ACID: My Personal

I had a chance recently to chat with my old friend, Andreas Reuter, the inventor of ACID. He and his Ph.D. advisor, Theo Härder, coined the term in their famous 1983 paper, Principles of Transaction-Oriented Database Recovery. I had blinders on after almost four decades of seeing C based on my assumptions. One big lesson for me is to work hard to ALWAYS question your assumptions. Try hard to surround yourself with curious and passionate people, both young and old, who will challenge you and try to dislodge your blinders. Foster a culture that makes them safe as they do so.

Main Memory Database Recovery

Many of today’s applications need massive real-time data processing. In-memory database systems have become a good alternative for these requirements. These systems maintain the primary copy of the database in the main memory to achieve high throughput rates and low latency. However, a database in RAM is more vulnerable to failures than in traditional disk-oriented databases because of the memory volatility. DBMSs implement recovery activities (logging, checkpoint, and restart) for recovery proposes. Although the recovery component looks similar in disk- and memory-oriented systems, these systems differ dramatically in the way they implement their architectural components, such as data storage, indexing, concurrency control, query processing, durability, and recovery. This survey aims to provide a thorough review of in-memory database recovery techniques. To achieve this goal, we reviewed the main concepts of database recovery and architectural choices to implement an in-memory database system. Only then, we present the techniques to recover in-memory databases and discuss the recovery strategies of a representative sample of modern in-memory databases.

Transaction Dependency Based Approach for Database Damage Assessment Using a Matrix

One of the critical concerns in the current era is information security. Companies are sharing vast online critical data, which exposes their databases to malicious attacks. When protection techniques fail to prevent an attack, recovery is needed. Database recovery is not a straightforward procedure, since the transactions are highly interconnected. Traditional recovery techniques do not consider the interconnection between transactions because this information is not saved anywhere in the log file. Thus, they rollback all the transactions starting from the detected malicious transaction to the end of the log file. Hence, both affected and benign transactions will be rolled back, which is a waste of time. This paper presents an algorithm that works efficiently to assess the damage caused in the database by malicious transaction and recovers it. The proposed algorithm keeps track of the transactions that read from one another and store this information in a single matrix. The experimental results prove that the algorithm is faster than any other existing algorithm in this domain.