enable clustered index by default for TiDB (#134)

* enable clustered index by default for TiDB

* change the syntax of cluster index to "/*T![clustered_index] CLUSTERED */"

tpcc/ddl.go

@@ -126,7 +126,7 @@ CREATE TABLE IF NOT EXISTS warehouse (
 	w_zip CHAR(9),
 	w_tax DECIMAL(4, 4),
 	w_ytd DECIMAL(12, 2),
-	PRIMARY KEY (w_id)
+	PRIMARY KEY (w_id) /*T![clustered_index] CLUSTERED */
 )`
 
 		query = w.appendPartition(query, "w_id")
@@ -149,7 +149,7 @@ CREATE TABLE IF NOT EXISTS district (
 	d_tax DECIMAL(4, 4),
 	d_ytd DECIMAL(12, 2),
 	d_next_o_id INT,
-	PRIMARY KEY (d_w_id, d_id)
+	PRIMARY KEY (d_w_id, d_id) /*T![clustered_index] CLUSTERED */
 )`
 
 		query = w.appendPartition(query, "d_w_id")
@@ -182,7 +182,7 @@ CREATE TABLE IF NOT EXISTS customer (
 	c_payment_cnt INT, 
 	c_delivery_cnt INT, 
 	c_data VARCHAR(500),
-	PRIMARY KEY(c_w_id, c_d_id, c_id),
+	PRIMARY KEY(c_w_id, c_d_id, c_id) /*T![clustered_index] CLUSTERED */,
 	INDEX idx_customer (c_w_id, c_d_id, c_last, c_first)
 )`
 
@@ -217,7 +217,7 @@ CREATE TABLE IF NOT EXISTS new_order (
 	no_o_id INT NOT NULL,
 	no_d_id INT NOT NULL,
 	no_w_id INT NOT NULL,
-	PRIMARY KEY(no_w_id, no_d_id, no_o_id)
+	PRIMARY KEY(no_w_id, no_d_id, no_o_id) /*T![clustered_index] CLUSTERED */
 )`
 
 		query = w.appendPartition(query, "no_w_id")
@@ -236,7 +236,7 @@ CREATE TABLE IF NOT EXISTS orders (
 	o_carrier_id INT,
 	o_ol_cnt INT,
 	o_all_local INT,
-	PRIMARY KEY(o_w_id, o_d_id, o_id),
+	PRIMARY KEY(o_w_id, o_d_id, o_id) /*T![clustered_index] CLUSTERED */,
 	INDEX idx_order (o_w_id, o_d_id, o_c_id, o_id)
 )`
 
@@ -257,7 +257,7 @@ CREATE TABLE IF NOT EXISTS orders (
 		ol_quantity INT,
 		ol_amount DECIMAL(6, 2),
 		ol_dist_info CHAR(24),
-		PRIMARY KEY(ol_w_id, ol_d_id, ol_o_id, ol_number)
+		PRIMARY KEY(ol_w_id, ol_d_id, ol_o_id, ol_number) /*T![clustered_index] CLUSTERED */
 )`
 
 		query = w.appendPartition(query, "ol_w_id")
@@ -284,7 +284,7 @@ CREATE TABLE IF NOT EXISTS stock (
 	s_order_cnt INT, 
 	s_remote_cnt INT,
 	s_data VARCHAR(50),
-	PRIMARY KEY(s_w_id, s_i_id)
+	PRIMARY KEY(s_w_id, s_i_id) /*T![clustered_index] CLUSTERED */
 )`
 
 		query = w.appendPartition(query, "s_w_id")
@@ -299,7 +299,7 @@ CREATE TABLE IF NOT EXISTS item (
 	i_name VARCHAR(24),
 	i_price DECIMAL(5, 2),
 	i_data VARCHAR(50),
-	PRIMARY KEY(i_id)
+	PRIMARY KEY(i_id) /*T![clustered_index] CLUSTERED */
 )`
 
 		if err := w.createTableDDL(ctx, query, tableItem); err != nil {