Merge pull request #902 from katzyn/nested_joins

Remove DbSettings.nestedJoins

h2/src/main/org/h2/command/Parser.java

@@ -1368,14 +1368,9 @@ public class Parser {
                         query, currentSelect);
             } else {
                 TableFilter top;
-                if (database.getSettings().nestedJoins) {
-                    top = readTableFilter(false);
-                    top = readJoin(top, currentSelect, false, false);
-                    top = getNested(top);
-                } else {
-                    top = readTableFilter(fromOuter);
-                    top = readJoin(top, currentSelect, false, fromOuter);
-                }
+                top = readTableFilter(false);
+                top = readJoin(top, currentSelect, false, false);
+                top = getNested(top);
                 read(")");
                 alias = readFromAlias(null);
                 if (alias != null) {
@@ -1726,88 +1721,57 @@ public class Parser {
             boolean nested, boolean fromOuter) {
         boolean joined = false;
         TableFilter last = top;
-        boolean nestedJoins = database.getSettings().nestedJoins;
         while (true) {
+            TableFilter join;
             if (readIf("RIGHT")) {
                 readIf("OUTER");
                 read("JOIN");
-                joined = true;
                 // the right hand side is the 'inner' table usually
-                TableFilter newTop = readTableFilter(fromOuter);
-                newTop = readJoin(newTop, command, nested, true);
+                join = readTableFilter(fromOuter);
+                join = readJoin(join, command, nested, true);
                 Expression on = null;
                 if (readIf("ON")) {
                     on = readExpression();
                 }
-                if (nestedJoins) {
-                    top = getNested(top);
-                    newTop.addJoin(top, true, false, on);
-                } else {
-                    newTop.addJoin(top, true, false, on);
-                }
-                top = newTop;
-                last = newTop;
+                top = getNested(top);
+                join.addJoin(top, true, false, on);
+                top = join;
             } else if (readIf("LEFT")) {
                 readIf("OUTER");
                 read("JOIN");
-                joined = true;
-                TableFilter join = readTableFilter(true);
-                if (nestedJoins) {
-                    join = readJoin(join, command, true, true);
-                } else {
-                    top = readJoin(top, command, false, true);
-                }
+                join = readTableFilter(true);
+                join = readJoin(join, command, true, true);
                 Expression on = null;
                 if (readIf("ON")) {
                     on = readExpression();
                 }
                 top.addJoin(join, true, false, on);
-                last = join;
             } else if (readIf("FULL")) {
                 throw getSyntaxError();
             } else if (readIf("INNER")) {
                 read("JOIN");
-                joined = true;
-                TableFilter join = readTableFilter(fromOuter);
+                join = readTableFilter(fromOuter);
                 top = readJoin(top, command, false, false);
                 Expression on = null;
                 if (readIf("ON")) {
                     on = readExpression();
                 }
-                if (nestedJoins) {
-                    top.addJoin(join, false, false, on);
-                } else {
-                    top.addJoin(join, fromOuter, false, on);
-                }
-                last = join;
+                top.addJoin(join, false, false, on);
             } else if (readIf("JOIN")) {
-                joined = true;
-                TableFilter join = readTableFilter(fromOuter);
+                join = readTableFilter(fromOuter);
                 top = readJoin(top, command, false, false);
                 Expression on = null;
                 if (readIf("ON")) {
                     on = readExpression();
                 }
-                if (nestedJoins) {
-                    top.addJoin(join, false, false, on);
-                } else {
-                    top.addJoin(join, fromOuter, false, on);
-                }
-                last = join;
+                top.addJoin(join, false, false, on);
             } else if (readIf("CROSS")) {
                 read("JOIN");
-                joined = true;
-                TableFilter join = readTableFilter(fromOuter);
-                if (nestedJoins) {
-                    top.addJoin(join, false, false, null);
-                } else {
-                    top.addJoin(join, fromOuter, false, null);
-                }
-                last = join;
+                join = readTableFilter(fromOuter);
+                top.addJoin(join, false, false, null);
             } else if (readIf("NATURAL")) {
                 read("JOIN");
-                joined = true;
-                TableFilter join = readTableFilter(fromOuter);
+                join = readTableFilter(fromOuter);
                 Column[] tableCols = last.getTable().getColumns();
                 Column[] joinCols = join.getTable().getColumns();
                 String tableSchema = last.getTable().getSchema().getName();
@@ -1836,15 +1800,12 @@ public class Parser {
                         }
                     }
                 }
-                if (nestedJoins) {
-                    top.addJoin(join, false, nested, on);
-                } else {
-                    top.addJoin(join, fromOuter, false, on);
-                }
-                last = join;
+                top.addJoin(join, false, nested, on);
             } else {
                 break;
             }
+            joined = true;
+            last = join;
         }
         if (nested && joined) {
             top = getNested(top);

h2/src/main/org/h2/command/dml/Select.java

@@ -1046,26 +1046,10 @@ public class Select extends Query {
             Expression on = f.getJoinCondition();
             if (on != null) {
                 if (!on.isEverything(ExpressionVisitor.EVALUATABLE_VISITOR)) {
-                    if (session.getDatabase().getSettings().nestedJoins) {
-                        // need to check that all added are bound to a table
-                        on = on.optimize(session);
-                        if (!f.isJoinOuter() && !f.isJoinOuterIndirect()) {
-                            f.removeJoinCondition();
-                            addCondition(on);
-                        }
-                    } else {
-                        if (f.isJoinOuter()) {
-                            // this will check if all columns exist - it may or
-                            // may not throw an exception
-                            on = on.optimize(session);
-                            // it is not supported even if the columns exist
-                            throw DbException.get(
-                                    ErrorCode.UNSUPPORTED_OUTER_JOIN_CONDITION_1,
-                                    on.getSQL());
-                        }
+                    // need to check that all added are bound to a table
+                    on = on.optimize(session);
+                    if (!f.isJoinOuter() && !f.isJoinOuterIndirect()) {
                         f.removeJoinCondition();
-                        // need to check that all added are bound to a table
-                        on = on.optimize(session);
                         addCondition(on);
                     }
                 }

h2/src/main/org/h2/engine/DbSettings.java

@@ -7,6 +7,9 @@ package org.h2.engine;
 
 import java.util.HashMap;
 
+import org.h2.message.DbException;
+import org.h2.util.Utils;
+
 /**
  * This class contains various database-level settings. To override the
  * documented default value for a database, append the setting in the database
@@ -164,12 +167,6 @@ public class DbSettings extends SettingsBase {
      */
     public final int maxQueryTimeout = get("MAX_QUERY_TIMEOUT", 0);
 
-    /**
-     * Database setting <code>NESTED_JOINS</code> (default: true).<br />
-     * Whether nested joins should be supported.
-     */
-    public final boolean nestedJoins = get("NESTED_JOINS", true);
-
     /**
      * Database setting <code>OPTIMIZE_DISTINCT</code> (default: true).<br />
      * Improve the performance of simple DISTINCT queries if an index is
@@ -363,6 +360,9 @@ public class DbSettings extends SettingsBase {
 
     private DbSettings(HashMap<String, String> s) {
         super(s);
+        if (s.get("NESTED_JOINS") != null || Utils.getProperty("h2.nestedJoins", null) != null) {
+            throw DbException.getUnsupportedException("NESTED_JOINS setting is not available since 1.4.197");
+        }
     }
 
     /**

h2/src/main/org/h2/expression/ExpressionColumn.java

@@ -37,7 +37,6 @@ public class ExpressionColumn extends Expression {
     private ColumnResolver columnResolver;
     private int queryLevel;
     private Column column;
-    private boolean evaluatable;
 
     public ExpressionColumn(Database database, Column column) {
         this.database = database;
@@ -205,9 +204,6 @@ public class ExpressionColumn extends Expression {
 
     @Override
     public void setEvaluatable(TableFilter tableFilter, boolean b) {
-        if (columnResolver != null && tableFilter == columnResolver.getTableFilter()) {
-            evaluatable = b;
-        }
     }
 
     public Column getColumn() {
@@ -287,19 +283,15 @@ public class ExpressionColumn extends Expression {
         case ExpressionVisitor.INDEPENDENT:
             return this.queryLevel < visitor.getQueryLevel();
         case ExpressionVisitor.EVALUATABLE:
-            // if the current value is known (evaluatable set)
-            // or if this columns belongs to a 'higher level' query and is
+            // if this column belongs to a 'higher level' query and is
             // therefore just a parameter
-            if (database.getSettings().nestedJoins) {
-                if (visitor.getQueryLevel() < this.queryLevel) {
-                    return true;
-                }
-                if (getTableFilter() == null) {
-                    return false;
-                }
-                return getTableFilter().isEvaluatable();
+            if (visitor.getQueryLevel() < this.queryLevel) {
+                return true;
+            }
+            if (getTableFilter() == null) {
+                return false;
             }
-            return evaluatable || visitor.getQueryLevel() < this.queryLevel;
+            return getTableFilter().isEvaluatable();
         case ExpressionVisitor.SET_MAX_DATA_MODIFICATION_ID:
             visitor.addDataModificationId(column.getTable().getMaxDataModificationId());
             return true;

h2/src/main/org/h2/table/TableFilter.java

@@ -230,14 +230,14 @@ public class TableFilter implements ColumnResolver {
         }
 
         if (nestedJoin != null) {
-            setEvaluatable(nestedJoin);
+            setEvaluatable(true);
             item.setNestedJoinPlan(nestedJoin.getBestPlanItem(s, filters, filter, allColumnsSet));
             // TODO optimizer: calculate cost of a join: should use separate
             // expected row number and lookup cost
             item.cost += item.cost * item.getNestedJoinPlan().cost;
         }
         if (join != null) {
-            setEvaluatable(join);
+            setEvaluatable(true);
             do {
                 filter++;
             } while (filters[filter] != join);
@@ -249,25 +249,6 @@ public class TableFilter implements ColumnResolver {
         return item;
     }
 
-    private void setEvaluatable(TableFilter join) {
-        if (session.getDatabase().getSettings().nestedJoins) {
-            setEvaluatable(true);
-            return;
-        }
-        // this table filter is now evaluatable - in all sub-joins
-        do {
-            Expression e = join.getJoinCondition();
-            if (e != null) {
-                e.setEvaluatable(this, true);
-            }
-            TableFilter n = join.getNestedJoin();
-            if (n != null) {
-                setEvaluatable(n);
-            }
-            join = join.getJoin();
-        } while (join != null);
-    }
-
     /**
      * Set what plan item (index, cost, masks) to use.
      *
@@ -663,13 +644,11 @@ public class TableFilter implements ColumnResolver {
             final Expression on) {
         if (on != null) {
             on.mapColumns(this, 0);
-            if (session.getDatabase().getSettings().nestedJoins) {
-                TableFilterVisitor visitor = new MapColumnsVisitor(on);
-                visit(visitor);
-                filter.visit(visitor);
-            }
+            TableFilterVisitor visitor = new MapColumnsVisitor(on);
+            visit(visitor);
+            filter.visit(visitor);
         }
-        if (nested && session.getDatabase().getSettings().nestedJoins) {
+        if (nested) {
             if (nestedJoin != null) {
                 throw DbException.throwInternalError();
             }
@@ -685,20 +664,8 @@ public class TableFilter implements ColumnResolver {
             if (join == null) {
                 join = filter;
                 filter.joinOuter = outer;
-                if (session.getDatabase().getSettings().nestedJoins) {
-                    if (outer) {
-                        filter.visit(new JOIVisitor());
-                    }
-                } else {
-                    if (outer) {
-                        // convert all inner joins on the right hand side to
-                        // outer joins
-                        TableFilter f = filter.join;
-                        while (f != null) {
-                            f.joinOuter = true;
-                            f = f.join;
-                        }
-                    }
+                if (outer) {
+                    filter.visit(new JOIVisitor());
                 }
                 if (on != null) {
                     filter.mapAndAddFilter(on);