Here I will give a good SQL statement, it can delete the duplicate records and leave the min id reco...
MYSQL date function: TO_DAYS() and FROM_DAYS()
1、to_days(date), change the date to a integer number days. mysql> SELECT TO_DAYS(950501); -> 728779 ...
MYSQL 8.0 ERROR:ERROR 2059: AUTHENTICATION PLUGIN ‘CACHING_SHA2_PASSWORD’ CANNOT BE LOADED
Error Message: error 2059: Authentication plugin ‘caching_sha2_password’ cannot be loaded: /usr/lib6...
mongodb update command($inc/$set/$unset/$push/$pop/upsert/save)
In addition to replacement, only partial updates are needed for one or more documents. Atomic update...

MongoDB – Too Many open files
Mongodb always meat the error too many open files, then the deam process crashed. In Linux system, t...

Install pycurl problems
install pycurl with problems curl-config and ssl libs In centos 7 and python 3.6 environment, instal...
Install Pycurl deal some possible problems
In Centos 7 system, Python 3.6 environment, use pip3 install the pycurl modal, may have two problems...
CANNOT OPEN SHARED OBJECT FILE: NO SUCH FILE OR DIRECTORY
This maybe you delete the shared lib file soft link. So must execute a system command to rebuild the...

Accelerating DNS parsing with pdnsd
Pdnsd is a good DNS parsing software in linux system. Compared with bind and dnsmasq, pdnsd has one ...