Refactor JDBC adapter related code

core/src/integration-test/java/com/scalar/db/storage/jdbc/JdbcEnv.java

@@ -37,10 +37,6 @@ public static Properties getProperties(String testName) {
   }
 
   public static boolean isSqlite() {
-    Properties properties = new Properties();
-    properties.setProperty(
-        DatabaseConfig.CONTACT_POINTS, System.getProperty(PROP_JDBC_URL, DEFAULT_JDBC_URL));
-    properties.setProperty(DatabaseConfig.STORAGE, "jdbc");
-    return JdbcUtils.isSqlite(new JdbcConfig(new DatabaseConfig(properties)));
+    return System.getProperty(PROP_JDBC_URL, DEFAULT_JDBC_URL).startsWith("jdbc:sqlite:");
   }
 }

core/src/integration-test/java/com/scalar/db/storage/jdbc/JdbcSchemaLoaderImportIntegrationTest.java

@@ -26,8 +26,7 @@ public class JdbcSchemaLoaderImportIntegrationTest extends SchemaLoaderImportInt
 
   @Override
   protected Properties getProperties(String testName) {
-    Properties properties = new Properties();
-    properties.putAll(JdbcEnv.getProperties(testName));
+    Properties properties = JdbcEnv.getProperties(testName);
     JdbcConfig config = new JdbcConfig(new DatabaseConfig(properties));
     rdbEngine = RdbEngineFactory.create(config);
     testUtils = new JdbcAdminImportTestUtils(properties);

core/src/main/java/com/scalar/db/storage/jdbc/JdbcUtils.java

@@ -130,10 +130,6 @@ public static BasicDataSource initDataSourceForAdmin(
     return dataSource;
   }
 
-  public static boolean isSqlite(JdbcConfig config) {
-    return config.getJdbcUrl().startsWith("jdbc:sqlite:");
-  }
-
   /**
    * Get {@code JDBCType} of the specified {@code sqlType}.
    *

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineDb2.java

@@ -14,7 +14,7 @@
 import com.scalar.db.io.TimeColumn;
 import com.scalar.db.io.TimestampColumn;
 import com.scalar.db.io.TimestampTZColumn;
-import com.scalar.db.storage.jdbc.query.MergeIntoQuery;
+import com.scalar.db.storage.jdbc.query.MergeQuery;
 import com.scalar.db.storage.jdbc.query.SelectQuery;
 import com.scalar.db.storage.jdbc.query.SelectWithLimitQuery;
 import com.scalar.db.storage.jdbc.query.UpsertQuery;
@@ -297,13 +297,13 @@ public String tryAddIfNotExistsToCreateIndexSql(String createIndexSql) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithLimitQuery(builder, limit);
   }
 
   @Override
   public UpsertQuery buildUpsertQuery(UpsertQuery.Builder builder) {
-    return MergeIntoQuery.createForDb2(builder);
+    return new MergeQuery(builder, "SYSIBM.DUAL");
   }
 
   @Override

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineMysql.java

@@ -141,7 +141,7 @@ public String enclose(String name) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithLimitQuery(builder, limit);
   }
 

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineOracle.java

@@ -8,7 +8,7 @@
 import com.scalar.db.common.CoreError;
 import com.scalar.db.exception.storage.ExecutionException;
 import com.scalar.db.io.DataType;
-import com.scalar.db.storage.jdbc.query.MergeIntoQuery;
+import com.scalar.db.storage.jdbc.query.MergeQuery;
 import com.scalar.db.storage.jdbc.query.SelectQuery;
 import com.scalar.db.storage.jdbc.query.SelectWithFetchFirstNRowsOnly;
 import com.scalar.db.storage.jdbc.query.UpsertQuery;
@@ -169,13 +169,13 @@ public String enclose(String name) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithFetchFirstNRowsOnly(builder, limit);
   }
 
   @Override
   public UpsertQuery buildUpsertQuery(UpsertQuery.Builder builder) {
-    return MergeIntoQuery.createForOracle(builder);
+    return new MergeQuery(builder, "DUAL");
   }
 
   @Override

core/src/main/java/com/scalar/db/storage/jdbc/RdbEnginePostgresql.java

@@ -181,7 +181,7 @@ public String enclose(String name) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithLimitQuery(builder, limit);
   }
 

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineSqlServer.java

@@ -161,13 +161,13 @@ public String enclose(String name) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithTop(builder, limit);
   }
 
   @Override
   public UpsertQuery buildUpsertQuery(UpsertQuery.Builder builder) {
-    return new MergeQuery(builder);
+    return new MergeQuery(builder, null, true);
   }
 
   @Override

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineSqlite.java

@@ -277,7 +277,7 @@ public String encloseFullTableName(String schema, String table) {
   }
 
   @Override
-  public SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit) {
+  public SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit) {
     return new SelectWithLimitQuery(builder, limit);
   }
 

core/src/main/java/com/scalar/db/storage/jdbc/RdbEngineStrategy.java

@@ -127,7 +127,7 @@ default String encloseFullTableName(String schema, String table) {
     return enclose(schema) + "." + enclose(table);
   }
 
-  SelectQuery buildSelectQuery(SelectQuery.Builder builder, int limit);
+  SelectQuery buildSelectWithLimitQuery(SelectQuery.Builder builder, int limit);
 
   UpsertQuery buildUpsertQuery(UpsertQuery.Builder builder);
 

core/src/main/java/com/scalar/db/storage/jdbc/query/MergeQuery.java

@@ -12,6 +12,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Collectors;
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 @ThreadSafe
@@ -24,16 +25,25 @@ public class MergeQuery implements UpsertQuery {
   private final Key partitionKey;
   private final Optional<Key> clusteringKey;
   private final Map<String, Column<?>> columns;
+  @Nullable private final String dualTableName;
+  private final boolean semicolonAdded;
 
   @SuppressFBWarnings("EI_EXPOSE_REP2")
-  public MergeQuery(Builder builder) {
+  public MergeQuery(Builder builder, @Nullable String dualTableName) {
+    this(builder, dualTableName, false);
+  }
+
+  @SuppressFBWarnings("EI_EXPOSE_REP2")
+  public MergeQuery(Builder builder, @Nullable String dualTableName, boolean semicolonAdded) {
     rdbEngine = builder.rdbEngine;
     schema = builder.schema;
     table = builder.table;
     tableMetadata = builder.tableMetadata;
     partitionKey = builder.partitionKey;
     clusteringKey = builder.clusteringKey;
     columns = builder.columns;
+    this.dualTableName = dualTableName;
+    this.semicolonAdded = semicolonAdded;
   }
 
   @Override
@@ -47,20 +57,23 @@ public String sql() {
         columns.keySet().stream().map(rdbEngine::enclose).collect(Collectors.toList());
 
     StringBuilder sql = new StringBuilder();
-    sql.append("MERGE ")
+    sql.append("MERGE INTO ")
         .append(rdbEngine.encloseFullTableName(schema, table))
         .append(" t1 USING (SELECT ")
-        .append(makeUsingSelectSqlString(enclosedKeyNames))
-        .append(") t2 ON (")
-        .append(makePrimaryKeyConditionsSqlString(enclosedKeyNames))
-        .append(")");
+        .append(makeUsingSelectSqlString(enclosedKeyNames));
+    if (dualTableName != null) {
+      sql.append(" FROM ").append(dualTableName);
+    }
+    sql.append(") t2 ON (").append(makePrimaryKeyConditionsSqlString(enclosedKeyNames)).append(")");
     if (!columns.isEmpty()) {
       sql.append(" WHEN MATCHED THEN UPDATE SET ")
           .append(makeUpdateSetSqlString(enclosedValueNames));
     }
     sql.append(" WHEN NOT MATCHED THEN INSERT ")
-        .append(makeInsertSqlString(enclosedKeyNames, enclosedValueNames))
-        .append(";");
+        .append(makeInsertSqlString(enclosedKeyNames, enclosedValueNames));
+    if (semicolonAdded) {
+      sql.append(";");
+    }
     return sql.toString();
   }
 

core/src/main/java/com/scalar/db/storage/jdbc/query/SelectQuery.java

@@ -152,7 +152,7 @@ public Builder limit(int limit) {
 
     public SelectQuery build() {
       if (limit > 0) {
-        return rdbEngine.buildSelectQuery(this, limit);
+        return rdbEngine.buildSelectWithLimitQuery(this, limit);
       }
       return new SimpleSelectQuery(this);
     }