Unverified 提交 a729e2cd authored 作者: Evgenij Ryazanov's avatar Evgenij Ryazanov 提交者: GitHub

Merge pull request #1226 from katzyn/misc

Fix inconsistencies in checks for transaction isolation level
......@@ -229,7 +229,7 @@ Transaction isolation is provided for all data manipulation language (DML) state
<p>
Please note that with default MVStore storage engine table level locking is not used.
Instead, rows are locked for update, and read committed is used in all cases
(changing the isolation level has no effect).
except for explicitly selected read uncommitted transaction isolation level.
</p>
<p>
This database supports the following transaction isolation levels:
......@@ -247,7 +247,9 @@ This database supports the following transaction isolation levels:
To enable, execute the SQL statement <code>SET LOCK_MODE 1</code><br />
or append <code>;LOCK_MODE=1</code> to the database URL: <code>jdbc:h2:~/test;LOCK_MODE=1</code>
</li><li><b>Read Uncommitted</b><br />
This level means that transaction isolation is disabled.<br />
This level means that transaction isolation is disabled.
This level is not supported by PageStore engine if multi-threaded mode is enabled.
<br />
To enable, execute the SQL statement <code>SET LOCK_MODE 0</code><br />
or append <code>;LOCK_MODE=0</code> to the database URL: <code>jdbc:h2:~/test;LOCK_MODE=0</code>
</li>
......
......@@ -2265,12 +2265,12 @@ public class Database implements DataHandler {
switch (lockMode) {
case Constants.LOCK_MODE_OFF:
if (multiThreaded && !isMVStore()) {
// currently the combination of MVCC=FALSE, LOCK_MODE=0 and MULTI_THREADED
// is not supported. also see code in
// Currently the combination of MV_STORE=FALSE, LOCK_MODE=0 and
// MULTI_THREADED=TRUE is not supported. Also see code in
// JdbcDatabaseMetaData#supportsTransactionIsolationLevel(int)
throw DbException.get(
ErrorCode.UNSUPPORTED_SETTING_COMBINATION,
"MVCC=FALSE & LOCK_MODE=0 & MULTI_THREADED");
"MV_STORE=FALSE & LOCK_MODE=0 & MULTI_THREADED=TRUE");
}
break;
case Constants.LOCK_MODE_READ_COMMITTED:
......@@ -2457,12 +2457,12 @@ public class Database implements DataHandler {
public void setMultiThreaded(boolean multiThreaded) {
if (multiThreaded && this.multiThreaded != multiThreaded) {
if (lockMode == 0) {
// currently the combination of LOCK_MODE=0 and MULTI_THREADED
// is not supported
if (lockMode == Constants.LOCK_MODE_OFF && !isMVStore()) {
// Currently the combination of MV_STORE=FALSE, LOCK_MODE=0 and
// MULTI_THREADED=TRUE is not supported.
throw DbException.get(
ErrorCode.UNSUPPORTED_SETTING_COMBINATION,
"LOCK_MODE=0 & MULTI_THREADED");
"MV_STORE=FALSE & LOCK_MODE=0 & MULTI_THREADED=TRUE");
}
}
this.multiThreaded = multiThreaded;
......
......@@ -2315,16 +2315,31 @@ public class JdbcDatabaseMetaData extends TraceObject implements
@Override
public boolean supportsTransactionIsolationLevel(int level) throws SQLException {
debugCodeCall("supportsTransactionIsolationLevel");
if (level == Connection.TRANSACTION_READ_UNCOMMITTED) {
// currently the combination of LOCK_MODE=0 and MULTI_THREADED
// is not supported, also see code in Database#setLockMode(int)
PreparedStatement prep = conn.prepareAutoCloseStatement(
"SELECT VALUE FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME=?");
prep.setString(1, "MULTI_THREADED");
ResultSet rs = prep.executeQuery();
return !rs.next() || !rs.getString(1).equals("1");
switch (level) {
case Connection.TRANSACTION_READ_UNCOMMITTED: {
// Currently the combination of MV_STORE=FALSE, LOCK_MODE=0 and
// MULTI_THREADED=TRUE is not supported. Also see code in
// Database#setLockMode(int)
try (PreparedStatement prep = conn.prepareStatement(
"SELECT VALUE FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME=?")) {
// TODO skip MV_STORE check for H2 <= 1.4.197
prep.setString(1, "MV_STORE");
ResultSet rs = prep.executeQuery();
if (rs.next() && Boolean.parseBoolean(rs.getString(1))) {
return true;
}
prep.setString(1, "MULTI_THREADED");
rs = prep.executeQuery();
return !rs.next() || !rs.getString(1).equals("1");
}
}
case Connection.TRANSACTION_READ_COMMITTED:
case Connection.TRANSACTION_REPEATABLE_READ:
case Connection.TRANSACTION_SERIALIZABLE:
return true;
default:
return false;
}
return true;
}
/**
......
......@@ -292,7 +292,7 @@ public class LocalResult implements ResultInterface, ResultTarget {
private void createExternalResult() {
Database database = session.getDatabase();
external = database.getMvStore() != null
external = database.isMVStore()
? MVTempResult.of(database, expressions, distinct, sort)
: new ResultTempTable(session, expressions, distinct, sort);
}
......
......@@ -288,13 +288,12 @@ public class TestMultiThread extends TestDb implements Runnable {
}
private void testLockModeWithMultiThreaded() throws Exception {
// currently the combination of LOCK_MODE=0 and MULTI_THREADED
// is not supported
deleteDb("lockMode");
final String url = getURL("lockMode;MULTI_THREADED=1", true);
try (Connection conn = getConnection(url)) {
DatabaseMetaData meta = conn.getMetaData();
assertFalse(meta.supportsTransactionIsolationLevel(
// LOCK_MODE=0 with MULTI_THREADED=TRUE is supported only by MVStore
assertEquals(config.mvStore, meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_READ_UNCOMMITTED));
}
deleteDb("lockMode");
......
......@@ -611,14 +611,13 @@ public class TestMetaData extends TestDb {
assertTrue(meta.supportsSubqueriesInQuantifieds());
assertTrue(meta.supportsTableCorrelationNames());
assertTrue(meta.supportsTransactions());
assertTrue(meta.supportsTransactionIsolationLevel(
assertFalse(meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_NONE));
assertTrue(meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_READ_COMMITTED));
if (!config.multiThreaded) {
assertTrue(meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_READ_UNCOMMITTED));
}
assertEquals(config.mvStore || !config.multiThreaded,
meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_READ_UNCOMMITTED));
assertTrue(meta.supportsTransactionIsolationLevel(
Connection.TRANSACTION_REPEATABLE_READ));
assertTrue(meta.supportsTransactionIsolationLevel(
......
Markdown 格式
0%
您添加了 0 到此讨论。请谨慎行事。
请先完成此评论的编辑!
注册 或者 后发表评论