This 2021 blog post argues against prematurely optimizing code for performance, using the analogy of a free diver holding their pee to dive deeper. While holding your pee might offer a tiny perceived advantage in the short term, it's ultimately detrimental to your overall performance and can even be harmful. Similarly, micro-optimizations early in a project often add complexity, make the code harder to understand and maintain, and ultimately hinder progress toward larger, more impactful optimizations later on. Focus on writing clean, clear code first and address performance bottlenecks only when they become a proven problem, allowing for more effective and impactful optimization strategies when they are actually needed.
In a blog post titled "Pee If You Want to Go Deeper (2021)," published on May 24, 2021, on the website peeifyouwanttogofaster.com, the author, Julia Evans, delves into a detailed exploration of the process of optimizing a piece of software for enhanced performance. Specifically, the post centers around optimizing a Ruby program designed to interact with a Postgres database. Initially, the program exhibited sluggish performance, taking an unreasonably long time to execute its intended function. Through a methodical and iterative approach to optimization, Evans chronicles her journey of identifying and addressing the performance bottlenecks.
Evans begins by profiling the code, employing tools to pinpoint the precise sections consuming the most time. This initial investigation reveals that a significant portion of the program's execution time is dedicated to database interactions. Recognizing this, she embarks on a quest to optimize these interactions. She meticulously examines the SQL queries generated by the Ruby program and discovers that a substantial number of redundant queries are being executed. This redundancy stems from the program repeatedly fetching the same data from the database. To rectify this inefficiency, she introduces a caching mechanism. This cache stores the results of frequently executed queries, thereby obviating the need for repetitive database trips. The implementation of this caching strategy demonstrably reduces the execution time, marking a significant step towards optimization.
Furthermore, Evans scrutinizes the structure of the database schema itself. She observes that certain queries are inherently slow due to the absence of appropriate indexes. Indexes in a database function analogously to an index in a book, allowing for rapid retrieval of specific information. By judiciously adding indexes to relevant columns in the database tables, she further enhances the speed of data retrieval, contributing to a more responsive and performant program. Evans underscores the importance of measuring performance improvements at each stage of the optimization process. This rigorous approach ensures that each modification demonstrably contributes to a positive outcome.
Throughout the post, Evans emphasizes the iterative nature of software optimization. She highlights that achieving optimal performance is not a one-step process but rather a cycle of profiling, identifying bottlenecks, implementing solutions, and meticulously measuring the impact of those solutions. The title of the post, "Pee If You Want to Go Deeper," serves as a metaphorical representation of this iterative process. Just as a diver needs to periodically resurface for air to continue exploring the depths, a programmer must periodically step back, reassess their progress, and identify new avenues for optimization. The post concludes with the successful optimization of the Ruby program, showcasing a substantial reduction in execution time. Evans leaves the reader with the valuable lesson that consistent, measured optimization can yield significant performance gains, leading to a more efficient and responsive software application.
Summary of Comments ( 38 )
https://news.ycombinator.com/item?id=43149648
Hacker News users discuss the potential benefits and drawbacks of intentionally dehydrating for freediving, as described in the linked article. Some express skepticism about the practice, citing potential health risks and questioning the claimed performance gains. Others share anecdotes of unintentionally experiencing similar effects due to pre-dive nervousness or limited access to fluids. The validity of the "mammalian diving reflex" and its role in freediving is also debated, with some users pointing out its limitations and emphasizing the importance of proper training and safety precautions. A few commenters highlight the ethical considerations of promoting potentially dangerous practices, particularly to novice freedivers. Overall, the discussion reveals a mixed reception to the article's central premise.
The Hacker News post titled "Pee If You Want to Go Deeper (2021)" has generated a number of comments discussing the linked article about freediving and the mammalian diving reflex. Several commenters focus on the physiological aspects discussed in the article.
One commenter questions the article's assertion that holding one's breath triggers the mammalian diving reflex, stating that other stimuli, such as cold water immersion on the face, are the primary triggers. They further explain that apnea (breath-holding) itself only causes a minor peripheral vasoconstriction, a small part of the overall diving reflex. This commenter also highlights the importance of distinguishing between the diving response and the urge to urinate, suggesting they are separate but possibly coincidentally related phenomena. They also mention freediving training often involves suppressing the urge to breathe, which may coincidentally reduce the urge to urinate.
Another commenter, seemingly a freediver, offers their personal experience, noting that they rarely feel the urge to urinate during shallow dives, but the urge becomes pronounced during deeper dives, especially around 30 meters. They link this to increased pressure and diaphragmatic compression. They also mention the necessity of wearing a wetsuit for thermal protection at such depths, which may also influence urination urges by restricting bodily functions somewhat.
Another commenter points out that many mammals, including humans, possess a voluntary sphincter muscle allowing conscious control over urination, suggesting that the urge doesn't automatically result in urination. They emphasize the importance of this control for hygiene and social reasons.
Other comments touch upon related topics such as the usefulness of exhaling before a dive to reduce buoyancy and the potential risks of shallow water blackouts. One commenter questions the article's claim that divers can "access an air pocket in their stomachs" during emergencies, explaining that no such air pocket exists and that the phenomenon being referenced is likely related to changes in lung volume due to pressure differences. This commenter also mentions the dangers of "lung squeeze" at deeper depths, even while performing the valsalva maneuver to equalize pressure.
Several shorter comments express general agreement with the article's premise or offer anecdotal evidence about experiencing the urge to urinate while swimming or diving.