--- title: "Andrei Pechkurov (@puzpuzpuz) | Hashnode" description: "Top data race and segfault producer in the room. Read the latest articles by Andrei Pechkurov on Hashnode." url: "https://hashnode.com/@puzpuzpuz" --- @puzpuzpuz # Andrei Pechkurov @puzpuzpuz · Joined December 2021 Top data race and segfault producer in the room. ### [Multithreaded Execution Model for Queries With ORDER BY and LIMIT Clauses](https://puzpuzpuz.dev/multithreaded-execution-model-for-queries-with-order-by-and-limit-clauses?utm_source=hashnode&utm_medium=feed) This small post continues the previous post dedicated to multithreaded query execution in databases with column-oriented storage format. This time we'll consider queries like the following: SELECT SearchPhrase FROM hits WHERE SearchPhrase IS NOT NULL... 2 min read · [puzpuzpuz.dev](https://puzpuzpuz.dev/multithreaded-execution-model-for-queries-with-order-by-and-limit-clauses?utm_source=hashnode&utm_medium=feed) [Jun 9, 2024](https://hashnode.com/posts/multithreaded-execution-model-for-queries-with-order-by-and-limit-clauses/6665736b8d29735d83325c61) ### [An mmap-based hash table optimization](https://puzpuzpuz.dev/an-mmap-based-hash-table-optimization?utm_source=hashnode&utm_medium=feed) mmap is a controversial topic among the database community. But it does a decent job for an analytical database and unlocks some optimizations. 2 min read · [puzpuzpuz.dev](https://puzpuzpuz.dev/an-mmap-based-hash-table-optimization?utm_source=hashnode&utm_medium=feed) [Jun 1, 2024](https://hashnode.com/posts/an-mmap-based-hash-table-optimization/665aeb7226bb742d794b044a) ### [Seqlock-Based Atomic Memory Snapshots](https://puzpuzpuz.dev/seqlock-based-atomic-memory-snapshots?utm_source=hashnode&utm_medium=feed) We discuss seqlock-based atomic snapshots as an alternative to the k-word CAS algorithm when writes are infrequent and single-writer limitation is fine. 5 min read · [puzpuzpuz.dev](https://puzpuzpuz.dev/seqlock-based-atomic-memory-snapshots?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/seqlock-based-atomic-memory-snapshots/64cf7f8a79ecbf244f51df0b) [Aug 6, 2023](https://hashnode.com/posts/seqlock-based-atomic-memory-snapshots/64cf7f8a79ecbf244f51df0b) ### [A Few Thoughts on K-Word CAS](https://puzpuzpuz.dev/a-few-thoughts-on-k-word-cas?utm_source=hashnode&utm_medium=feed) A few months ago I went through Efficient Multi-word Compare and Swap paper, so here are a few thoughts on the algorithm. 2 min read · [puzpuzpuz.dev](https://puzpuzpuz.dev/a-few-thoughts-on-k-word-cas?utm_source=hashnode&utm_medium=feed) [Jul 6, 2023](https://hashnode.com/posts/a-few-thoughts-on-k-word-cas/64a6fe0c3033105b3ed48dca) ### [The Secret Life of fsync](https://puzpuzpuz.dev/the-secret-life-of-fsync?utm_source=hashnode&utm_medium=feed) What kind of durability guarantees fsync system call provides in Linux? Let's find out. 4 min read · [puzpuzpuz.dev](https://puzpuzpuz.dev/the-secret-life-of-fsync?utm_source=hashnode&utm_medium=feed) [Mar 31, 2023](https://hashnode.com/posts/the-secret-life-of-fsync/64272b39a9a93eeb27f1aeee)