Metadata

This is a short chapter covering the nuts and bolts of memory allocation in C: malloc(), free(), and the many ways programmers get them wrong. This is part of our series going through OSTEP book chapters. The OSTEP textbook is freely available at Remzi's website if you like to follow along. Stack vs. Heap C gives you two kinds of memory. Stack memory  is automatic: the compiler allocates it when you enter a function and reclaims it when you return. Heap memory  is manual: you allocate it with malloc()  and free it with free() . Let's remember the layout from Chapter 13. The distinction is simple in principle: use the stack for short-lived local data, use the heap for anything that must outlive the current function call. The heap is where the trouble lives. It forces the programmer to reason about object lifetimes at every allocation site. The compiler won't save you; a C program with memory bugs compiles and runs just fine, until it doesn't. The API malloc(size_t siz...

This paper (Sigmod 2013) gives an overview of the design of the Hekaton engine which is optimized for memory resident data and OLTP workloads and is fully integrated into Microsoft SQL Server. The paper starts with a strongly opinionated paragraph: SQL Server and other major database management systems were designed assuming that main memory is expensive and data resides on disk. This assumption is no longer valid; over the last 30 years memory prices have dropped by a factor of 10 every 5 years. Today, one can buy a server with 32 cores and 1TB of memory for about $50K and both core counts and memory sizes are still increasing. The majority of OLTP databases fit entirely in 1TB and even the largest OLTP databases can keep the active working set in memory. I really like this paper. The paper is self-contained and is easy to follow. It is very well written. It has the old-school touch: it is succinct and opinionated, it explains principles/tenets behind design, and it does not oversell...