diff --git a/docs/linux/network.md b/docs/linux/network.md
index 3eb6a77..6d5d34f 100644
--- a/docs/linux/network.md
+++ b/docs/linux/network.md
@@ -15,3 +15,33 @@ iptables -L -vn
 # Fix TTL for mobile network
 iptables -t mangle -A POSTROUTING -j TTL --ttl-set 65
 ```
+
+## TC
+```bash
+#!/bin/bash
+
+	interface=veth0
+
+	interface_limit=100mbit
+	 download_limit=40mbit
+	   upload_limit=40mbit
+
+	# tc -s -d qdisc show dev veth0
+
+	tc qdisc show dev $interface | grep -q "qdisc pfifo_fast 0"
+	[ "$?" -gt "0" ] && tc qdisc del dev $interface root; sleep 1
+
+	tc qdisc add dev $interface root handle 1: htb default 30
+
+	tc class add dev $interface parent 1:  classid 1:1  htb rate $interface_limit burst 15k
+	tc class add dev $interface parent 1:1 classid 1:10 htb rate  $download_limit burst 15k
+	tc class add dev $interface parent 1:1 classid 1:20 htb rate    $upload_limit burst 15k
+
+	tc qdisc add dev $interface parent 1:10 handle 10: sfq perturb 10
+	tc qdisc add dev $interface parent 1:20 handle 20: sfq perturb 10
+
+	tc filter add dev $interface protocol ip parent 1: prio 1 u32 match ip dst 0.0.0.0/0 flowid 1:10
+	tc filter add dev $interface protocol ip parent 1: prio 1 u32 match ip src 0.0.0.0/0 flowid 1:20
+
+```
+
diff --git a/docs/progs/mariadb.md b/docs/progs/mariadb.md
index 28d9456..8e41172 100644
--- a/docs/progs/mariadb.md
+++ b/docs/progs/mariadb.md
@@ -16,5 +16,9 @@ done
 
 ## Append field in table
 ```sql
-ALTER TABLE existsTableName ADD COLUMN `newFieldName` varchar(64) NOT NULL DEFAULT '';
+CREATE TABLE tableName_new AS (SELECT * FROM tableName);
+
+ALTER TABLE tableName_new ADD COLUMN `newFieldName` varchar(64) NOT NULL DEFAULT '' AFTER `existFieldName`;
+
+RENAME TABLE tableName TO tableName_old; RENAME TABLE tableName_new TO tableName;
 ```