MariaDB RLIKE condition

Question: I'm having a problem using RLIKE and searching for a hyphen '-' , within a string.Also some other problems related to identifying strings with both character and numeric , while excluding numeric only or letters only strings. These are some examples of the strings: Example 1 : Digit followed by letter – 12B, 110A , 78B, 2150A, 287H, 941C Example 2: Numbers or numbers/letter with hyphen separator eg 61-63, 98-99, 1-33,2-14,1A-2A,169-173 Example 3: Numbers with forward slash separator e.g 1B/32,142/8 ,336C/2 Could you give me some RLIKE examples for each of the above scenarios Answer: The following are simple... Read more →

MongoDB Replica Set High Availability Notes

MongoDB offers a strong solution for High Availability via the Replica Set High Availability setup. DBAs work with HA and become familiar with the behaviour during setup and management, there is also a requirement to communicate with application teams some of the HA behaviour. Developers can use this information to design their applications In the examples below - we are using a 3 node cluster set. A 3 node cluster replica set has a fault tolerance supporting unavailability of 1 node while still having a Primary Node and the ability to still write to the Primary. If 2 nodes become... Read more →

mongo : command not found

Question: I've installed the mongo as part of a replicaset . The server is part of a 3 - node replicaset and I can manage through MongoDB Operations Manager. But when i get onto the command line and type "mongo" , I'm getting the -bash: mongo: command not found. How can I fix this issue - as I'd like to be able to have the command line option Answer: Assuming everything is running as expected - the most likely reason is that the relevant mongo binaries are not in the /usr/bin folder. I've had this problem a few times and... Read more →