sec curity

|+---------------------------+24 rows in Set (0.00 sec)Well, we've learned some simple database operations, and then we're going to start creating our own databases, datasheets!Create a databaseSimple command:Create Database MyData;The result is:Query OK, 1 row Affected (0.00 sec)The prompt has been successful. Next we use the View Table command, show:Mysql> Show databases;+-----------

validation rules are changed, the existing tables are not affected by the modification;In the same vein as the already existing column ...mysql> CREATE DATABASE yutest0; Query OK, 1 row Affected (0.00 sec) mysql> use yutest0;database changedmysql> create table T1 (name varchar (10)); Query OK, 0 rows affected (0.01 sec) mysql> insert into T1 values (' AAA '); Query OK, 1 row Affected (0.00

/0 17 Serial0/1 26 active Serial0/1 26 Serial0/0 17 active Serial0/1 27 Serial0/2 36 active Serial0/2 36 Serial0/1 27 active Serial0/2 37 Serial0/0 16 active FR # show frame-relay pvc PVC Statistics for interface Serial0/0 (Frame Relay DCE) Active Inactive Deleted Static Local 0 0 0 0 Switched 2 0 0 0 Unused 0 0 0 0 DLCI = 16, dlci usage = SWITCHED, pvc status = ACTIVE, INTERFACE = Serial0/0 Input pkts 23 output pkts 22 in bytes 2170 Out bytes 2140 dropped pkts 0 in pkts dropped 0 Out pkts dropp

I just took the time to perform master-master synchronization for MySQL. Write down the steps and update them at any time for any problems. Here, the database I synchronized is test. 1. Environment Description. HOST: 192.168.0.231 () HOST: 192.168.0.20.( B) MySQL version 5.1.21 2. Authorize the user. A: Mysql> grant replication slave, file on *. * To 'repl1' @ '192. 168.0.20.' identified By '123 '; Query OK, 0 rows affected (0.00 Sec) Mysql> flush pr

5.6, we found that the alter column step is the same as the modify column step. Mysql>Create Table Xs (name varchar (12), age int default 5 );Query OK, 0 rows affected (0.34 Sec) Mysql>Insert into Xs values ('A', 4 );Query OK, 1 row affected (0.05 Sec) Mysql>Set profiling = 1;Query OK, 0 rows affected, 1 warning (0.01 Sec) Mysql>Alter table Xs modify age int not

/plainContent-Length: 12Connection: keep-aliveDate: Sun, 15 Dec 2013 15:00:15 GMTServer: gophr $ Curl-sI http://go.fcgi.unix/| wc-c141 Start the engine Use sysctl to configure the kernel Configure Nginx Configure Nginx vhosts Start the service with www-data Run the Benchmark Test Benchmark Test GOMAXPROCS = 1Go standalone # Wrk-t100-c5000-d30s http: // 127.0.0.1: 8080/Running 30 s test @ http: // 127.0.0.1: 8080/100 threads and 5000 connectionsThread Stats Avg Stdev Max ++/-StdevLatency 11

Counter is a data indicator that describes the performance of servers or operating systems. Counters play a key role in performance testing, especially when analyzing the scalability of the system and locating performance bottlenecks, the Analysis of counter values is critical. However, it must be noted that a single performance counter can only reflect one aspect of the system performance, and the analysis of the performance test results must be based on multiple different counters. Another ter

/hw_libo/article/details/40097125 The following experiment confirms:2. MyISAM table MySQL [bosco]> CREATE TABLE `t5` ( -> `id` int(10) unsigned NOT NULL AUTO_INCREMENT, -> PRIMARY KEY (`id`) -> ) ENGINE=MyISAM;Query OK, 0 rows affected (0.05 sec)MySQL [bosco]> insert into t5 values(null);Query OK, 1 row affected (0.07 sec)MySQL [bosco]> select * from t5;+----+| id |+----+| 1 |+----+1 row in se

encoded, MySQL's character-set-client is configured as GBK, and the table structure is charset = utf8, there will be no doubt there will be garbled characters. Here we will give a simple demonstration of this situation: Master [localhost] {msandbox} (test)> create table charset_test_utf8 (id int primary key auto_increment, char_col varchar (50) charset = utf8; Query OK, 0 rows affected (0.04 sec) master [localhost] {msandbox} (test)> set names gbk

Mysqlusetest1; ReadingtableinformationforcompletionoftableandcolumnnamesYoucanturnoffthisfeaturetogetaquickerstartupwith-ADatabasechangemysql mysql> use test1;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changemysql> select * from emp;+------------+----------+------+--------+| ename | hiredate | sal | deptno |+------------+----------+------+--------+| aaaaa | NULL | NULL | 1 || ccccccc

MASTER-MASTER cyclic synchronization from the MASTER node of MYSQL to the MASTER node. However, being prepared will have a certain impact on performance! Write down the steps and update them at any time for any problems. Here, the database I synchronized is TEST. 1. environment description. Host: 192.168.0.231 () Host: 192.168.0.20.( B) MYSQL version 5.1.21 2. authorize the user. A: Mysql> grant replication slave, file on *. * to 'repl1' @ '192. 168.0.20.' identified By '123 '; Query OK, 0 rows

MySQL basics 06 data type (6) type conversion, mysql Data Type1.Cast () Usage In MySQL, cast (value as target type) syntax can be used for conversion of most types. Cast must be followed by left parentheses: Mysql> select cast (123 as char ); + ------------------- + | Cast (123 as char) | + ------------------- + | 1, 123 | + ------------------- + 1 row in set (0.00 sec) An error is reported when there is a space between cast and left parentheses: My

Just took the time to do a little MySQL master synchronization.Write down the steps, and as to what will happen, update at any time. The database I synchronized here is test1, environment description.Host: 192.168.0.231 (A)Host: 192.168.0.232 (B)MYSQL version for 5.1.212, authorized users.A:Mysql> Grant replication Slave,file on *.* to ' repl1 ' @ ' 192.168.0.232 ' identifiedBy ' 123456 ';Query OK, 0 rows Affected (0.00 sec)mysql> flush Privileges;Que

files have been written to:/root/mysql-5.5.34-spider-3.2-vp-1.1-hs-1.2-q4m-0.95 ==> Solution Yum Install Bison 4. Initialize the environment before starting: #根据实际情况调整 /usr/local/mysql/scripts/mysql_install_db \--DEFAULTS-FILE=/ETC/MY.CNF \--basedir=/usr/local/mysql \--datadir=/usr/local/mysql/data \--user=mysql 5. Choose one of the ways to start (here Mysql.server) Modify the variables inside the Mysql.server Basedir=/usr/local/mysqlDatadir=/usr/local/mysql/data #修改完成后./mysql.server Start Lib

Master-Slave synchronous maintenance Due to special circumstances, the main server updates frequently, from the server due to a variety of reasons, resulting in a particularly slow update, this situation, we need to regularly master and slave data synchronization maintenance, the specific methods are as follows, in the low load time temporarily blocking the main database update, forcing the master-slave database update synchronization Action 1, execute the following statement on master: Mysql>

Charset_test_utf8 (ID int primary key auto_increment, Char_col Varc Har (m) charset = UTF8;Query OK, 0 rows affected (0.04 sec) master [localhost] {msandbox} (Test) > Set names GBK;Query OK, 0 rows Affected (0.00 sec) master [localhost] {msandbox} (Test) > INSERT into Charset_test_utf8 (Char_col) VALUES ("Chinese");Query OK, 1 row affected, 1 warning (0.01 sec

{7 size_t Fir = 0, sec = pos;8 while (Fir 9 {Ten while (Fir size_t maxmove = 0;(Sec T_exchange ( V[fir], Sec-fir, sec-fir-maxmove);Fir + = Maxmove;15}16}where T is an array, size is an array dimension, and POS is the location of the merge Division. that is, [0,pos] and [POS, size] are ordered respectively. For example

or interchange table Auto_increment will happen reset Specific operation:PT is a partitioned table, p is a partition or sub-partition1. Swap partitions with non-partitioned tablesCREATE TABLE e ( id INT NOT NULL, fname VARCHAR(30), lname VARCHAR(30) ) PARTITION BY RANGE (id) ( PARTITION p0 VALUES LESS THAN (50), PARTITION p1 VALUES LESS THAN (100), PARTITION p2 VALUES LESS THAN (150), PARTITION p3 VALUES LESS THA

password displayed in the database is saved in the form of ciphertext, greatly enhanced securitymysql> select User,authentication_string,Host from user;+-----------+-------------------------------------------+-----------+| User | authentication_string | Host |+-----------+-------------------------------------------+-----------+| root | *0DB339632B48910F8F0BEF61BD7EAD4441267E6E | localhost || mysql.sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | localhost |+-

steps, as long as two or more than two of the code is inconsistent, there is a possibility of codec error. If a lossless encoding conversion between the two character sets of the difference is not possible (described in more detail below), garbled characters are bound to occur. For example: Our shell is UTF8 encoding, MySQL character-set-client configuration into a GBK, and the table structure is charset=utf8 , then there will undoubtedly be garbled.So here's a quick demonstration of the situat