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From banda...@apache.org
Subject svn commit: r326969 - in /db/derby/code/branches/10.1/java: engine/org/apache/derby/impl/sql/ engine/org/apache/derby/impl/sql/compile/ testing/org/apache/derbyTesting/functionTests/master/ testing/org/apache/derbyTesting/functionTests/tests/lang/
Date Thu, 20 Oct 2005 18:39:11 GMT
Author: bandaram
Date: Thu Oct 20 11:38:48 2005
New Revision: 326969

URL: http://svn.apache.org/viewcvs?rev=326969&view=rev
Log:
DERBY-424: Ported from TRUNK. 

Basically, the problem is that, during the compile phase of views,
the reference to the view gets replaced by the view definition, which causes
us to loose the information that the view might have belonged in SESSION schema.
In order to fix this, during the bind phase in FromList, before the view gets
replaced by its definition, I find out if the view is from SESSION schema, If
yes, then I save this information in FromList and this gets used by FromList
when it is asked if it has any items referencing SESSION schema objects. This
information is again lost during the optimization and generate phase and hence
I moved the check for SESSION schema reference to right after the bind phase in
GenericStatement. If there is a reference to SESSION schema object,
GenericStatement will remove the statement from the cache.

Submitted by Mamta Satoor (msatoor@gmail.com)


Modified:
    db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericPreparedStatement.java
    db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericStatement.java
    db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/compile/FromList.java
    db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/master/declareGlobalTempTableJava.out
    db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/tests/lang/declareGlobalTempTableJava.java

Modified: db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericPreparedStatement.java
URL: http://svn.apache.org/viewcvs/db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericPreparedStatement.java?rev=326969&r1=326968&r2=326969&view=diff
==============================================================================
--- db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericPreparedStatement.java
(original)
+++ db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericPreparedStatement.java
Thu Oct 20 11:38:48 2005
@@ -880,7 +880,15 @@
 	}
 
 	/**
-	 * Return true if the query node for this statement references SESSION schema tables.
+	 * Return true if the query node for this statement references SESSION schema
+	 * tables/views.
+	 * This method gets called at the very beginning of the compile phase of any statement.
+	 * If the statement which needs to be compiled is already found in cache, then there is
+	 * no need to compile it again except the case when the statement is referencing SESSION
+	 * schema objects. There is a small window where such a statement might get cached 
+	 * temporarily (a statement referencing SESSION schema object will be removed from the
+	 * cache after the bind phase is over because that is when we know for sure that the 
+	 * statement is referencing SESSION schema objects.)
 	 *
 	 * @return	true if references SESSION schema tables, else false
 	 */
@@ -888,6 +896,30 @@
 	{
 		return referencesSessionSchema;
 	}
+	
+	/**
+	 * Return true if the QueryTreeNode references SESSION schema tables/views.
+	 * The return value is also saved in the local field because it will be 
+	 * used by referencesSessionSchema() method. 
+	 * This method gets called when the statement is not found in cache and 
+	 * hence it is getting compiled.
+	 * At the beginning of compilation for any statement, first we check if
+	 * the statement's plan already exist in the cache. If not, then we add
+	 * the statement to the cache and continue with the parsing and binding.
+	 * At the end of the binding, this method gets called to see if the 
+	 * QueryTreeNode references a SESSION schema object. If it does, then
+	 * we want to remove it from the cache, since any statements referencing
+	 * SESSION schema objects should never get cached.  
+	 *
+	 * @return	true if references SESSION schema tables/views, else false
+	 */
+	public boolean referencesSessionSchema(QueryTreeNode qt)
+	throws StandardException {
+		//If the query references a SESSION schema table (temporary or permanent), then
+		// mark so in this statement
+		referencesSessionSchema = qt.referencesSessionSchema();
+		return(referencesSessionSchema);
+	}
 
 	//
 	// class interface
@@ -902,23 +934,15 @@
 		@param dtd	The DataTypeDescriptors for the parameters, if any
 		@param ac the generated class for this statement
 
-		@return	true if there is a reference to SESSION schema tables, else false
-
 		@exception StandardException thrown on failure.
 	 */
-	boolean completeCompile(QueryTreeNode qt)
+	void completeCompile(QueryTreeNode qt)
 						throws StandardException {
 		//if (finished)
 		//	throw StandardException.newException(SQLState.LANG_STATEMENT_CLOSED, "completeCompile()");
 
 		paramTypeDescriptors = qt.getParameterTypes();
 
-		//If the query references a SESSION schema table (temporary or permanent), then mark so
in this statement
-		//This information will be used by EXECUTE STATEMENT if it is executing a statement that
was created with NOCOMPILE. Because
-		//of NOCOMPILE, we could not catch SESSION schema table reference by the statement at CREATE
STATEMENT time. Need to catch
-		//such statements at EXECUTE STATEMENT time when the query is getting compiled.
-		referencesSessionSchema = qt.referencesSessionSchema();
-
 		// erase cursor info in case statement text changed
 		if (targetTable!=null) {
 			targetTable = null;
@@ -952,8 +976,7 @@
 		}
 		isValid = true;
 
-		//if this statement is referencing session schema tables, then we do not want cache it.

-		return referencesSessionSchema;
+		return;
 	}
 
 	public GeneratedClass getActivationClass()

Modified: db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericStatement.java
URL: http://svn.apache.org/viewcvs/db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericStatement.java?rev=326969&r1=326968&r2=326969&view=diff
==============================================================================
--- db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericStatement.java
(original)
+++ db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/GenericStatement.java
Thu Oct 20 11:38:48 2005
@@ -344,6 +344,42 @@
 						}
 					}
 
+					//Derby424 - In order to avoid caching select statements referencing
+					// any SESSION schema objects (including statements referencing views
+					// in SESSION schema), we need to do the SESSION schema object check
+					// here.  
+					//a specific eg for statement referencing a view in SESSION schema 
+					//CREATE TABLE t28A (c28 int)
+					//INSERT INTO t28A VALUES (280),(281)
+					//CREATE VIEW SESSION.t28v1 as select * from t28A
+					//SELECT * from SESSION.t28v1 should show contents of view and we
+					// should not cache this statement because a user can later define
+					// a global temporary table with the same name as the view name.
+					//Following demonstrates that
+					//DECLARE GLOBAL TEMPORARY TABLE SESSION.t28v1(c21 int, c22 int) not
+					//     logged
+					//INSERT INTO SESSION.t28v1 VALUES (280,1),(281,2)
+					//SELECT * from SESSION.t28v1 should show contents of global temporary
+					//table and not the view.  Since this select statement was not cached
+					// earlier, it will be compiled again and will go to global temporary
+					// table to fetch data. This plan will not be cached either because
+					// select statement is using SESSION schema object.
+					//
+					//Following if statement makes sure that if the statement is
+					// referencing SESSION schema objects, then we do not want to cache it.
+					// We will remove the entry that was made into the cache for 
+					//this statement at the beginning of the compile phase.
+					//The reason we do this check here rather than later in the compile
+					// phase is because for a view, later on, we loose the information that
+					// it was referencing SESSION schema because the reference
+					//view gets replaced with the actual view definition. Right after
+					// binding, we still have the information on the view and that is why
+					// we do the check here.
+					if (preparedStmt.referencesSessionSchema(qt)) {
+						if (foundInCache)
+							((GenericLanguageConnectionContext)lcc).removeStatement(this);
+					}
+					
 					qt = qt.optimize();
 
 					optimizeTime = getCurrentTimeMillis(lcc);
@@ -468,14 +504,7 @@
 												qt.executeSchemaName()
 												);
 					preparedStmt.setSPSName(qt.getSPSName());
-
-					//if this statement is referencing session schema tables, then we do not want cache
it. Following will remove the
-					//entry that was made into the cache for this statement at the beginning of the compile
phase
-					if (preparedStmt.completeCompile(qt)) {
-						if (foundInCache)
-							((GenericLanguageConnectionContext)lcc).removeStatement(this);
-					}
-
+					preparedStmt.completeCompile(qt);
 					preparedStmt.setCompileTimeWarnings(cc.getWarnings());
 				}
 				catch (StandardException e) 	// hold it, throw it

Modified: db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/compile/FromList.java
URL: http://svn.apache.org/viewcvs/db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/compile/FromList.java?rev=326969&r1=326968&r2=326969&view=diff
==============================================================================
--- db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/compile/FromList.java
(original)
+++ db/derby/code/branches/10.1/java/engine/org/apache/derby/impl/sql/compile/FromList.java
Thu Oct 20 11:38:48 2005
@@ -61,6 +61,12 @@
 	// true by default.
 	boolean 	useStatistics = true;
 
+	// FromList could have a view in it's list. If the view is defined in SESSION
+	// schema, then we do not want to cache the statement's plan. This boolean
+	// will help keep track of such a condition.
+	private boolean  referencesSessionSchema;
+
+
 	/** Initializer for a FromList */
 
 	public void init(Object optimizeJoinOrder)
@@ -208,6 +214,14 @@
 		FromTable		fromTable;
 		boolean			found = false;
 
+		// Following if will return true if this FromList object had any VIEWs
+		// from SESSION schema as elements.  This information is gathered during
+		// the bindTables method. At the end of the bindTables, we loose
+		// the information on VIEWs since they get replaced with their view
+		// definition. Hence, we need to intercept in the middle on the bindTables
+		// method and save that information in referencesSeesionSchema field.
+		if (referencesSessionSchema) return true;
+
 		/* Check for table or VTI name in FROM list */
 		int size = size();
 		for (int index = 0; index < size; index++)
@@ -290,12 +304,22 @@
 		for (int index = 0; index < size; index++)
 		{
 			fromTable = (FromTable) elementAt(index);
-			setElementAt(fromTable.bindNonVTITables(dataDictionary, fromListParam), index);
+			ResultSetNode newNode = fromTable.bindNonVTITables(dataDictionary, fromListParam);
+			// If the fromTable is a view in the SESSION schema, then we need to save that information
+			// in referencesSessionSchema element. The reason for this is that the view will get
+			// replaced by it's view definition and we will loose the information that the statement
+			// was referencing a SESSION schema object. 
+			if (fromTable.referencesSessionSchema())
+				referencesSessionSchema = true;
+			setElementAt(newNode, index);
 		}
 		for (int index = 0; index < size; index++)
 		{
 			fromTable = (FromTable) elementAt(index);
-			setElementAt(fromTable.bindVTITables(fromListParam), index);
+			ResultSetNode newNode = fromTable.bindVTITables(fromListParam);
+			if (fromTable.referencesSessionSchema())
+				referencesSessionSchema = true;
+			setElementAt(newNode, index);
 		}
 	}
 

Modified: db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/master/declareGlobalTempTableJava.out
URL: http://svn.apache.org/viewcvs/db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/master/declareGlobalTempTableJava.out?rev=326969&r1=326968&r2=326969&view=diff
==============================================================================
--- db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/master/declareGlobalTempTableJava.out
(original)
+++ db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/master/declareGlobalTempTableJava.out
Thu Oct 20 11:38:48 2005
@@ -142,6 +142,24 @@
 TEST27A : CREATE VIEW not allowed on physical table in SESSION schema
 Expected message: The requested function can not reference tables in SESSION schema.
 TEST27A PASSED
+TEST28A : CREATE VIEW in SESSION schema referencing a table outside of SESSION schema
+SELECT * from SESSION.t28v1 should show contents of view
+	 C28
+	 ---
+	{280}
+	{281}
+Now declare a global temporary table with same name as the view in SESSION schema
+SELECT * from SESSION.t28v1 should show contents of global temporary table
+	 C21,C22
+	 --- ---
+	{280,1}
+	{281,2}
+We have dropped global temporary table hence SESSION.t28v1 should point to view at this point
+	 C28
+	 ---
+	{280}
+	{281}
+TEST28A PASSED
 TEST29A : DELETE FROM global temporary table allowed.
 	 1
 	 -

Modified: db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/tests/lang/declareGlobalTempTableJava.java
URL: http://svn.apache.org/viewcvs/db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/tests/lang/declareGlobalTempTableJava.java?rev=326969&r1=326968&r2=326969&view=diff
==============================================================================
--- db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/tests/lang/declareGlobalTempTableJava.java
(original)
+++ db/derby/code/branches/10.1/java/testing/org/apache/derbyTesting/functionTests/tests/lang/declareGlobalTempTableJava.java
Thu Oct 20 11:38:48 2005
@@ -984,6 +984,27 @@
 			System.out.println("TEST27A PASSED");
 		}
 
+		//Derby424 - Queryplan for a query using SESSION schema view is incorrectly put in statement
cache. This 
+		//could cause incorrect plan getting executed later if a temp. table is created with that
name.
+		System.out.println("TEST28A : CREATE VIEW in SESSION schema referencing a table outside
of SESSION schema");
+		s.executeUpdate("CREATE TABLE t28A (c28 int)");
+		s.executeUpdate("INSERT INTO t28A VALUES (280),(281)");
+		s.executeUpdate("CREATE VIEW SESSION.t28v1 as select * from t28A");
+		System.out.println("SELECT * from SESSION.t28v1 should show contents of view");
+		dumpRS(s.executeQuery("SELECT * from SESSION.t28v1"));
+		System.out.println("Now declare a global temporary table with same name as the view in
SESSION schema");
+		s.executeUpdate("DECLARE GLOBAL TEMPORARY TABLE SESSION.t28v1(c21 int, c22 int) not logged");
+		s.executeUpdate("INSERT INTO SESSION.t28v1 VALUES (280,1),(281,2)");
+		System.out.println("SELECT * from SESSION.t28v1 should show contents of global temporary
table");
+		dumpRS(s.executeQuery("SELECT * from SESSION.t28v1"));
+		s.executeUpdate("DROP TABLE SESSION.t28v1");
+		System.out.println("We have dropped global temporary table hence SESSION.t28v1 should point
to view at this point");
+		dumpRS(s.executeQuery("SELECT * from SESSION.t28v1"));
+		s.executeUpdate("DROP VIEW SESSION.t28v1");
+		con1.rollback();
+		con1.commit();
+		System.out.println("TEST28A PASSED");
+
 		try
 		{
 			System.out.println("TEST29A : DELETE FROM global temporary table allowed.");



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