Improved EXPLAIN plan formatting and documentation.

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

@@ -188,9 +188,12 @@ public class Insert extends Prepared implements ResultTarget {
         if (list.size() > 0) {
             buff.append("VALUES ");
             int row = 0;
+            if (list.size() > 1) {
+                buff.append("\n");
+            }
             for (Expression[] expr : list) {
                 if (row++ > 0) {
-                    buff.append(", ");
+                    buff.append(",\n");
                 }
                 buff.append('(');
                 buff.resetCount();

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

@@ -140,14 +140,14 @@ public class Update extends Prepared {
 
     public String getPlanSQL() {
         StatementBuilder buff = new StatementBuilder("UPDATE ");
-        buff.append(tableFilter.getPlanSQL(false)).append("\nSET ");
+        buff.append(tableFilter.getPlanSQL(false)).append("\nSET\n    ");
         Table table = tableFilter.getTable();
         int columnCount = table.getColumns().length;
         for (int i = 0; i < columnCount; i++) {
             Expression newExpr = expressions[i];
             if (newExpr != null) {
                 Column column = table.getColumn(i);
-                buff.appendExceptFirst(",\n");
+                buff.appendExceptFirst(",\n    ");
                 buff.append(column.getName()).append(" = ").append(newExpr.getSQL());
             }
         }

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

@@ -46,10 +46,10 @@ public class ConditionAndOr extends Condition {
         String sql;
         switch (andOrType) {
         case AND:
-            sql = left.getSQL() + " AND " + right.getSQL();
+            sql = left.getSQL() + "\n    AND " + right.getSQL();
             break;
         case OR:
-            sql = left.getSQL() + " OR " + right.getSQL();
+            sql = left.getSQL() + "\n    OR " + right.getSQL();
             break;
         default:
             throw DbException.throwInternalError("andOrType=" + andOrType);

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

@@ -15,6 +15,7 @@ import org.h2.message.DbException;
 import org.h2.result.ResultInterface;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
+import org.h2.util.StringUtils;
 import org.h2.value.Value;
 import org.h2.value.ValueBoolean;
 import org.h2.value.ValueNull;
@@ -101,7 +102,7 @@ public class ConditionInSelect extends Condition {
     }
 
     public String getSQL() {
-        return "(" + left.getSQL() + " IN(" + query.getPlanSQL() + "))";
+        return "(" + left.getSQL() + " IN(\n" + StringUtils.indent(query.getPlanSQL(), 4, false) + "))";
     }
 
     public void updateAggregate(Session session) {

h2/src/main/org/h2/index/FunctionIndex.java

@@ -91,4 +91,8 @@ public class FunctionIndex extends BaseIndex {
         return functionTable.getRowCountApproximation();
     }
 
+    public String getPlanSQL() {
+        return "function";
+    }
+
 }

h2/src/main/org/h2/index/MetaIndex.java

@@ -97,4 +97,8 @@ public class MetaIndex extends BaseIndex {
         return MetaTable.ROW_COUNT_APPROXIMATION;
     }
 
+    public String getPlanSQL() {
+        return "meta";
+    }
+
 }

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

@@ -616,13 +616,16 @@ public class TableFilter implements ColumnResolver {
             }
         }
         if (nestedJoin != null) {
-            buff.append("(\n");
+            StringBuffer buffNested = new StringBuffer();
             TableFilter n = nestedJoin;
             do {
-                buff.append(n.getPlanSQL(n != nestedJoin));
-                buff.append("\n");
+                buffNested.append(n.getPlanSQL(n != nestedJoin));
+                buffNested.append("\n");
                 n = (TableFilter) n.getJoin();
             } while (n != null);
+
+            buff.append("(\n");
+            buff.append(StringUtils.indent(buffNested.toString(), 4, false));
             buff.append(") ON ");
             if (joinCondition == null) {
                 // need to have a ON expression,
@@ -638,21 +641,24 @@ public class TableFilter implements ColumnResolver {
             buff.append(' ').append(Parser.quoteIdentifier(alias));
         }
         if (index != null) {
-            buff.append(" /* ");
+            buff.append("\n");
             StatementBuilder planBuff = new StatementBuilder();
             planBuff.append(index.getPlanSQL());
             if (indexConditions.size() > 0) {
                 planBuff.append(": ");
                 for (IndexCondition condition : indexConditions) {
-                    planBuff.appendExceptFirst(" AND ");
+                    planBuff.appendExceptFirst("\n    AND ");
                     planBuff.append(condition.getSQL());
                 }
             }
             String plan = StringUtils.quoteRemarkSQL(planBuff.toString());
-            buff.append(plan).append(" */");
+            if (plan.indexOf('\n') >= 0) {
+                plan += "\n";
+            }
+            buff.append(StringUtils.indent("/* " + plan + " */", 4, false));
         }
         if (isJoin) {
-            buff.append(" ON ");
+            buff.append("\n    ON ");
             if (joinCondition == null) {
                 // need to have a ON expression, otherwise the nesting is
                 // unclear
@@ -662,13 +668,13 @@ public class TableFilter implements ColumnResolver {
             }
         }
         if (filterCondition != null) {
-            buff.append(" /* WHERE ");
+            buff.append("\n");
             String condition = StringUtils.unEnclose(filterCondition.getSQL());
-            condition = StringUtils.quoteRemarkSQL(condition);
-            buff.append(condition).append(" */");
+            condition = "/* WHERE " + StringUtils.quoteRemarkSQL(condition) + "\n*/";
+            buff.append(StringUtils.indent(condition, 4, false));
         }
         if (scanCount > 0) {
-            buff.append(" /* scanCount: ").append(scanCount).append(" */");
+            buff.append("\n    /* scanCount: ").append(scanCount).append(" */");
         }
         return buff.toString();
     }

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

@@ -269,7 +269,7 @@ public class TableView extends Table {
 
     public String getSQL() {
         if (isTemporary()) {
-            return "(" + querySQL + ")";
+            return "(\n" + StringUtils.indent(querySQL) + ")";
         }
         return super.getSQL();
     }

h2/src/main/org/h2/util/StringUtils.java

@@ -582,20 +582,23 @@ public class StringUtils {
 
     /**
      * Indents a string with 4 spaces.
+     *
      * @param s the string
      * @return the indented string
      */
-    private static String indent(String s) {
-        return indent(s, 4);
+    public static String indent(String s) {
+        return indent(s, 4, true);
     }
 
     /**
      * Indents a string with spaces.
+     *
      * @param s the string
      * @param spaces the number of spaces
+     * @param newline append a newline if there is none
      * @return the indented string
      */
-    private static String indent(String s, int spaces) {
+    public static String indent(String s, int spaces, boolean newline) {
         StringBuilder buff = new StringBuilder(s.length() + spaces);
         for (int i = 0; i < s.length();) {
             for (int j = 0; j < spaces; j++) {
@@ -606,7 +609,7 @@ public class StringUtils {
             buff.append(s.substring(i, n));
             i = n;
         }
-        if (!s.endsWith("\n")) {
+        if (newline && !s.endsWith("\n")) {
             buff.append('\n');
         }
         return buff.toString();

h2/src/test/org/h2/samples/optimizations.sql

@@ -21,8 +21,10 @@ SELECT COUNT(*) FROM TEST;
 
 -- Display the query plan - 'direct lookup' means the index is used
 EXPLAIN SELECT COUNT(*) FROM TEST;
---> SELECT COUNT(*)
--->    FROM PUBLIC.TEST /* PUBLIC.TEST.tableScan */
+--> SELECT
+-->        COUNT(*)
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.TEST.tableScan */
 -->    /* direct lookup */
 ;
 
@@ -56,8 +58,10 @@ SELECT DISTINCT TYPE FROM TEST ORDER BY TYPE LIMIT 3;
 
 -- Display the query plan - 'index sorted' means the index is used to order
 EXPLAIN SELECT DISTINCT TYPE FROM TEST ORDER BY TYPE LIMIT 3;
---> SELECT DISTINCT TYPE
--->    FROM PUBLIC.TEST /* PUBLIC.IDX_TEST_TYPE */
+--> SELECT DISTINCT
+-->        TYPE
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.IDX_TEST_TYPE */
 -->    ORDER BY 1
 -->    LIMIT 3
 -->    /* distinct */
@@ -89,8 +93,11 @@ SELECT MIN(VALUE), MAX(VALUE) FROM TEST;
 
 -- Display the query plan - 'direct lookup' means it's optimized
 EXPLAIN SELECT MIN(VALUE), MAX(VALUE) FROM TEST;
---> SELECT MIN(VALUE), MAX(VALUE)
--->    FROM PUBLIC.TEST /* PUBLIC.TEST.tableScan */
+--> SELECT
+-->        MIN(VALUE),
+-->        MAX(VALUE)
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.TEST.tableScan */
 -->    /* direct lookup */
 ;
 
@@ -130,17 +137,29 @@ FROM (SELECT DISTINCT TYPE FROM TEST) T ORDER BY TYPE;
 EXPLAIN SELECT TYPE, (SELECT VALUE FROM TEST T2 WHERE T.TYPE = T2.TYPE
 ORDER BY TYPE, VALUE LIMIT 1) MIN
 FROM (SELECT DISTINCT TYPE FROM TEST) T ORDER BY TYPE;
---> SELECT TYPE, (SELECT VALUE
--->    FROM PUBLIC.TEST T2 /* PUBLIC.IDX_TEST_TYPE_VALUE: TYPE = T.TYPE */
--->    WHERE T.TYPE = T2.TYPE
--->    ORDER BY =TYPE, 1
--->    LIMIT 1
--->    /* index sorted */) AS MIN
--->    FROM (SELECT DISTINCT TYPE
--->    FROM PUBLIC.TEST /* PUBLIC.IDX_TEST_TYPE_VALUE */
--->    /* distinct */) T /* SELECT DISTINCT TYPE
--->    FROM PUBLIC.TEST /++ PUBLIC.IDX_TEST_TYPE_VALUE ++/
--->    /++ distinct ++/ */
+--> SELECT
+-->        TYPE,
+-->        (SELECT
+-->            VALUE
+-->        FROM PUBLIC.TEST T2
+-->            /* PUBLIC.IDX_TEST_TYPE_VALUE: TYPE = T.TYPE */
+-->        WHERE T.TYPE = T2.TYPE
+-->        ORDER BY =TYPE, 1
+-->        LIMIT 1
+-->        /* index sorted */) AS MIN
+-->    FROM (
+-->        SELECT DISTINCT
+-->            TYPE
+-->        FROM PUBLIC.TEST
+-->            /* PUBLIC.IDX_TEST_TYPE_VALUE */
+-->        /* distinct */
+-->    ) T
+-->        /* SELECT DISTINCT
+-->            TYPE
+-->        FROM PUBLIC.TEST
+-->            /++ PUBLIC.IDX_TEST_TYPE_VALUE ++/
+-->        /++ distinct ++/
+-->         */
 -->    ORDER BY 1
 ;
 
@@ -171,8 +190,10 @@ SELECT VALUE FROM TEST ORDER BY VALUE LIMIT 3;
 
 -- Display the query plan - 'index sorted' means the index is used
 EXPLAIN SELECT VALUE FROM TEST ORDER BY VALUE LIMIT 10;
---> SELECT VALUE
--->    FROM PUBLIC.TEST /* PUBLIC.IDX_TEST_VALUE */
+--> SELECT
+-->        VALUE
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.IDX_TEST_VALUE */
 -->    ORDER BY 1
 -->    LIMIT 10
 -->    /* index sorted */
@@ -190,8 +211,10 @@ SELECT VALUE FROM TEST ORDER BY VALUE DESC LIMIT 3;
 
 -- Display the query plan - 'index sorted' means the index is used
 EXPLAIN SELECT VALUE FROM TEST ORDER BY VALUE DESC LIMIT 10;
---> SELECT VALUE
--->    FROM PUBLIC.TEST /* PUBLIC.IDX_TEST_VALUE_D */
+--> SELECT
+-->        VALUE
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.IDX_TEST_VALUE_D */
 -->    ORDER BY 1 DESC
 -->    LIMIT 10
 -->    /* index sorted */
@@ -216,8 +239,10 @@ SELECT * FROM TEST WHERE ID IN(1, 1000);
 
 -- Display the query plan
 EXPLAIN SELECT * FROM TEST WHERE ID IN(1, 1000);
---> SELECT TEST.ID
--->    FROM PUBLIC.TEST /* PUBLIC.PRIMARY_KEY_2: ID IN(1, 1000) */
+--> SELECT
+-->        TEST.ID
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.PRIMARY_KEY_2: ID IN(1, 1000) */
 -->    WHERE ID IN(1, 1000)
 ;
 
@@ -236,9 +261,13 @@ INSERT INTO TEST SELECT X, MOD(X, 10) FROM SYSTEM_RANGE(1, 1000);
 
 -- Display the query plan
 EXPLAIN SELECT * FROM TEST WHERE ID IN (10, 20) AND DATA IN (1, 2);
---> SELECT TEST.ID, TEST.DATA
--->    FROM PUBLIC.TEST /* PUBLIC.PRIMARY_KEY_2: ID IN(10, 20) */
--->    WHERE (ID IN(10, 20)) AND (DATA IN(1, 2))
+--> SELECT
+-->        TEST.ID,
+-->        TEST.DATA
+-->    FROM PUBLIC.TEST
+-->        /* PUBLIC.PRIMARY_KEY_2: ID IN(10, 20) */
+-->    WHERE (ID IN(10, 20))
+-->        AND (DATA IN(1, 2))
 ;
 
 DROP TABLE TEST;

h2/src/test/org/h2/test/db/TestScript.java

@@ -259,7 +259,16 @@ public class TestScript extends TestBase {
         if (s == null) {
             return "null";
         }
-        return s.replace('\n', ' ');
+        s = s.replace('\n', ' ');
+        s = StringUtils.replaceAll(s, "    ", " ");
+        while (true) {
+            String s2 = StringUtils.replaceAll(s, "  ", " ");
+            if (s2.length() == s.length()) {
+                break;
+            }
+            s = s2;
+        }
+        return s;
     }
 
     private void writeResultSet(String sql, ResultSet rs) throws Exception {