Jakir Hussain's Blog

A typical install of OS X won't create a .bash_profile for you. When you want to run functions from your command line, this is a must-have. Start up Terminal Type "cd ~/" to go to your home folder Type "touch .bash_profile" to create your new file. Edit .bash_profile with your favorite editor (or you can just type "open -e .bash_profile" to open it in TextEdit. Type ". .bash_profile" to reload .bash_profile and update any functions you add.

ACID (an acronymn for Atomicity Consistency Isolation Durability) is a concept that Database Professionals generally look for when evaluating databases and application architectures. For a reliable database all this four attributes should be achieved. Transaction must be  Atomic -  it is one unit of work and does not dependent  on previous and following transactions. Consistent -  data is either committed or  roll back, no “in-between” case where something has been updated and  something hasn’t. Isolated -  no transaction sees the intermediate results of the  current transaction. Durable -  the values persist if the data had been committed  even if the system crashes right after.

Mutable and immutable are English words meaning "can change" and "cannot change" respectively. The meaning of the words is the same in the IT context; i.e. a mutable String can be changed, and an immutable String cannot be changed. Good artical on  Immutability in C#