ISSUE-404 EXPLAIN should process statements with params placeholders. (#405)

* ISSUE-404 EXPLAIN should process statements with params placeholders.

* ISSUE-404 Fixed CommandRemote to support EXPLAIN with params placeholder.

* ISSUE-404 Fixed CommandRemote to support EXPLAIN with params placeholder.

* ISSUE-404 Support EXPLAIN with params placeholder WIP.

* ISSUE-404 Support EXPLAIN with params placeholder WIP.

* ISSUE-404 Support EXPLAIN with params placeholder WIP.

* ISSUE-404 Support EXPLAIN with params placeholder WIP.

* ISSUE-404 Muted tests.

* ISSUE-404 Fixed review notes.

* ISSUE-404 Un-muted tests.

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

@@ -55,9 +55,11 @@ public class CommandContainer extends Command {
 
     private static void prepareJoinBatch(Prepared prepared) {
         if (prepared.isQuery()) {
-            if (prepared.getType() == CommandInterface.SELECT) {
+            int type = prepared.getType();
+
+            if (type == CommandInterface.SELECT) {
                 ((Query) prepared).prepareJoinBatch();
-            } else if (prepared.getType() == CommandInterface.EXPLAIN) {
+            } else if (type == CommandInterface.EXPLAIN || type == CommandInterface.EXPLAIN_ANALYZE) {
                 prepareJoinBatch(((Explain) prepared).getCommand());
             }
         }

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

@@ -456,6 +456,11 @@ public interface CommandInterface {
      */
     int ALTER_TABLE_RENAME_CONSTRAINT = 85;
 
+    /**
+     * The type of a EXPLAIN ANALYZE statement.
+     */
+    int EXPLAIN_ANALYZE = 86;
+
     /**
      * Get command type.
      *

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

@@ -7,6 +7,8 @@ package org.h2.command;
 
 import java.io.IOException;
 import java.util.ArrayList;
+
+import org.h2.engine.Constants;
 import org.h2.engine.SessionRemote;
 import org.h2.engine.SysProperties;
 import org.h2.expression.ParameterInterface;
@@ -18,6 +20,7 @@ import org.h2.result.ResultRemote;
 import org.h2.util.New;
 import org.h2.value.Transfer;
 import org.h2.value.Value;
+import org.h2.value.ValueNull;
 
 /**
  * Represents the client-side part of a SQL statement.
@@ -33,6 +36,7 @@ public class CommandRemote implements CommandInterface {
     private SessionRemote session;
     private int id;
     private boolean isQuery;
+    private int cmdType = UNKNOWN;
     private boolean readonly;
     private final int created;
 
@@ -55,10 +59,13 @@ public class CommandRemote implements CommandInterface {
         for (int i = 0, count = 0; i < transferList.size(); i++) {
             try {
                 Transfer transfer = transferList.get(i);
+
+                boolean v16 = s.getClientVersion() >= Constants.TCP_PROTOCOL_VERSION_16;
+
                 if (createParams) {
-                    s.traceOperation("SESSION_PREPARE_READ_PARAMS", id);
+                    s.traceOperation(v16 ? "SESSION_PREPARE_READ_PARAMS2" : "SESSION_PREPARE_READ_PARAMS", id);
                     transfer.
-                        writeInt(SessionRemote.SESSION_PREPARE_READ_PARAMS).
+                        writeInt(v16 ? SessionRemote.SESSION_PREPARE_READ_PARAMS2 : SessionRemote.SESSION_PREPARE_READ_PARAMS).
                         writeInt(id).writeString(sql);
                 } else {
                     s.traceOperation("SESSION_PREPARE", id);
@@ -68,6 +75,9 @@ public class CommandRemote implements CommandInterface {
                 s.done(transfer);
                 isQuery = transfer.readBoolean();
                 readonly = transfer.readBoolean();
+
+                cmdType = v16 && createParams ? transfer.readInt() : UNKNOWN;
+
                 int paramCount = transfer.readInt();
                 if (createParams) {
                     parameters.clear();
@@ -203,8 +213,10 @@ public class CommandRemote implements CommandInterface {
     }
 
     private void checkParameters() {
-        for (ParameterInterface p : parameters) {
-            p.checkSet();
+        if (cmdType != EXPLAIN) {
+            for (ParameterInterface p : parameters) {
+                p.checkSet();
+            }
         }
     }
 
@@ -212,7 +224,12 @@ public class CommandRemote implements CommandInterface {
         int len = parameters.size();
         transfer.writeInt(len);
         for (ParameterInterface p : parameters) {
-            transfer.writeValue(p.getParamValue());
+            Value pVal = p.getParamValue();
+
+            if (pVal == null && cmdType == EXPLAIN)
+                pVal = ValueNull.INSTANCE;
+
+            transfer.writeValue(pVal);
         }
     }
 
@@ -260,7 +277,7 @@ public class CommandRemote implements CommandInterface {
 
     @Override
     public int getCommandType() {
-        return UNKNOWN;
+        return cmdType;
     }
 
 }

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

@@ -58,6 +58,13 @@ public class Explain extends Prepared {
         return query(-1);
     }
 
+    @Override
+    protected void checkParameters() {
+        // Check params only in case of EXPLAIN ANALYZE
+        if (executeCommand)
+            super.checkParameters();
+    }
+
     @Override
     public ResultInterface query(int maxrows) {
         Column column = new Column("PLAN", Value.STRING);
@@ -146,6 +153,6 @@ public class Explain extends Prepared {
 
     @Override
     public int getType() {
-        return CommandInterface.EXPLAIN;
+        return executeCommand ? CommandInterface.EXPLAIN_ANALYZE : CommandInterface.EXPLAIN;
     }
 }

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

@@ -96,6 +96,11 @@ public class Constants {
      */
     public static final int TCP_PROTOCOL_VERSION_15 = 15;
 
+    /**
+     * The TCP protocol version number 16.
+     */
+    public static final int TCP_PROTOCOL_VERSION_16 = 16;
+
     /**
      * The major version of this database.
      */

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

@@ -59,6 +59,7 @@ public class SessionRemote extends SessionWithState implements DataHandler {
     public static final int SESSION_SET_AUTOCOMMIT = 15;
     public static final int SESSION_HAS_PENDING_TRANSACTION = 16;
     public static final int LOB_READ = 17;
+    public static final int SESSION_PREPARE_READ_PARAMS2 = 18;
 
     public static final int STATUS_ERROR = 0;
     public static final int STATUS_OK = 1;
@@ -118,7 +119,7 @@ public class SessionRemote extends SessionWithState implements DataHandler {
         trans.setSSL(ci.isSSL());
         trans.init();
         trans.writeInt(Constants.TCP_PROTOCOL_VERSION_6);
-        trans.writeInt(Constants.TCP_PROTOCOL_VERSION_15);
+        trans.writeInt(Constants.TCP_PROTOCOL_VERSION_16);
         trans.writeString(db);
         trans.writeString(ci.getOriginalURL());
         trans.writeString(ci.getUserName());
@@ -217,6 +218,10 @@ public class SessionRemote extends SessionWithState implements DataHandler {
         }
     }
 
+    public int getClientVersion() {
+        return clientVersion;
+    }
+
     @Override
     public boolean getAutoCommit() {
         return autoCommit;

h2/src/main/org/h2/server/TcpServerThread.java

@@ -16,6 +16,7 @@ import java.sql.SQLException;
 import java.util.ArrayList;
 import org.h2.api.ErrorCode;
 import org.h2.command.Command;
+import org.h2.command.CommandInterface;
 import org.h2.engine.ConnectionInfo;
 import org.h2.engine.Constants;
 import org.h2.engine.Engine;
@@ -85,13 +86,13 @@ public class TcpServerThread implements Runnable {
                 if (minClientVersion < Constants.TCP_PROTOCOL_VERSION_6) {
                     throw DbException.get(ErrorCode.DRIVER_VERSION_ERROR_2,
                             "" + clientVersion, "" + Constants.TCP_PROTOCOL_VERSION_6);
-                } else if (minClientVersion > Constants.TCP_PROTOCOL_VERSION_15) {
+                } else if (minClientVersion > Constants.TCP_PROTOCOL_VERSION_16) {
                     throw DbException.get(ErrorCode.DRIVER_VERSION_ERROR_2,
-                            "" + clientVersion, "" + Constants.TCP_PROTOCOL_VERSION_15);
+                            "" + clientVersion, "" + Constants.TCP_PROTOCOL_VERSION_16);
                 }
                 int maxClientVersion = transfer.readInt();
-                if (maxClientVersion >= Constants.TCP_PROTOCOL_VERSION_15) {
-                    clientVersion = Constants.TCP_PROTOCOL_VERSION_15;
+                if (maxClientVersion >= Constants.TCP_PROTOCOL_VERSION_16) {
+                    clientVersion = Constants.TCP_PROTOCOL_VERSION_16;
                 } else {
                     clientVersion = minClientVersion;
                 }
@@ -256,6 +257,7 @@ public class TcpServerThread implements Runnable {
         int operation = transfer.readInt();
         switch (operation) {
         case SessionRemote.SESSION_PREPARE_READ_PARAMS:
+        case SessionRemote.SESSION_PREPARE_READ_PARAMS2:
         case SessionRemote.SESSION_PREPARE: {
             int id = transfer.readInt();
             String sql = transfer.readString();
@@ -264,10 +266,19 @@ public class TcpServerThread implements Runnable {
             boolean readonly = command.isReadOnly();
             cache.addObject(id, command);
             boolean isQuery = command.isQuery();
-            ArrayList<? extends ParameterInterface> params = command.getParameters();
+
             transfer.writeInt(getState(old)).writeBoolean(isQuery).
-                    writeBoolean(readonly).writeInt(params.size());
-            if (operation == SessionRemote.SESSION_PREPARE_READ_PARAMS) {
+                    writeBoolean(readonly);
+
+            if (operation == SessionRemote.SESSION_PREPARE_READ_PARAMS2) {
+                transfer.writeInt(command.getCommandType());
+            }
+
+            ArrayList<? extends ParameterInterface> params = command.getParameters();
+
+            transfer.writeInt(params.size());
+
+            if (operation != SessionRemote.SESSION_PREPARE) {
                 for (ParameterInterface p : params) {
                     ParameterRemote.writeMetaData(transfer, p);
                 }

h2/src/main/org/h2/store/FileLock.java

@@ -238,7 +238,7 @@ public class FileLock implements Runnable {
             transfer.setSocket(socket);
             transfer.init();
             transfer.writeInt(Constants.TCP_PROTOCOL_VERSION_6);
-            transfer.writeInt(Constants.TCP_PROTOCOL_VERSION_15);
+            transfer.writeInt(Constants.TCP_PROTOCOL_VERSION_16);
             transfer.writeString(null);
             transfer.writeString(null);
             transfer.writeString(id);

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

@@ -75,6 +75,8 @@ public class TestCases extends TestBase {
         testDeleteGroup();
         testDisconnect();
         testExecuteTrace();
+        testExplain();
+        testExplainAnalyze();
         if (config.memory) {
             return;
         }
@@ -897,6 +899,225 @@ public class TestCases extends TestBase {
         conn.close();
     }
 
+    private void checkExplain(Statement stat, String sql, String expected) throws SQLException {
+        ResultSet rs = stat.executeQuery(sql);
+
+        assertTrue(rs.next());
+
+        assertEquals(expected, rs.getString(1));
+    }
+
+    private void testExplain() throws SQLException {
+        deleteDb("cases");
+        Connection conn = getConnection("cases");
+        Statement stat = conn.createStatement();
+
+        stat.execute("CREATE TABLE ORGANIZATION(id int primary key, name varchar(100))");
+        stat.execute("CREATE TABLE PERSON(id int primary key, orgId int, name varchar(100), salary int)");
+
+        checkExplain(stat, "/* bla-bla */ EXPLAIN SELECT ID FROM ORGANIZATION WHERE id = ?",
+            "SELECT\n" +
+                "    ID\n" +
+                "FROM PUBLIC.ORGANIZATION\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = ?1 */\n" +
+                "WHERE ID = ?1");
+
+        checkExplain(stat, "EXPLAIN SELECT ID FROM ORGANIZATION WHERE id = 1",
+            "SELECT\n" +
+                "    ID\n" +
+                "FROM PUBLIC.ORGANIZATION\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = 1 */\n" +
+                "WHERE ID = 1");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE id = ?",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PRIMARY_KEY_8: ID = ?1 */\n" +
+                "WHERE ID = ?1");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE id = 50",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PRIMARY_KEY_8: ID = 50 */\n" +
+                "WHERE ID = 50");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE salary > ? and salary < ?",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PERSON.tableScan */\n" +
+                "WHERE (SALARY > ?1)\n" +
+                "    AND (SALARY < ?2)");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE salary > 1000 and salary < 2000",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PERSON.tableScan */\n" +
+                "WHERE (SALARY > 1000)\n" +
+                "    AND (SALARY < 2000)");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE name = lower(?)",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PERSON.tableScan */\n" +
+                "WHERE NAME = LOWER(?1)");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON WHERE name = lower('Smith')",
+            "SELECT\n" +
+                "    PERSON.ID,\n" +
+                "    PERSON.ORGID,\n" +
+                "    PERSON.NAME,\n" +
+                "    PERSON.SALARY\n" +
+                "FROM PUBLIC.PERSON\n" +
+                "    /* PUBLIC.PERSON.tableScan */\n" +
+                "WHERE NAME = 'smith'");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON p INNER JOIN ORGANIZATION o ON p.id = o.id WHERE o.id = ? AND p.salary > ?",
+            "SELECT\n" +
+                "    P.ID,\n" +
+                "    P.ORGID,\n" +
+                "    P.NAME,\n" +
+                "    P.SALARY,\n" +
+                "    O.ID,\n" +
+                "    O.NAME\n" +
+                "FROM PUBLIC.ORGANIZATION O\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = ?1 */\n" +
+                "    /* WHERE O.ID = ?1\n" +
+                "    */\n" +
+                "INNER JOIN PUBLIC.PERSON P\n" +
+                "    /* PUBLIC.PRIMARY_KEY_8: ID = O.ID */\n" +
+                "    ON 1=1\n" +
+                "WHERE (P.ID = O.ID)\n" +
+                "    AND ((O.ID = ?1)\n" +
+                "    AND (P.SALARY > ?2))");
+
+        checkExplain(stat, "EXPLAIN SELECT * FROM PERSON p INNER JOIN ORGANIZATION o ON p.id = o.id WHERE o.id = 10 AND p.salary > 1000",
+            "SELECT\n" +
+                "    P.ID,\n" +
+                "    P.ORGID,\n" +
+                "    P.NAME,\n" +
+                "    P.SALARY,\n" +
+                "    O.ID,\n" +
+                "    O.NAME\n" +
+                "FROM PUBLIC.ORGANIZATION O\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = 10 */\n" +
+                "    /* WHERE O.ID = 10\n" +
+                "    */\n" +
+                "INNER JOIN PUBLIC.PERSON P\n" +
+                "    /* PUBLIC.PRIMARY_KEY_8: ID = O.ID */\n" +
+                "    ON 1=1\n" +
+                "WHERE (P.ID = O.ID)\n" +
+                "    AND ((O.ID = 10)\n" +
+                "    AND (P.SALARY > 1000))");
+
+        PreparedStatement pStat = conn.prepareStatement("/* bla-bla */ EXPLAIN SELECT ID FROM ORGANIZATION WHERE id = ?");
+
+        ResultSet rs = pStat.executeQuery();
+
+        assertTrue(rs.next());
+
+        assertEquals("SELECT\n" +
+                "    ID\n" +
+                "FROM PUBLIC.ORGANIZATION\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = ?1 */\n" +
+                "WHERE ID = ?1",
+            rs.getString(1));
+
+        conn.close();
+    }
+
+    private void testExplainAnalyze() throws SQLException {
+        deleteDb("cases");
+        Connection conn = getConnection("cases");
+        Statement stat = conn.createStatement();
+
+        stat.execute("CREATE TABLE ORGANIZATION(id int primary key, name varchar(100))");
+        stat.execute("CREATE TABLE PERSON(id int primary key, orgId int, name varchar(100), salary int)");
+
+        stat.execute("INSERT INTO ORGANIZATION VALUES(1, 'org1')");
+        stat.execute("INSERT INTO ORGANIZATION VALUES(2, 'org2')");
+
+        stat.execute("INSERT INTO PERSON VALUES(1, 1, 'person1', 1000)");
+        stat.execute("INSERT INTO PERSON VALUES(2, 1, 'person2', 2000)");
+        stat.execute("INSERT INTO PERSON VALUES(3, 2, 'person3', 3000)");
+        stat.execute("INSERT INTO PERSON VALUES(4, 2, 'person4', 4000)");
+
+        assertThrows(ErrorCode.PARAMETER_NOT_SET_1, stat, "/* bla-bla */ EXPLAIN ANALYZE SELECT ID FROM ORGANIZATION WHERE id = ?");
+
+        PreparedStatement pStat = conn.prepareStatement("/* bla-bla */ EXPLAIN ANALYZE SELECT ID FROM ORGANIZATION WHERE id = ?");
+
+        assertThrows(ErrorCode.PARAMETER_NOT_SET_1, pStat).executeQuery();
+
+        pStat.setInt(1, 1);
+
+        ResultSet rs = pStat.executeQuery();
+
+        assertTrue(rs.next());
+
+        assertEquals("SELECT\n" +
+                "    ID\n" +
+                "FROM PUBLIC.ORGANIZATION\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = ?1 */\n" +
+                "    /* scanCount: 2 */\n" +
+                "WHERE ID = ?1",
+            rs.getString(1));
+
+        pStat = conn.prepareStatement("EXPLAIN ANALYZE SELECT * FROM PERSON p " +
+            "INNER JOIN ORGANIZATION o ON o.id = p.id WHERE o.id = ?");
+
+        assertThrows(ErrorCode.PARAMETER_NOT_SET_1, pStat).executeQuery();
+
+        pStat.setInt(1, 1);
+
+        rs = pStat.executeQuery();
+
+        assertTrue(rs.next());
+
+        assertEquals("SELECT\n" +
+                "    P.ID,\n" +
+                "    P.ORGID,\n" +
+                "    P.NAME,\n" +
+                "    P.SALARY,\n" +
+                "    O.ID,\n" +
+                "    O.NAME\n" +
+                "FROM PUBLIC.ORGANIZATION O\n" +
+                "    /* PUBLIC.PRIMARY_KEY_D: ID = ?1 */\n" +
+                "    /* WHERE O.ID = ?1\n" +
+                "    */\n" +
+                "    /* scanCount: 2 */\n" +
+                "INNER JOIN PUBLIC.PERSON P\n" +
+                "    /* PUBLIC.PRIMARY_KEY_8: ID = O.ID\n" +
+                "        AND ID = ?1\n" +
+                "     */\n" +
+                "    ON 1=1\n" +
+                "    /* scanCount: 2 */\n" +
+                "WHERE ((O.ID = ?1)\n" +
+                "    AND (O.ID = P.ID))\n" +
+                "    AND (P.ID = ?1)",
+            rs.getString(1));
+
+        conn.close();
+    }
+
     private void testAlterTableReconnect() throws SQLException {
         deleteDb("cases");
         Connection conn = getConnection("cases");
@@ -1530,4 +1751,4 @@ public class TestCases extends TestBase {
         conn.close();
     }
 
-}
+}
\ No newline at end of file