Remove DbSettings.largeTransactions

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

@@ -130,12 +130,6 @@ public class DbSettings extends SettingsBase {
      */
     public final boolean functionsInSchema = get("FUNCTIONS_IN_SCHEMA", true);
 
-    /**
-     * Database setting <code>LARGE_TRANSACTIONS</code> (default: true).<br />
-     * Support very large transactions
-     */
-    public final boolean largeTransactions = get("LARGE_TRANSACTIONS", true);
-
     /**
      * Database setting <code>LOB_TIMEOUT</code> (default: 300000,
      * which means 5 minutes).<br />

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

@@ -8,7 +8,6 @@ package org.h2.engine;
 import java.util.ArrayList;
 import java.util.HashMap;
 
-import org.h2.message.DbException;
 import org.h2.store.Data;
 import org.h2.store.FileStore;
 import org.h2.table.Table;
@@ -27,7 +26,6 @@ public class UndoLog {
     private int memoryUndo;
     private int storedEntries;
     private HashMap<Integer, Table> tables;
-    private final boolean largeTransactions;
 
     /**
      * Create a new undo log for the given session.
@@ -36,7 +34,6 @@ public class UndoLog {
      */
     UndoLog(Session session) {
         this.database = session.getDatabase();
-        largeTransactions = database.getSettings().largeTransactions;
     }
 
     /**
@@ -45,14 +42,8 @@ public class UndoLog {
      * @return the number of rows
      */
     int size() {
-        if (largeTransactions) {
         return storedEntries + records.size();
     }
-        if (SysProperties.CHECK && memoryUndo > records.size()) {
-            DbException.throwInternalError();
-        }
-        return records.size();
-    }
 
     /**
      * Clear the undo log. This method is called after the transaction is
@@ -77,7 +68,6 @@ public class UndoLog {
      */
     public UndoLogRecord getLast() {
         int i = records.size() - 1;
-        if (largeTransactions) {
         if (i < 0 && storedEntries > 0) {
             int last = storedEntriesPos.size() - 1;
             long pos = storedEntriesPos.remove(last);
@@ -96,7 +86,6 @@ public class UndoLog {
             file.seek(pos);
         }
         i = records.size() - 1;
-        }
         UndoLogRecord entry = records.get(i);
         if (entry.isStored()) {
             int start = Math.max(0, i - database.getMaxMemoryUndo() / 2);
@@ -152,7 +141,6 @@ public class UndoLog {
      */
     void add(UndoLogRecord entry) {
         records.add(entry);
-        if (largeTransactions) {
         memoryUndo++;
         if (memoryUndo > database.getMaxMemoryUndo() &&
                 database.isPersistent() &&
@@ -179,36 +167,6 @@ public class UndoLog {
             records.clear();
             file.autoDelete();
         }
-        } else {
-            if (!entry.isStored()) {
-                memoryUndo++;
-            }
-            if (memoryUndo > database.getMaxMemoryUndo() &&
-                    database.isPersistent() &&
-                    !database.isMVStore()) {
-                if (file == null) {
-                    String fileName = database.createTempFile();
-                    file = database.openFile(fileName, "rw", false);
-                    file.setCheckedWriting(false);
-                    file.seek(FileStore.HEADER_LENGTH);
-                    rowBuff = Data.create(database, Constants.DEFAULT_PAGE_SIZE);
-                    Data buff = rowBuff;
-                    for (UndoLogRecord r : records) {
-                        saveIfPossible(r, buff);
-                    }
-                } else {
-                    saveIfPossible(entry, rowBuff);
-                }
-                file.autoDelete();
-            }
-        }
-    }
-
-    private void saveIfPossible(UndoLogRecord r, Data buff) {
-        if (!r.isStored() && r.canStore()) {
-            r.save(buff, file, this);
-            memoryUndo--;
-        }
     }
 
     /**

h2/src/test/org/h2/test/todo/TestUndoLogMemory.java

-/*
- * Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
- * and the EPL 1.0 (http://h2database.com/html/license.html).
- * Initial Developer: H2 Group
- */
-package org.h2.test.todo;
-
-import java.sql.Connection;
-import java.sql.DriverManager;
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-import java.sql.Statement;
-import org.h2.tools.DeleteDbFiles;
-
-/**
- * A test to reproduce out of memory using a large operation.
- */
-public class TestUndoLogMemory {
-
-    /**
-     * Run just this test.
-     *
-     * @param args ignored
-     */
-    public static void main(String... args) throws Exception {
-        TestUndoLogMemory.test(10, "null");
-        TestUndoLogMemory.test(100, "space(100000)");
-        // new TestUndoLogMemory().test(100000, "null");
-        // new TestUndoLogMemory().test(1000, "space(100000)");
-    }
-
-    private static void test(int count, String defaultValue) throws SQLException {
-
-        // -Xmx1m -XX:+HeapDumpOnOutOfMemoryError
-        DeleteDbFiles.execute("data", "test", true);
-        Connection conn = DriverManager.getConnection(
-                "jdbc:h2:data/test;large_transactions=true");
-        Statement stat = conn.createStatement();
-        stat.execute("set cache_size 32");
-        stat.execute("SET max_operation_memory 100");
-        stat.execute("SET max_memory_undo 100");
-        conn.setAutoCommit(false);
-
-        // also a problem: tables without unique index
-        System.out.println("create--- " + count + " " + defaultValue);
-        stat.execute("create table test(id int, name varchar default " +
-                defaultValue + " )");
-        System.out.println("insert---");
-        stat.execute("insert into test(id) select x from system_range(1, " +
-                count + ")");
-        System.out.println("rollback---");
-        conn.rollback();
-
-        System.out.println("drop---");
-        stat.execute("drop table test");
-        System.out.println("create---");
-        stat.execute("create table test" +
-                "(id int primary key, name varchar default " +
-                defaultValue + " )");
-
-        // INSERT problem
-        System.out.println("insert---");
-        stat.execute(
-            "insert into test(id) select x from system_range(1, "+count+")");
-        System.out.println("delete---");
-        stat.execute("delete from test");
-
-        // DELETE problem
-        System.out.println("insert---");
-        PreparedStatement prep = conn.prepareStatement(
-                "insert into test(id) values(?)");
-        for (int i = 0; i < count; i++) {
-            prep.setInt(1, i);
-            prep.execute();
-        }
-        System.out.println("delete---");
-        stat.execute("delete from test");
-
-        System.out.println("close---");
-        conn.close();
-    }
-
-}