1. Install JDK: add-apt-repository ppa:openjdk-r/ppa
apt-get update
apt-get install -y openjdk-8-jdk unzip
java -version #Check version
vi /etc/security/limits.conf #Append at the bottom; if 65535 already exists, change to 65 …
Modify the configuration file and add skip_grant_tables. Edit the configuration file:
vi /etc/my.cnf
Add the following under the [mysqld] section of the configuration file:
skip_grant_tables
Restart MySQL:
service mysqld restart
Access the database without a password and set a new one. Enter without a password:
mysql …
Error message as follows:
Error when connecting to server: Your password has expired. To log in you must change it using a client that supports expired passwords.
Log into mysql, set a new password, and set it to never expire:
my …
mysqlslap connection test error as follows:
mysqlslap: Cannot run query INSERT INTO t1 VALUES (73673339,'BN3152Gza4GW7atxJKACYwJqDbFynLxqc0kh30YTwgz3FktQ43XTrqJ4PQ25frn7kXhfXD8RuzN1j8Rf3y8ugKy6es3IbqPJM6y …
MySQL comes with its own stress-testing tool, mysqlslap.
Here is an example testing 500 concurrent connections and running the test 10 times:
mysqlslap -a -c 500 -i 10 -uroot -p123456
The results are as follows:
…
Query statement: replace “database” with your own database name
select
table_schema as 'Database',
table_name as 'Table Name',
table_rows as 'Row Count',
truncate(data_length/1024/1024, 2) as 'Data …
Software Download Address:
http://mirror.cnop.net/oracle/PLSQL_install.zip
or
http://share.cnop.net/file426/1806028-428340587
1. Extract and place this archive in the root directory of the system D drive:
2. Set Environment Variables:
User Variable Settings: Right-click My Computer …
Install dependency packages yum install -y centos-release-scl devtoolset-4-gcc-c++ devtoolset-4-gcc cmake openssl-devel bison git gmock ncurses ncurses-* autoconf
Create account groupadd mysql && useradd -r -g mysq …
Disable foreign key checks:
SET FOREIGN_KEY_CHECKS=0
Enable foreign key checks:
SET FOREIGN_KEY_CHECKS=1 …
Sometimes queried data needs to be detailed down to daily statistics. The statement is as follows and can be modified according to your situation:
Taking the user table as an example, query daily signup counts and group by day. The signupTime field is a date in the format “2019-09-05 00:38:17”:
Query statement: select DATE_FORMAT(signup …
