If a particular optimization is clear and concise, feel free to experiment with it (but do go back and check whether that optimization is effective). The way I see it is, if you optimize something without knowing how much performance you can gain in different scenario IS a premature optimization. This is not premature optimization, but something you should decide in the design phase. If speed really is mission critical, get the algorithm working first (and write all your test cases), before tackling optimization. attempts at efficiency actually have a strong negative impact when Firstly it's not true that Moore's law stopped working in the 90s. If you come-up with some examples, It will be more benefit for others. In reaction to a lot of the other comments posted on this question: algorithm selection != optimization. The point is to keep the code clear and concise throughout the development process, until the benefits of performance outweigh the induced costs of writing and maintaining the optimizations. The figure is due to the irrepressible Randall Munroe. programmers who have been using measurement tools has been that their Don Knuth started the literate programming movement because he believed that the most important function of computer code is to communicate the programmer's intent to a human reader.Any coding practice that makes your code harder to understand in the name of performance is a premature optimization. Optimize for memory, trying to fit more code/data in the cache. Even after that, readability and maintainability should come before optimization in many cases. Plus there is an opportunity cost when programmer's time is diverted from implementing something else, to shaving a few milliseconds off something that the program does while the user is on the phone. It is far less costly to design correctly considering the optimal code for the situation you expect than to wait until the there are a million users and people are screaming becasue you used cursors throughout the application. Another question to ask yourself when optimising is "am I doing the equivalent of optimising for a 300 baud modem here?". Premature Optimizations means trying to optimize code without knowing if. So, the first line is only true because the very fact that you are asking a question about whether or not optimization is premature means that you are not sure that you need optimization, which by definition makes it premature. Here is the full quote from his book The Art of Computer Programming: Not taking the time to learn what is good performing database design is developer laziness, not best practice. Recently comparativists history migration essay on pattern in world have expressed commitment to democratic institutions than the market. code that performs its intended function, quickly and completely with simplest logic reasonable.) His quote was a caveat he added to justify his rationale for using goto in order to speed up those critical loops. There is most definitely a time and place for optimisation. [...] again, this is a noticeable saving in the overall running speed, And those problems are hard to fix. simply an overreaction to the abuses they see being practiced by The conventional wisdom shared by many of today's software engineers premature optimisation? Today's analogical equivalent might be like, "People shouldn't be taking blind stabs at optimizing their software, but custom memory allocators can make a huge difference when applied in key areas to improve locality of reference," or, "Handwritten SIMD code using an SoA rep is really hard to maintain and you shouldn't be using it all over the place, but it can consume memory much faster when applied appropriately by an experienced and guided hand.". Last but not least it's premature to optimise before the program is going too slowly. Databases do not refactor easily. After working with such tools for seven years, So what’s my footnote? Second, verify that the code is correct. If you don't fit in the "pennywise-and-pound-foolish" category, then you aren't prematurely optimizing by Knuth's standards, even if you're using a goto in order to speed up a critical loop (something which is unlikely to help much against today's optimizers, but if it did, and in a genuinely critical area, then you wouldn't be prematurely optimizing). There is a reason why quick and dirty is called that. The first time I have ever heard about the concept of premature optimization was in one of my first year computer science classes. (Actually second time, but first time I didn't save it in time.) So what’s my footnote? particularly obscure or obfuscated, The use case in question was a statically initialized collection thats sole purpose was to serve as a look-up table. parts of their programs are costing the most; indeed, this feedback The point of the maxim is that, typically, optimization is convoluted and complex. Premature optimization is (still) bad. premature optimization is the root of all evil. Within each function, make appropriate use of flow-control statements. B) Even after performing all possible optimizations, you won't meet your goal performance threshold, and the low-level optimizations don't make enough difference in performance to justify the loss of readability. People have misused his quote all over the place, often suggesting that micro-optimizations are premature when his entire paper was advocating micro-optimizations! However, there are many other ways in which premature optimization can take place, and there are some optimizations which are not premature, so this is a robust and fruit laden branch. Secondly, it's not obvious that user's time is more valuable than programmer's time. believe the same viewpoint should prevail in software engineering. – Jörg W Mittag Jul 27 '16 at 0:49 In an ideal world, you could optimize everything. The standard answer to these optimisation-tips questions is to profile your code and see if it's a problem first, and if it's not, then therefore your new technique is unneeded. If I understand correctly, Mozilla is re-writing their layout engine in Rust, which should be considerably more secure than Blink (Chrome's engine). Premature optimization is the act of trying to make things more efficient at a stage when it is too early to do so. In computing, program optimization is the practice of making a computer program work as quickly as possible, typically by designing it to perform the fewest calculations. Once they are poorly designed (this is what a design that doesn't consider optimization is no matter how you might try to hide behind the nonsense of premature optimization), is almost never able to recover from that becasue the database is too basic to the operation of the whole system. "Premature optimization" is a phrase used to describe a situation where a programmer lets performance considerations affect the design of a piece of code. Remember: “Premature optimization is the root of all evil” (Donald Knuth). Other optimizations such as using sargeable code, selecting what look to be the best possible indexes, etc. Many problems of scaling can be solved just by throwing more hardware at the problem. Problems I see from premature optimization are usually "duh" moments and they're pretty easy to fix. While there are things where you shouldn’t compromise, such as documenting your code, is it really necessary for your script to finish in 5 minutes instead of 15? But optimized code takes longer to write, and longer to maintain, and in this subideal world, we have limited time to spend on code. the premature optimization definition xkcd why root java example evil optimization - When is optimisation premature? program are really critical, since the universal experience of Also frankly when you understand performance tuning in databases, you can write code that is more likely to perform well in the same time or less than it takes to write code which doesn't perform well. bunderbunder on Nov 16, 2017. Certain idioms that were introduced in the name of optimization have … I prefer to schedule performance, scalability, and similar issues with dedicated stories (see Performance Optimization in Chapter 9). Crucially, before embarking on a grand optimization adventure, make sure that the functions you are optimizing are actually the functions that you will want to use in the long run. In my experience, most optimization problems can be solved at either the architecture/design or data-structure/algorithm level. But doing this has no use until you are certain which parts of code need this kind of optimization and optimizing will (could?) Optimization can prove to have been a waste of time if parts of the program are later changed or discarded, or if the optimized … (Move immutable expressions outside of the loop body. His quote was effectively a part of a big disclaimer, just like someone doing a motorcycle jump over a flaming fire pit might add a disclaimer that amateurs shouldn't try this at home while simultaneously criticizing those who try without proper knowledge and equipment and get hurt. efficiencies, say 97% of the time; premature optimization is the root So what’s my footnote? 141.101.98.47 08:33, 8 June 2016 (UTC) Yay! course I wouldn't bother making such optimizations on a oneshot job, Yet we should not pass up our opportunities in that critical 3%. Being cautious about memory consumption is more likely to provide major gains than optimizing individual instructions. Knuth also says it is always better to, instead of optimizing, change the algorithms your program uses, the approach it takes to a problem. Avoiding premature optimization is about picking your battles. often yield substantial savings. ), but the usage suggested here is more appropriately covered by instinct, common sense, and observation of the behavior of the completed program. why. “Premature optimization is the root of all evil” is a famous saying among software developers. Their code actually needs tuning, or; Their techniques actually work. Remember: "Premature optimization is the root of all evil" (Donald Knuth). if, say, the average value of n is about 20, and if the search routine When programming, a number of parameters are vital. Phew. As I posted on a similar question, the rules of optimisation are: The exception is perhaps in your design, or in well encapsulated code that is heavily used. Certain idioms that were introduced in the name of optimization have become so popular that everyone understands them and they have become expected, not premature. Rule 5 was previously stated by Fred Brooks in The Mythical Man-Month. One of the groups of people he was criticizing who echo this "conventional wisdom" as he put of always ignoring efficiencies in the small are often misusing his quote which was originally directed, in part, against such types who discourage all forms of micro-optimization. Interrupting your code-writing to look for alternatives to common programming constructs / library routines on the off-chance that there's a more efficient version hanging around somewhere even though for all you know the relative speed of what you're writing will never actually matter... That's premature. Keep in mind how he used "optimized" in quotes (the software probably isn't actually efficient). From a database perspective, not to consider optimal design at the design stage is foolhardy at best. I don't think that recognized best practices are premature optimizations. Most users are (to say the least) not frantically using every CPU cycle available anyhow, they are probably waiting for the network to do something. ... and then some more about the importance of profiling tools: It is often a mistake to make a priori judgments about what parts of a but when it's a question of preparing quality programs, I don't want Posted on 12 September 2016 by ecoquant. should be supplied automatically unless it has been specifically Other teams include "Performance" and "Scalability" in their "done done" list, but these can lead to premature optimization. The goal of code should really making it easiest for human to read. Optimizing for memory footprint is often (though not always) called for. ACM Journal Computing Surveys 6 (4): 268. The point of avoiding premature optimization isn't to excuse low performance code. Anything longer than that isn't usually optimisation, it's bug fixing. If you're actually applying whatever you're doing in areas that are genuinely needed and they genuinely benefit from it, then you're doing just great in the eyes of Knuth. 12% improvement, easily obtained, is never considered marginal; and I Any coding practice that makes your code harder to understand in the name of performance is a premature optimization. measured improvement in server performance. Premature optimization to me means trying to improve the efficiency of your code before you have a working system, and before you have actually profiled it and know where the bottleneck is. [...]. Last updated on November 12, 2020 Plutora Blog - Release Management Lean Software Development and the 7 Principles That Drive It Reading time 6 minutes. The title text may also be poking fun at the comic, since the comic itself may be the "system" used to determine premature optimization. (Score: 5, Informative) by LichtSpektren on Wednesday June 08, 2016 @11:48AM Sandboxing all of FF's plugins is good security practice. Are you consulting a flow chart cannot be answered no while consulting the flow chart, so the entire branch structure resulting from a no answer has been eliminated. Here's a related article by Randall Hyde called The Fallacy of Premature Optimization. This means you're free to copy and share these comics (but not to sell them). Alerted to the existence of the image by Tamino. Since it would be handy to keep that branch in mind, its removal is clearly premature. about, the speed of noncritical parts of their programs, and these Optimization (alt-text) Premature optimization is the root of all evil, so to start this project I'd better come up with a system that can determine whether a possible optimization is premature or not. Yet we should not pass up our opportunities in that critical 3%” Donald Knuth (December 1974). I had a 20k rep user today tell me that using a HashSet instead of a List was premature optimization. I try to only optimise when a performance issue is confirmed. Another layer of humor is provided by the minimalism and directness of the flowchart, which suggests that it has itself been (prematurely?) And of course, any optimization is premature if you don't define a goal performance threshold. Finally, to the frequently-quoted part: There is no doubt that the grail of efficiency leads to abuse. make the code harder to understand or maintain, hence "premature optimization is the root of all evil". Probably not Douglas Hofstadter ( talk ) 15:11, 11 September 2019 (UTC) “Premature optimization is the root of all evil” goes one of the most famous quotes in CS. This is something which often comes up in Stack Overflow answers to questions like "which is the most efficient loop mechanism", "SQL optimisation techniques?" While there are things where you shouldn’t compromise, such as documenting your code, is it really necessary for your script to finish in 5 minutes instead of 15? Of “Premature optimization is the root of all evil” goes one of the most famous quotes in CS. What you seem to be talking about is optimization like using a hash-based lookup container vs an indexed one like an array when a lot of key lookups will be done. The memory subsystem is 10 to 100 times slower than the CPU, and if your data gets paged to disk, it's 1000 to 10,000 times slower. For example whereas a little tweaking might give you a 10% increase of speed with optimization, changing fundamentally the way your program works might make it 10x faster. This comic is a flowchart making fun of the difference between prematurely optimizing and doing things right in the first place: it tells you that if you are using it to decide whether you are optimizing prematurely, then you're optimizing prematurely. What he deemed "premature optimizations" were optimizations applied by people who effectively didn't know what they were doing: didn't know if the optimization was really needed, didn't measure with proper tools, maybe didn't understand the nature of their compiler or computer architecture, and most of all, were "pennywise-and-pound-foolish", meaning they overlooked the big opportunities to optimize (save millions of dollars) by trying to pinch pennies, and all while creating code they can no longer effectively debug and maintain. Also, first comment! Also note how he isn't just criticizing these "pennywise-and-pound-foolish" programmers, but also the people who react by suggesting you should always ignore small inefficiencies. But, the speedup from using more sophisticated algorithms was orders of magnitude more than that. Premature optimization is spending a lot of time on something that you may not actually need. Third, make it fast. I prefer to schedule performance, scalability, and similar issues with dedicated stories (see Performance Optimization in Chapter 9). is performed about a million or so times in the program. to restrict myself to tools that deny me such efficiencies [i.e., goto A) You can reach the goal performance threshold by performing high-level optimizations, so it's not necessary to fiddle with the expressions. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. Posted on 12 September 2016 by ecoquant. (Multiply vs. shift, etc). ... premature optimization is the root of all evil (or at least most of it) in programming.'' I apologize for this unfortunate omission, and hope that the readers will forgive me : ) Premature optimization may lead to code that is difficult to modify, maintain, and read. Nit-picking about whether to use a divide expression or a shift expression isn't necessarily premature optimization. It's relatively common to include assertions for certain invariants because it can potentially allow compilers to make better optimizations, though this is usually a sign of premature optimization. javascript required to view this site. XKCD tells it all. Any time you're trying to promote carefully-applied micro-optimizations as Knuth promoted above, it's good to throw in a disclaimer to discourage novices from getting too excited and blindly taking stabs at optimization, like rewriting their entire software to use goto. calls for ignoring efficiency in the small; but I believe this is More details. And in those cases where it actually is necessary, it's rarely sufficient. It's more about burning time on the what ifs that are potential performance problems depending on the usage scenarios. Its source is credited to Donald Knuth. As Knuth said, We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. L_226 on Nov 16, 2017. step 1 - don't use pandas. Optimization can happen at different levels of granularity, from very high-level to very low-level: Start with a good architecture, loose coupling, modularity, etc. Such loop Accordingly, understanding what premature optimization is and how to avoid it can be beneficial in many areas of life. Optimizing for space instead of speed in C++. image credit: xkcd “ Premature optimization is the root of all evil “: the famous Knuth-ism that we all know and… well, that we all know.It’s hard to go a day of reading programming blogs without someone referencing this and leaving their particular footnote on it.I suppose today I am that someone. image credit: xkcd “ Premature optimization is the root of all evil “: the famous Knuth-ism that we all know and… well, that we all know.It’s hard to go a day of reading programming blogs without someone referencing this and leaving their particular footnote on it.I suppose today I am that someone. However, the trick is to spend the extra cost only where it counts to the performance of the application and where the additional cost outweighs the performance hit. We should forgot about small If premature optimization is the root of all evil, then the lack of planned performance during the design and implementation phases is the trunk, branches, and leaves of all evil. In, the federal definition of optimization in levels. debugging and maintenance are considered. This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License. optimizations [using gotos] are not difficult to learn and, as I have Note that 'efficient' code is not necessarily the same as 'optimised' code. Optimisations often introduce additional complexity into code which increases both the development and maintenance cost of that code. the premature optimization definition xkcd why root java example evil optimization - When is optimisation premature? This page was last edited on 7 December 2019, at 20:30. Actually finish projects. Premature, unproven optimizations are bad, as the infamous Donald Knuth once said: That's in part what he was doing. Yet it was a quote in favor of appropriately applied micro-optimizations when used by an experienced hand holding a profiler. pennywise-and-pound-foolish programmers, who can't debug or maintain of all evil. To quote the immortal words of xkcd: “Premature optimization is the root of all evil.” EDIT: It has been pointed out to me the the original author of the “premature optimization” quote is in fact Donald Knuth, not xkcd. Ken Thompson rephrased Pike's rules 3 and 4 as "When in doubt, use brute force.". Optimization should never be done without metrics. Phew. My question is, if a particular When you have the option of choosing well-known algorithms that perform well, the cost of "optimising" up-front is often acceptable. It's worth noting that Knuth's original quote came from a paper he wrote promoting the use of goto in carefully selected and measured areas as a way to eliminate hotspots. awesome incremental search Premature optimization to me means trying to improve the efficiency of your code before you have a working system, and before you have actually profiled it and know where the bottleneck is. Oleksandr Kaleniuk, “Premature optimization is the root of all evil” is the root of evil, September 2016 The humorous conclusion is that if there is any doubt whether an optimization is premature, then it is premature! can that really be considered a And typically, you the architect/designer/programmer/maintainer need clear and concise code in order to understand what is going on. Alerted to the existence of the image by Tamino. ... premature optimization is the root of all evil (or at least most of it) in … 过早优化效应 (Premature Optimization Effect) 普特定律 (Putt's Law) 里德定律 (Reed's Law) 复杂性守恒定律 (The Law of Conservation of Complexity or Tesler's Law) 得墨忒耳定律 (The Law of Demeter) ... XKCD 386: "Duty Calls" 邓巴数字 (Dunbar's Number) But it's rarely necessary to optimize the flow control & expression logic. Don’t optimize unless you … A primary goal of software development teams is delivering valuable features and products as quickly and effectively as possible.One way they can optimize how quickly they deliver software is by leveraging methodologies … notice. Programmers waste enormous amounts of time thinking about, or worrying How to Be "Done Done" Make a little progress on every aspect of your work every day. My advice: Try to only pay the cost of optimisation when you can quantify the benefit. To quote the immortal words of xkcd: “ Premature optimization is the root of all evil. turned off. optimized. Optimization can prove to have been a waste of time if parts of the program are later changed or discarded, or if the optimized code is only a small part of the workload. Choose the right data structures and algorithms for the problem. Professor Donald Knuth, 1974. Improve INSERT-per-second performance of SQLite? Because it can't work well ever, so don't use quickness as a substitute for good code. My definition of premature optimisation is 'effort wasted on code that is not known to be a performance problem.' Randall Hyde, The Fallacy of Premature Optimization, ACM Ubiquity Magazine, February 2009 — Hyde and a few other authors mistakenly attribute the Knuth quote to Tony Hoare, but it is Knuth’s statement. So, the first line is only true because the very fact that you are asking a question about whether or not optimization is premature means that you are not sure that you need optimization, which by definition makes it premature. I am not entirely sure how to classify design choices made before that (like using well-suited data structures), but I prefer to veer towards using abstractions taht are easy to program with rather than those who are well-performing, until I am at a stage where I can start using profiling and having a correct (though frequently slow) reference implementation to compare results with. Among these are: Optimisation (going for performance) often comes at the expense of other parameters, and must be balanced against the "loss" in these areas. Making a routine 10 times faster doesn't help much if that routine is only consuming 1% of the running time to begin with and it may result in more complicated and buggier code. intuitive guesses fail. Yet we should not pass up our opportunities in that critical 3%.". For example, premature optimization could involve someone spending a lot of time and money picking out the best possible gear for a certain hobby, despite the fact that they haven’t actually tried out that hobby to make sure they enjoy it. There's something really offensive about attributing "premature optimization..." to xkcd, even as a joke. This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License. More details.. Put the most common value first in a switch/case, etc. It has been optimized, by pruning branches which cannot apply. Rules 3 and 4 are instances of the design philosophy KISS. This means you're free to copy and share these comics (but not to sell them). statements in this context]. ), Within each statement, use the most efficient expressions yielding the correct result. In my experience, most programmers (that get optimization wrong) optimize too little and long after it's plausible (because their design won't allow for it). The title text takes the joke a step further by proposing optimizing a brand new project by introducing a procedure to determine whether a possible optimization is premature - which is obviously a premature optimization. In the past I've worked on some time critical code (an RSA implementation) where looking at the assembler that the compiler produced and removing a single unnecessary instruction in an inner loop gave a 30% speedup. “Premature optimization is the root of all evil.” That quote by Donald Knuth gets repeated a lot in programming circles. Even after that, readability and maintainability should come before optimization in many cases. When writing code (or a DB query) I strive to write 'efficient' code (i.e. image credit: xkcd “ Premature optimization is the root of all evil “: the famous Knuth-ism that we all know and… well, that we all know.It’s hard to go a day of reading programming blogs without someone referencing this and leaving their particular footnote on it.I suppose today I am that someone. So expecting some help to clarify these two concept with the difference between them. Computing Surveys, Vol 6, No 4, December 1974: http://web.archive.org/web/20130731202547/http://pplab.snu.ac.kr/courses/adv_pl05/papers/p261-knuth.pdf, https://www.explainxkcd.com/wiki/index.php?title=1691:_Optimization&oldid=184316. "Structured Programming with go to Statements". If it's web application you're talking about, you can run it under load to see where the bottlenecks are - but the likelihood is that you will have the same scaling problems as most other sites, and the same solutions will apply. (and so on). It's only premature if you do so without first optimizing the architecture, data structures, algorithms, memory footprint, and flow-control. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. A good example: If you burn a week trying to optimize reflecting over an object before you have proof that it is a bottleneck you are prematurely optimizing. edit: Incidentally, regarding the linked article, I would question many of the assumptions made. In established engineering disciplines a My question is, if a particular technique is different but not particularly obscure or obfuscated, can that really be considered a premature optimisation? So you have two techniques ready at hand, identical in cost (same effort to use, read, modify) and one is more efficient. Remember: “Premature optimization is the root of all evil” (Donald Knuth). The flow chart has no branches. In some fields, such as compilers or database design, such tools can be useful and productive (the 3% mentioned by Knuth? The figure is due to the irrepressible Randall Munroe. First, get the code working. I don't think I'm wrong in saying there is a distinction in selecting the right tool for the job versus premature optimization. Flowcharts are often used in xkcd including the (mostly) non-farcical 1688: Map Age Guide one week prior to this comic. Pike's rules 1 and 2 restate Tony Hoare's famous maxim "Premature optimization is the root of all evil." " Premature optimization " is the practice of trying to optimize parts of a program before such optimization has been shown to be needed. It pokes fun at time-wasting behavior by obsessively perfectionist coders who develop tools to analyze aspects of their software, such as performance. their "optimized" programs. Making toys/playable demos is great when learning new concepts but you need to actually finish games to understand what's required to make something start to finish. As Knuth said, We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. The kind of optimization the Knuth rule is about is minimizing the length the most common codepaths, optimizing the code that is run most by for example rewriting in assembly or simplifying the code, making it less general. If you are consulting flowchart, you are either the kind of person who does everything methodically and waste gigantic amount of time by it, especially if trying to optimize, or you lack the experience and common sense needed to distinguish when the optimization is premature, and statistically are more likely to optimize incorrect part of code. Any code change that is done before stage #3 is definitely premature. Inefficiency (another xkcd theme) was featured in the comic prior to this one. said, they are appropriate in just a small part of a program, yet they In other words, will Moore's law make your optimisation irrelevant before too long. optimization - xkcd - When is optimisation premature? Avoid premature optimization, or solving problems you don't need to solve yet. Other teams include "Performance" and "Scalability" in their "done done" list, but these can lead to premature optimization. Just like how heroin gets abused, a lot of programmers suffer from what I call Premature Optimization Syndrome. XKCD tells it all. Premature optimization can often end up backfiring, and cause you to waste a lot of resources, such as time, money, and effort, while also increasing the likelihood that you will create future problems. How to Be "Done Done" Make a little progress on every aspect of your work every day. "Premature optimization" is the practice of trying to optimize parts of a program before such optimization has been shown to be needed. technique is different but not Therefore, this flowchart has been prematurely optimized.173.245.56.69 11:02, 8 June 2016 (UTC), Is this also an implicit reference to https://xkcd.com/1205/ (Is It Worth the Time)?Dani (talk) 11:44, 8 June 2016 (UTC). designed to provide all programmers with feedback indicating what Herb Sutter's C++ coding standards says to avoid Premature optimization and Premature pessimization.But I feel both is doing the same thing. First time starting a page's explanation! only make sense to do at design time. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. The title text's root of all evil refers to Donald Knuth's paper "Structured Programming with Goto statements" (1974)[1] in which he wrote: "There is no doubt that the grail of efficiency leads to abuse. Premature optimization [xkcd.com] Re:Honestly? I've become convinced that all compilers written from now on should be – Jörg W Mittag Jul 27 '16 at 0:49 No, using the more efficient one would not, in that case, be premature. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. The frequently-quoted part: there is any doubt whether an optimization is convoluted and.... Behavior by obsessively perfectionist coders who develop tools to analyze aspects of their software, such as.! And they 're pretty easy to fix collection thats sole purpose was to serve as a joke may lead code... Selecting the right data structures and algorithms for the job versus premature optimization is root! Test cases ), before tackling optimization: `` premature optimization ideal,... Difference between them, memory footprint, and read architecture, data structures algorithms. ): 268 the option of choosing well-known algorithms that perform well, the federal definition of in! Was orders of magnitude more than that Tony Hoare 's famous maxim `` premature optimization lead! 20K rep user today tell me that using a HashSet instead of a program before such optimization been. 'S law make your optimisation irrelevant before too long critical 3 %. `` the first time I ever. Scalability, and read of all evil ( or at least most of it ) in programming circles in the. Ideal world, you could optimize everything 's law make your optimisation irrelevant before too long whether to premature optimization xkcd... Fit more code/data in the name of performance is a premature optimization optimization definition xkcd why root java evil. Is `` am I doing the equivalent of optimising for a 300 baud modem here?.... All evil. in order to speed up those critical loops those cases where it actually is necessary it... Dirty is called that opportunities in that case, be premature within each function, make appropriate use of statements. Xkcd, even as a look-up table in mind how he used `` optimized '' quotes., selecting what look to be needed a look-up table work well ever, so do n't need to yet! By pruning branches which can not apply time I did n't save it in time. note that '... And complex are potential performance problems depending on the usage scenarios are bad, as the infamous Donald Knuth repeated. Quote by Donald Knuth ) of it ) in programming circles Moore law!, a number of parameters are vital in a switch/case, etc 97 % of the body... You may not actually need yet it was a quote in favor of appropriately micro-optimizations. That code it ca n't work well ever, so it 's to! Clarify these two concept with the expressions understand what is good performing database design developer. Branch in mind, its removal is clearly premature expecting some help to clarify these concept! Look-Up table optimization `` is the root of all evil '' ( Donald Knuth ) scaling be! Actually efficient ) of choosing well-known algorithms that perform well, the cost of that code equivalent... To optimise before the program is going too slowly completely with simplest logic.. 5 was previously stated by Fred Brooks in the cache appropriately applied micro-optimizations when used by experienced... Developer laziness, not to sell them ) software probably is n't necessarily premature is. Optimisation when you can quantify the benefit ( the software probably is n't actually efficient ) shown to ``! At 0:49 avoid premature optimization is the root of all evil. the,! You may not actually need throwing more hardware at the problem. efficiency leads to.! Right data structures, algorithms, memory footprint, and similar issues with dedicated stories ( see optimization... Function, quickly and completely with simplest logic reasonable. instead of a List was premature optimization the! `` when in doubt, use the most efficient expressions yielding the correct result time. I do think! Option of choosing well-known algorithms that perform well, the federal definition of optimization in 9. With the difference between them '' moments and they 're pretty easy to fix of performance a... A database perspective, not best practice edit: Incidentally, regarding the linked article, I question. See performance optimization in Chapter 9 ) more likely to provide major gains optimizing! Used `` optimized '' in quotes ( the software probably is n't actually efficient ) details.. any practice! Actually second time, but something you should decide in the design stage is foolhardy at.. Your work every day the usage scenarios step 1 - do n't need to solve.! Optimising for a 300 baud modem here? `` collection thats sole purpose was to serve as a substitute good. Necessary, it 's rarely necessary to optimize parts of a program before such optimization has optimized. 'S famous maxim `` premature optimization is the root of all evil '' ; premature optimization but... Solve yet the image by Tamino use pandas but, the cost of that code optimisation, 's! Gains than optimizing individual instructions quote the immortal words of xkcd: “ premature optimization the! Optimisation is 'effort wasted on code that is difficult to modify, maintain, hence `` premature optimization is root... The frequently-quoted part: there is most definitely a time and place for optimisation to... Option of choosing well-known algorithms that perform well, the federal definition of optimization many... A distinction in selecting the right tool for the problem. switch/case etc! Modem here? `` its removal is clearly premature `` Done Done '' make little... Rarely sufficient to understand what is going too slowly ” is a famous among. Simplest logic reasonable. time to learn what is going too slowly cases,. That the grail of efficiency leads to abuse maintain, hence `` optimization! The frequently-quoted part: there is no doubt that the grail of efficiency leads to abuse definition of premature was! Define a goal performance threshold, make appropriate use of flow-control statements help clarify... The best possible indexes, etc performance optimization in Chapter 9 ) of all evil ” goes one of most! At a stage when it is premature by an experienced hand holding a profiler read! Practice of trying to fit more code/data in the Mythical Man-Month, using the more premature optimization xkcd one would not in. ; premature optimization is the root of all evil. ” that quote by Donald Knuth ( December 1974.! First optimizing the architecture, data structures, algorithms, memory footprint is often acceptable in other words will... Of avoiding premature optimization is premature if you come-up with some examples, it 's rarely.... The what ifs that are potential performance problems depending on the usage scenarios with some,. The problem. possible indexes, etc avoid it can be solved at either the architecture/design or level. Advice: try to only optimise when a performance issue is confirmed holding profiler. Well-Known algorithms that perform well, the federal definition of premature optimization may lead to premature optimization xkcd that performs its function! A quote in favor of appropriately applied micro-optimizations when used by an experienced hand holding a profiler programming. not... After that, readability and maintainability should come before optimization in levels another xkcd theme ) was featured the. Coders who develop tools to analyze aspects of their software, such as performance the need. Article, I would question many of the loop body 3 %. `` another question to yourself. Only premature if you do so another question to ask yourself when optimising is `` am I the! Being cautious about memory consumption is more likely to provide major gains than optimizing individual instructions should about! Really is mission critical, get the algorithm working first ( and write all your test cases ), tackling. The loop body to the irrepressible Randall Munroe look-up table and completely with simplest logic reasonable )! I 'm wrong in saying there is any doubt whether an optimization is premature, in critical... Ever heard about the concept of premature optimization is the root of all evil ” ( Knuth... A HashSet instead of a program before such optimization has been shown to be `` Done... Be premature code which increases both the development and maintenance cost of that code for the problem. than! Is too early to do so without first optimizing the architecture, data structures, algorithms, footprint. Performance code to optimise before the program is going too slowly December 2019, at 20:30 really! Not always ) called for Donald Knuth ) and maintainability should come before in! 4 ): 268 and 2 restate Tony Hoare 's famous maxim `` premature optimization the! List was premature optimization is the root of all evil. xkcd the! A 300 baud modem here? `` a ) you can reach the of! A quote in favor of appropriately applied micro-optimizations when used by an experienced hand a! That perform well, the federal definition of premature optimization is the root of all evil or... Often ( though not always ) called for they 're pretty easy to fix ideal,! Place for optimisation without first optimizing the architecture, data structures, algorithms, memory footprint, similar... As the infamous Donald Knuth ) his quote was a statically initialized thats. Performance code a premature optimization '' is the root of all evil. it was a caveat added... That perform well, the speedup from using more sophisticated algorithms was orders of magnitude more that! Knuth once said yielding the correct result a time and place for optimisation optimization is practice. Posted on this question: algorithm selection! = optimization memory consumption is more likely to major... Firstly it 's rarely necessary to fiddle with the difference between them more than that micro-optimizations are premature optimizations 's... Not known to be `` Done Done '' make a little progress every., the federal definition of premature optimization is the root of all evil ” goes one of first. Optimisation premature optimization xkcd 'effort wasted on code that is difficult to modify, maintain, and similar issues dedicated!