In this post, I would like to give a small overview of Clustered and Non-Clustered Indexes. DISCLAIMER: I am an Oracle employee, and the views/opinions expressed in the below article are purely my own and do not express the views of my employer. Let's start with similarities: Similarities: Both Clustered and Non-Clustered indexes are types... Continue Reading →
Primary Index v/s Secondary Index
In this very short post, I will give an overview of primary and secondary indexes in Databases. DISCLAIMER: I am an Oracle employee, and the views/opinions expressed in the below article are purely my own and do not express the views of my employer. Let me tell the similarities first: Similarities Both the index structures... Continue Reading →
Extendible Hashing
In the previous post, I had given a brief description of Linear Hashing technique. In this post, I will talk about Extendible Hashing. Like Linear Hashing, Extendible Hashing is also a dynamic hashing scheme. First let's talk a little bit about static and dynamic hashing as I had skipped this part in my previous post.... Continue Reading →
Linear Hashing
In this blog post, I will give an introduction to a hashing methodology called Linear Hashing. Hash Table Detour A hash table is a well known in-memory structure that supports key-value access with lookup cost being amortized O(1). The hash table is just an array, and each location/index in the array stores a <KEY,VALUE> item.... Continue Reading →
Pointer World !!
In this post, I will just give a brief overview of using pointers in several ways in our C/C++ programs. Pointer is sort of a known concept. Hence, the post will be focusing on the usage in various scenarios like arrays, strings, structs, functions along with code examples. Pointer to Pointer Pointers and Arrays Array... Continue Reading →
Logical and Physical Addresses
In this post, I am going to talk about logical and physical addressing of main memory (DRAM) in computer systems. Logical addresses are also known as virtual addresses. In fact, I would refer to them logical aka virtual aka unreal addresses. Yes, as the name suggests, logical addresses are unreal addresses. These are not the... Continue Reading →
Leader Election and Log Replication in Raft – Part 2
In the last part of this post, I gave a general overview of Raft followed by Leader Election algorithm. We now need to discuss, how leader does the consistent replication of log onto the follower nodes, few more safety properties, and constraints on the election mechanism. Log Replication For now let's assume that client requests... Continue Reading →
Leader Election and Log Replication in Raft – Part 1
In this post, I will talk about two critical components of Raft consensus algorithm. My post will majorly focus on the explanation of these concepts as I interpreted from this extremely good paper on Raft. Of few papers I have read, it is one of the most well written paper on distributed systems and related... Continue Reading →
Difference between Page table and Inverted Page table
A page table is maintained by the operating system on a per process basis. Every process has its own page table, and that is why we do not need to store any process identifier(s) in the page table. Page table maps a given logical/virtual page number to actual physical frame/page address. The logical address for a... Continue Reading →
Fenwick Trees
In this post I will talk about Fenwick Trees aka Binary Indexed Trees. I got to use them recently while solving a problem in a coding challenge. Problem: Let's say we have an array of N positive integers. We need to be able to serve the following two operations efficiently: GetPrefixSum(i) - Gets the cumulative... Continue Reading →
Loonytek - Delving into Tech 