MongoDB cheatsheet

MongoDB is an NoSQL document-oriented database program. These are my quick notes to support MongoDB. How to install MongoDB Enterprise on Red Hat Linux --create a repo file and insert the text below vi /etc/yum.repos.d/mongodb-enterprise.repo [mongodb-enterprise] name=MongoDB Enterprise Repository baseurl=https://repo.mongodb.com/yum/redhat/$releasever/mongodb-enterprise/3.4/$basearch/ gpgcheck=1 enabled=1 gpgkey=https://www.mongodb.org/static/pgp/server-3.4.asc --install the package sudo yum install -y mongodb-enterprise Log Into MongoDB mongo - -p --authenticationDatabase Show all DBs show dbs Create the user Administrator Note:Once you've created the admin Users, you'll need to disconnect from the Mongo Shell & restart the Mongo Server use admin db.createUser( { user: "myUserAdmin", pwd: "abc123", roles: [ {... Read more →

How to use an external smtp server with Linux mail \ mailx

Question: How can I use an external smtp server with Linux mail ? I'm using the heirloom-mailx implementation on RHEL. Answer: Here are some examples of using an external smtp server, using the heirloom package on RHEL. --sending an email to an external smtp server - with an attachment mail -v -r "root@myserver.net" -s "Test Email with attachment" -S smtp="smtp-xxxx.xxxx.xxxx.net" -a/tmp/hi_jack.txt "jack@xxxxxx.com" --sending an email to an external smtp server with multiple recipients mail -v -r "root@mysever.net" -s "Test Email with attachment" -S smtp="smtp-xxxx.xxxx.xxxx.net" -a/tmp/hi_jack.txt "jack@xxxx.com,kevin@xxxx.com" --sending an email to an external smtp with message written to body echo "Hi... Read more →

How to list extensions in PostgreSQL

Question: I've added an extension on PostgreSQL during the creation of a DBLink extension for cross database queries. The command I've executed is CREATE EXTENSION dblink. How can I list all the extensions within the PostgreSQL db , to confirm the extension is registered? Answer: To view information on PostgreSQL extensions you can either use the psql command or you can use some sql code >>psql method \dx >>sql code method select * FROM pg_extension; >>view available extensions select * FROM pg_available_extensions Read more →

Frequently Asked Questions - dba-ninja.com

I've compiled a list of the questions that I get asked most frequently. If you have a question that I haven't answered or you need a more detailed answer, you can comment on contact me. Please read through to see if I've answered it already. FAQs were lasted updated on 6th December 2017. Do you accept sponsored posts? Yes , sponsored posts are accepted. The content must be relevant to http://www.dba-ninja.com readers. The sponsored post package includes: -Published post on dba-ninja.com -Social media promotion – twitter.com, LinkedIn , Google Plus+Jack Vamvas -Promotion in dba-ninja.com email newsletter -Extra links within http://www.dba-ninja.com... Read more →

Contact me Jack Vamvas

Jack Vamvas is a full time DBA with in depth experience of DB2 and SQL server. In the meantime , You can find Jack on twitter.com/jackvamvas, LinkedIn , +Jack Vamvas , http://www.dba-db2.com , http://www.sqlserver-dba.com I specialise in Tuning, Optimisation, SQL Programming, database design and also involved in a fullrange of database management procedures. I work for a number of Top 100 companies specialising in managing large database environments - using multiple database platforms such as DB2, SQL Server and PostgreSQL environments Improve SQL Server, DB2 ,PostgreQL,MariaDB and MongoDB performance. I identify and solve bottlenecks fast. Cut through the complexity with... Read more →

PostgreSQL cheatsheet

--quit from psql \q --version select version(); --Create PostgreSQL database create database MYDB owner myowner; --drop PostgreSQL database.BE CAREFUL USING THIS COMMAND - IT CANNOT BE REVERSED!! TAKE A BACKUP FIRST drop database MYDB; --list PostgreSQL databases \list \l --list tables \dt --list all tables,views,sequences \dtvs the_schema.* --create a schema CREATE SCHEMA myschema; --list all schemas in a databases select nspname from pg_catalog.pg_namespace; --list all tables in a particular schema \dt public.* --columns in a table \d+ my_table_name --change the schema for a table ALTER TABLE myTable SET SCHEMA myschema; --change the schema for a SEQUENCE ALTER SEQUENCE mysequence SET... Read more →

Open Source database links

MySQL Might Be Right for Uber, but Not for You - DZone Database Read more →