.jboss.org]

Author: jolee
Date: 2012-06-12 10:05:05 -0400 (Tue, 12 Jun 2012)
New Revision: 4175

Modified:
   branches/7.7.x/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java
   branches/7.7.x/connectors/translator-jdbc/src/main/java/org/teiid/translator/jdbc/oracle/OracleExecutionFactory.java
   branches/7.7.x/connectors/translator-jdbc/src/test/java/org/teiid/translator/jdbc/oracle/TestOracleTranslator.java
Log:
TEIID-2069 Optimze add LIMIT clause to SELECT within a Virtual Procedure using Oracle

Modified: branches/7.7.x/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java
===================================================================
--- branches/7.7.x/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java	2012-06-11 21:04:27 UTC (rev 4174)
+++ branches/7.7.x/api/src/main/java/org/teiid/language/visitor/SQLStringVisitor.java	2012-06-12 14:05:05 UTC (rev 4175)
@@ -105,7 +105,11 @@
      * @return the name of that element or group as defined in the source
      */
     protected String getName(AbstractMetadataRecord object) {
-        String nameInSource = object.getNameInSource();
+        return getRecordName(object);
+    }
+
+	public static String getRecordName(AbstractMetadataRecord object) {
+		String nameInSource = object.getNameInSource();
         if(nameInSource != null && nameInSource.length() > 0) {
             return nameInSource;
         }

Modified: branches/7.7.x/connectors/translator-jdbc/src/main/java/org/teiid/translator/jdbc/oracle/OracleExecutionFactory.java
===================================================================
--- branches/7.7.x/connectors/translator-jdbc/src/main/java/org/teiid/translator/jdbc/oracle/OracleExecutionFactory.java	2012-06-11 21:04:27 UTC (rev 4174)
+++ branches/7.7.x/connectors/translator-jdbc/src/main/java/org/teiid/translator/jdbc/oracle/OracleExecutionFactory.java	2012-06-12 14:05:05 UTC (rev 4175)
@@ -36,9 +36,11 @@
 import java.util.List;
 
 import org.teiid.language.*;
+import org.teiid.language.Comparison.Operator;
 import org.teiid.language.SQLConstants.Tokens;
 import org.teiid.language.SetQuery.Operation;
 import org.teiid.language.visitor.CollectorVisitor;
+import org.teiid.language.visitor.SQLStringVisitor;
 import org.teiid.logging.LogConstants;
 import org.teiid.logging.LogManager;
 import org.teiid.metadata.AbstractMetadataRecord;
@@ -285,6 +287,21 @@
     	}
 		Limit limit = queryCommand.getLimit();
 		queryCommand.setLimit(null);
+		
+		if (command instanceof Select) {
+			Select select = (Select)command;
+			
+			TableReference tr = select.getFrom().get(0);
+			if (tr instanceof NamedTable && isDual((NamedTable)tr)) {
+				if (limit.getRowOffset() > 0 || limit.getRowLimit() == 0) {
+					//no data
+					select.setWhere(new Comparison(new Literal(1, TypeFacility.RUNTIME_TYPES.INTEGER), new Literal(0, TypeFacility.RUNTIME_TYPES.INTEGER), Operator.EQ));
+					return null;
+				}
+				return null; //dual does not allow a limit
+			}
+		}
+		
     	List<Object> parts = new ArrayList<Object>();
     	parts.add("SELECT "); //$NON-NLS-1$
     	/*
@@ -327,7 +344,18 @@
 		}
 		return parts;
     }
-
+    
+	private boolean isDual(NamedTable table) {
+		String groupName = null;
+		AbstractMetadataRecord groupID = table.getMetadataObject();
+		if(groupID != null) {              
+		    groupName = SQLStringVisitor.getRecordName(groupID);
+		} else {
+		    groupName = table.getName();
+		}
+		return DUAL.equalsIgnoreCase(groupName);
+	}
+
     @Override
     public boolean useAsInGroupAlias(){
         return false;
@@ -506,14 +534,7 @@
 
 			private void stripDualAlias(NamedTable table) {
 				if (table.getCorrelationName() != null) {
-    				String groupName = null;
-    				AbstractMetadataRecord groupID = table.getMetadataObject();
-                    if(groupID != null) {              
-                        groupName = getName(groupID);
-                    } else {
-                        groupName = table.getName();
-                    }
-                    if (DUAL.equalsIgnoreCase(groupName)) {
+                    if (isDual(table)) {
                     	table.setCorrelationName(null);
                     }
     			}

Modified: branches/7.7.x/connectors/translator-jdbc/src/test/java/org/teiid/translator/jdbc/oracle/TestOracleTranslator.java
===================================================================
--- branches/7.7.x/connectors/translator-jdbc/src/test/java/org/teiid/translator/jdbc/oracle/TestOracleTranslator.java	2012-06-11 21:04:27 UTC (rev 4174)
+++ branches/7.7.x/connectors/translator-jdbc/src/test/java/org/teiid/translator/jdbc/oracle/TestOracleTranslator.java	2012-06-12 14:05:05 UTC (rev 4175)
@@ -664,6 +664,28 @@
             null,
             output);
     }
+    
+    @Test public void testDUALLimit() throws Exception {
+        String input = "SELECT something FROM DUAL as g0 LIMIT 2"; //$NON-NLS-1$
+        String output = "SELECT seq.nextval FROM DUAL"; //$NON-NLS-1$
+               
+        helpTestVisitor(getOracleSpecificMetadata(),
+            input, 
+            EMPTY_CONTEXT,
+            null,
+            output);
+    }
+    
+    @Test public void testDUALLimit1() throws Exception {
+        String input = "SELECT something FROM DUAL as g0 LIMIT 1, 2"; //$NON-NLS-1$
+        String output = "SELECT seq.nextval FROM DUAL WHERE 1 = 0"; //$NON-NLS-1$
+               
+        helpTestVisitor(getOracleSpecificMetadata(),
+            input, 
+            EMPTY_CONTEXT,
+            null,
+            output);
+    }
 
     /**
      * Test Oracle's rownum pseudo-column.  Not a real column, so it can't