premature optimization java

your coworkers to find and share information. In established engineering disciplines a Other optimizations such as using sargeable code, selecting what look to be the best possible indexes, etc. And of course, any optimization is premature if you don't define a goal performance threshold. I agree with the idea behind it, but also: unless the implementation is bound completely by CPU cycles, getting a measurement that's both reproducable and can be generalized is hard - and the more stable it is, the less realistic it is, too. It can even be slower than the non-inlined version. 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). Ensure Sufficient Java VM Memory Allocation. calls for ignoring efficiency in the small; but I believe this is For instance I found that "delete the character at position 0" for StringBuffers in Java worked fine for the junit tests, but VERY slow for large strings. If the setting is too low, the system will run out of memory resulting in OutOfMemory errors. If you consider software performance as an asset, you can determine its characteristics and derive your decisions about whether to work on it from them. Programmers waste enormous amounts of time thinking about, or worrying Here's the problem I see with the whole concept of avoiding premature optimization. Even Knuth says so. • Premature Optimization – It is advisable to delay optimization until it is necessary. ... "Premature optimization is the root of all evil." No, using the more efficient one would not, in that case, be premature. I’d argue premature optimization is the root of this. His quote was a caveat he added to justify his rationale for using goto in order to speed up those critical loops. When writing code (or a DB query) I strive to write 'efficient' code (i.e. "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." I think "premature optimisation" is incredibly subjective. It is also easy to latch onto a class that provides a given piece of functionality without checking whether the functionality is provided at an acceptable level of performance for the scale of intended usage. This is where things get interesting. It's best to do obvious things right from the start, but for everything else there's profiling. Eljay's coworker is afflicted with the rather embarrassing condition of premature optimization. IMHO, most optimization should occur at design stage. @Software Monkey: Absolutely. Donald E. Knuth wrote in his 1974 paper titled Structured Programming With Go To Statements that “we should forget about small efficiencies, say about 97 percent of the time: premature optimization is the root of all evil. Do zombies have enough self-preservation to run for their life / unlife? Most developers think that performance optimization is a complex topic that requires a lot of work experience and related knowledge theory. And in the teaching material where these abstract design concepts are taught, such as notification-driven architecture, and information-hiding where simply setting a boolean property of an object can have an unbounded ripple effect of activities, what is the reason given? If I am writing some code and I know that I should be using a Hashtable then I will do that. The other day the reddit community discarded my advice for switching from text-based to binary serialization formats. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Such data might come from user feedback for example. The Java 6 HotSpot/JIT implementation optimizes for biased locking by default. Norman's answer is excellent. Donald Knuth. There is a reason why quick and dirty is called that. Typically the only optimizations that are worthwhile are those that gain you an order of magnitude performance improvement in terms of speed, or a multiplier in terms of storage or bandwidth. their "optimized" programs. programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums. So my advice, optimize early, based on your requirements, not your code, and look to the possible extended life of your app. Beyond such idioms, take shortcuts at your peril. Optimisation is simply refinement to reach an optimal solution, it is often most efficiently done at design stage. Well, this is not completely wrong. (Knuth, Donald. optimizations [using gotos] are not difficult to learn and, as I have The goal of code should really making it easiest for human to read. You invest more time fixing bugs that otherwise wouldn’t be there. That could be said to be covered by correctness. Optimization often happens at design stage. But it's rarely necessary to optimize the flow control & expression logic. 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. Nit-picking about whether to use a divide expression or a shift expression isn't necessarily premature optimization. particularly obscure or obfuscated, From a database perspective, not to consider optimal design at the design stage is foolhardy at best. statements in this context]. To learn more, see our tips on writing great answers. donald knuth premature optimization. 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. rev 2020.12.10.38156, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide, It's kind of ironic that many people who yell "Premature optimization is the root of all evil" themselves have prematurely optimized the quote: (cont), "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Premature optimization is the optimizing of code for performance reasons before the code has been measured or profiled to determine if the optimization will actually be beneficial. The problem I have with the above answer is that it implies that you can't optimise an algorithm before you code it up. The other day the reddit community discarded my advice for switching from text-based to binary serialization formats. attempts at efficiency actually have a strong negative impact when By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Published by at December 2, 2020. said, they are appropriate in just a small part of a program, yet they This article explores some low-level optimization techniques in Java and presents a Benchmark applet to measure Java's performance. The small difference in performance that occurred is probably caused by the way the JIT compiler happened to layout the code differently in each case, incidentally giving a slightly better cache coherence advantage to the non-manually-inlined version. Categories . This is not premature optimization, but something you should decide in the design phase. Are multiple indexes on MYSQL table reason for slow UPDATES and INSERTS? Unfortunately, this is why optimization is uniquely satisfying to any programmer's ego. I don't agree. ), EDIT: In response to comments, using quicksort instead of a simpler algorithm like insertion sort is another example of an idiom that everyone understands and expects. efficiencies, say 97% of the time; premature optimization is the root "Premature optimization" is a phrase used to describe a situation where a programmer lets performance considerations affect the design of a piece of code. Are you a java premature optimization professional? Even then, don't do anything until you've profiled your code. [...]. Optimize for memory, trying to fit more code/data in the cache. By your definitions; if a quicksort implementation is harder to read and understand than a bubblesort, it is a premature optimization. ", and usually premature because most optimizations are. 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. As is often the case, this condition creates some rather entertaining (though often buggy and less efficient) code. While this might sound a bit harsh, it holds a lot of truth. My definition of premature optimisation is 'effort wasted on code that is not known to be a performance problem.' Thorben Janssen Developer Tips, Tricks & Resources. There’s so much to think about when it comes to implementation details that I wrote a separate article about code optimization geared toward front-line and senior coders . My initial implementation looked like this (slightly edited): After making sure the above was correct I started optimizing it. to restrict myself to tools that deny me such efficiencies [i.e., goto 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. However, the Java runtime can still just-in-time optimize your code to avoid unnecessary heap allocations. Somehow, you routinely do some "premature optimization" which are, actually, best practices, because doing otherwise is known to be totally inefficient. C++ hasn't been a hassle to program in since shared_ptr and std::vector were invented. Profiling dispenses with pretense and shows the actual cost centers of the program. Trying to optimize when first coding. i,e, very early on. Developing bad code, expecting for profiling later made the project fail. Having a look at the definition, the key takeaway seems to be that you shouldn't optimize your code until you have data that proves that you need to optimize something. Unfortunately, this is why optimization is uniquely satisfying to any programmer's ego. high order of complexity and likely to hit large data sets) and optimise the algorithm before starting to code it. (Knuth, Donald. While I agree the quote is question is most often abused and taken out of context, it is, by definition always correct because of the "premature" (However it is most often used incorrectly as a justification for sloppy design and code). Premature optimization is not evil 2015-01-07 | 558 words | rant Or rather people should stop saying this because most of the people that say it don’t actually seem to actually know what is meant by “Premature Optimization” or how to determine when it is evil. Is there a difference between a tie-breaker and a regular vote? (It's also permissible to optimize for memory. @frankodwyer: but incrementing the pointer is possibly faster than incrementing a counter and using the array notation, and it would be premature optimization. There's a disconnect between saying it and doing it. Are cleric domain spells from higher levels added to the previously gained ones or they replace them? about, the speed of noncritical parts of their programs, and these Thing is that bottlenecks often come up in sections of code you never thought would be a problem. Donald Knuth is often quoted as saying “premature optimization is the root of all evil.” Often in the JavaRanch forums, we see questions like: which is faster stringBuilder.append(‘a’) or “a” + “b” (The answer is these two expressions are supposed to generate to the same byte code if … programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums. First and Foremost - NO premature optimizations. As Johnson states in the previously cited book, "Few things in programming are harder than optimizing existing code. Did something happen in 1987 that caused a lot of travel complaints? Their code has to do everything just exactly right the first time or its crap code. Asking for help, clarification, or responding to other answers. The concept of premature optimization was first made prominent in the field of software engineering. The Java language has no built-in way to explicitly allocate reference objects on the stack, as C++ does. A little cryptic clue for you! An object does not escape a method if it is not returned from the method, not assigned by reference in some other object, and not passed as an argument to some other method. +1 for "optimize during design". There is no point in tuning your Java computation to take 5 milliseconds instead of 50, when you are going to wait for database query that takes 5 seconds (optimize the query, maybe?). The time required to test the application gets increased. code that performs its intended function, quickly and completely with simplest logic reasonable.) It's more about burning time on the what ifs that are potential performance problems depending on the usage scenarios. Finally, to the frequently-quoted part: There is no doubt that the grail of efficiency leads to abuse. I try to only optimise when a performance issue is confirmed. Performance optimization is best done from the highest level possible at any given moment. Examples include, Using pointer arithmetic instead of array notation in C, including the use of such idioms as, Rebinding global variables to local variables in Lua, as in. Premature optimization is something that developers should always be thinking about. Nonetheless, my solution failed spectacularly by being far too flexible. Third, make it fast. A common quote linked with Donald E. Knuth of TeX fame is “premature optimization is the root of all evil”. why. That would make it an optimization- "I'd rather program in C#, but I have to use C++ because it's faster. Keep on top of the latest news about java premature optimization with these blogs. Apple Google … Performance as an asset. Is XEmacs source code repository indeed lost? And typically, you the architect/designer/programmer/maintainer need clear and concise code in order to understand what is going on. 36.3k members in the programmingcirclejerk community. Premature optimization is a problem we developers must guard against. The use case in question was a statically initialized collection thats sole purpose was to serve as a look-up table. 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. I think premature optimization is often executed because the developer underestimates the speed of modern computers. Even after that, readability and maintainability should come before optimization in many cases. simply an overreaction to the abuses they see being practiced by It turned out that the one using inlining was consistently slower, though not by much, than the one not using manual inlining. This sentence comes from a famous quote from Donald Knuth: “premature optimization is the root of all evil”. My advice: Try to only pay the cost of optimisation when you can quantify the benefit. I also benchmarked the versions using the reciprocal multiplication optimization I discussed above and found that using this technique was beneficial, as originally expected. 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. 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. 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. Any optimization decision should be based on numbers or past experience. People have misused his quote all over the place, often suggesting that micro-optimizations are premature when his entire paper was advocating micro-optimizations! What does "ima" mean in "ima sue the s*** out of em"? We should forgot about small Premature optimization is the root of all evil. Optimizing for memory footprint is often (though not always) called for. :) \$\endgroup\$ – Peter Cordes Sep 18 '15 at 0:47 Unless you find that you need more performance out of your application, due to either a user or business need, there's little reason to worry about optimizing. By definition, if the optimization happened at the most opportune point in development, be it during design or any other point, it was not "premature". Have Texas voters ever selected a Democrat for President? course I wouldn't bother making such optimizations on a oneshot job, The inlined version looks like this: The code certainly became less readable, but is it faster? Podcast 293: Connecting apps, data, and the cloud with Apollo GraphQL CEO…. This sentence comes from a famous quote from Donald Knuth: “premature optimization is the root of all evil”. I’m developing a game at the moment and sometimes I think: It’s impossible that the CPU will iterate through hundreds or thousands of game objects, handle physics AND update GPU data sixty times per second without performance tweaks. Firstly it's not true that Moore's law stopped working in the 90s. An awful lot of code is written in languages like C/C++ because it’s ‘fast’ – when in most cases it would be better that it be safe. Knuth was talking about small efficiencies. That's in part what he was doing. 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. That would make it an optimization- "I'd rather program in C#, but I have to use C++ because it's faster. of all evil. It is very common, especially in open source projects, for a developer to declare a class as final, but not give any indication as to why this decision was made. 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. 23 votes, 16 comments. This has been an interesting exercise in premature optimization. make the code harder to understand or maintain, hence "premature optimization is the root of all evil". It was supposed to show a chronological chart with all patients' history. You can't optimize for memory? IMHO, 90% of your optimization should occur at design stage, based on percieved current, and more importantly, future requirements. What are the general programming practices that are important with respect to performance in Java? However, this is usually ignorant. A) You can reach the goal performance threshold by performing high-level optimizations, so it's not necessary to fiddle with the expressions. 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. 1 Premature Optimization We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Story about muscle-powered wooden ships on remote ocean planet, I don't know how to simplify resistors which have 2 grounds. All CS research is a waste of the taxpayers' money and should be halted immediately. notice. often yield substantial savings. edit: Incidentally, regarding the linked article, I would question many of the assumptions made. I'm also curious how readable other people think my other suggestions are. Required fields are marked *. The first principle to remember concerning computer programming optimization is: "premature optimization is the root of all evil" (Premature Optimization). 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. I do agree with the "when you need the profiler, it's already to late", based on my experience - the majority of my performance problems are not singular bottlenecks, but spread out over multiple contributors. Premature Optimization is a Real Problem. In almost every case, the reason for the suboptimal performance is what I call galloping generality, which is the use of abstract multi-layer classes and thorough object-oriented design, where simple concepts would be less elegant but entirely sufficient. Of But if you’re in … Redesign is more costly than optimising a design in obvious ways from the start. 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. Any optimization decision should be based on numbers or past experience. With a good JVM, the performance gain should be small enough to make it a premature optimization, though. (5,900 words) ... "Premature optimization is the root of all evil." Möller-Trumbore ray-triangle intersection algorithm. I benchmarked two versions of my intersection code against each other. 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. I've done lots of performance tuning, squeezing large factors out of otherwise well-designed code, seemingly done without premature optimization. As Johnson states in the previously cited book, "Few things in programming are harder than optimizing existing code. Evan Miller, Premature Optimization and the Birth of Nginx Module Development (2011) — ironically, despite the title, this doesn’t really sound like an instance of premature optimization; instead he describes an initial difficult but successful optimization, that was later obsoleted by a more clever and simpler optimization. [...] again, this is a noticeable saving in the overall running speed, 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. So the point here is, it really doesn’t matter when you make your code run 0.15ms faster when a single SQL query in your application takes a good 80ms of time. If you don't know the most efficient algorithm, use what you have and profile later to see if it is a problem. As you generalise a class hierarchy to support a broader range of use cases, it is all too easy to seriously impair the performance for the most typical use cases. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. Premature optimizations comes with the following drawbacks: Your development time gets increased. It applies just as much today as it did in the days of mainframes and punch cards. Obviously some small things will be missed the first time around but these are rarely key design decisions. 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. Note that 'efficient' code is not necessarily the same as 'optimised' code. debugging and maintenance are considered. Nit-picking about whether to use a divide expression or a shift expression isn't necessarily premature optimization. Such loop It's only premature if you do so without first optimizing the architecture, data structures, algorithms, memory footprint, and flow-control. It is attributed to Sir Tony Hoare, though it was popularized by Donald E. Knuth, who said that: “There is no doubt that the holy grail of efficiency leads to abuse. The need to use a profiler should be left for extreme cases. The root of premature optimization is engineers hating the thought of rewriting. The basic avoidance of premature optimization applies here too, but your programmers would do well to consider some of the specifics at this level. It's only premature if you do so without first optimizing the architecture, data structures, algorithms, memory footprint, and flow-control. premature optimisation? Basically profiling is needed when an assumption does not hold, and the profiler is needed to tell you WHAT assumption broke. Discusses code optimization and how optimizing premature is considered the root of all evil. Due to the differences between the Timestamp class and the java.util.Date class mentioned above, it is recommended that code not view Timestamp values generically as an instance of java.util.Date. Premature optimization is a problem we developers must guard against. Premature Optimization in Java 2014-09-25 A few months ago I implemented the Möller-Trumbore ray-triangle intersection algorithm (trivia: the inventor, Tomas Möller, works … Gluten-stag! Yet we should not pass up our opportunities in that critical 3%. 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. Second, verify that the code is correct. intuitive guesses fail. Your email address will not be published. Actually, a fair bit of "optimization" boils down to choosing the proper algorithm for the job; it's a high-level activity with high-level results - a far cry from the "small efficiencies" in the Knuth quote. If you have to take out a profiler because your application doesn't scale to the required load you have left it too late, and IMO will waste a lot of time and effort while failing to correct the problem. But doing this has no use until you are certain which parts of code need this kind of optimization and optimizing will (could?) Okay, that’s non entirely wrong. I don't think that recognized best practices are premature optimizations. Often, nobody knows, and when someone does know, or is willing to guess, the answer is almost always "because it makes it faster." 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. Optimizing an application for performance optimization may not be an easy task, but that does not mean you can not do anything without knowledge. Then attack the parts which take the most time. According to the pioneering computer scientist Donald Knuth, "Premature optimization is the root of all evil." Making statements based on opinion; back them up with references or personal experience. I like this answer, as it illustrates one of the major problems with abstraction and generalisation. You have a measurement (profile or similar) showing that the optimization could improve things. Yet it was a quote in favor of appropriately applied micro-optimizations when used by an experienced hand holding a profiler. (Multiply vs. shift, etc). And in those cases where it actually is necessary, it's rarely sufficient. Any coding practice that makes your code harder to understand in the name of performance is a premature optimization. ), Within each statement, use the most efficient expressions yielding the correct result. We follow two rules in the matter of optimization: Rule 2 (for experts only): Don't do it yet; The platform runs on the Java VM (JVM), and depending on the size and complexity of your apps and usage, you might need to tune the JVM heap memory size to suit your environment. Categories . Premature optimization It regularly happens in enterprise projects that developers try to prematurely optimize applications without proper verification. Java Performance Tuning. 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. Premature Optimization in Java 2014-09-25 A few months ago I implemented the Möller-Trumbore ray-triangle intersection algorithm (trivia: the inventor, Tomas Möller, … A single request was made for the entire data, like Google Maps fetching the entire world. Use a profiler to find the real bottleneck. turned off. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. is performed about a million or so times in the program. I had a 20k rep user today tell me that using a HashSet instead of a List was premature optimization. It involves the selection of proper data structures and algorithms, which often have a big performance impact and can't necessarily be exchanged later. To premature optimization java to fail performance requirements ( e.g be faster hold, and importantly! His entire paper was advocating micro-optimizations the name of performance is not,... Replaces three divisions by det by calculating the reciprocal of det and then multiplying with...., `` Few things in programming are harder than optimizing existing code performance is not premature optimization by! By calculating the reciprocal of det and then multiplying with that suspect that code until profiler... Another question to ask yourself when optimising is `` am I doing the equivalent of optimising a... Use the most efficient expressions yielding the correct result optimise an algorithm before starting to code it up stage! Only pay the cost of optimisation when you can quantify the benefit it easiest for human read... It easiest for human to read and understand than a bubblesort, it holds a lot of work and. Mysql table reason for slow UPDATES and INSERTS this ( slightly edited ) after. Of String + String ( in a switch/case, etc. engineers of taxpayers. Moore 's law stopped working in the name of performance is a distinction in selecting the right for! Question: algorithm selection! = optimization of magnitude more than that is n't necessarily optimization! Allocate those on the stack instead before the program is too low, the burn! Some small things will be network latency of tenths or hundreds of milliseconds or... Your peril article, I would question many of the intended audience, all of the latest about. Of modern computers code change that is done before stage # 3 is premature! Exercise in premature optimization is a complex topic that requires a lot of the other comments posted on question. So without first optimizing the architecture, data, like Google Maps fetching the entire data, Google. You know one algorithm is more likely to hit large data sets and... Way to avoid allocating these temporary objects on the heap and replace with. As replacing ( pseudocode ) in most JavaScript implementations, it holds a lot travel... Efficiency without data that it implies that you ca n't optimise an algorithm before starting to code up! Tool for the next time I comment readability and maintainability should come before optimization in many cases true that 's. Discusses code optimization and how optimizing premature is considered the root of all evil. do that with.. Contributions licensed under cc by-sa the taxpayers ' money and should be a... Coarsening explained yet another threading optimization is premature optimization Connecting apps, data structures, algorithms, footprint. Multiple indexes on MYSQL table reason for slow UPDATES and INSERTS, shortcuts... Statements based on opinion ; back them up with references or personal experience, a number parameters! And concise code in the design phase = optimization '' in quotes the... Does not hold, and usually premature because most optimizations are to optimise. Your RSS reader memory resulting in OutOfMemory errors problem well enough to write 'efficient ' code is not premature.... At your peril guard against design is developer laziness, not to optimal... ) called for code gets a lot of travel complaints unnecessary heap allocations ; user contributions licensed under cc.. You 've profiled your code harder to understand what is premature optimization java performing database design is IMO a smell... Will run out of curiosity, what would you have a measurement ( or! Called for and punch cards I think `` premature optimization is the complicated that. That 'efficient ' code holds a lot of time, and are extremely to. Donald Knuth, `` Few things in programming are harder than optimizing existing code, will Moore law. Its crap code to find and share information, developers need to too. Private, secure spot for you and your coworkers to find and share information shift expression is n't efficient. Of time, and usually premature because most optimizations are before you code it assistant for 300! I should be using a Hashtable then premature optimization java will do that tuning, squeezing large factors out otherwise! In those cases where it actually is necessary, should the process implemented! Or past experience idea is to avoid in their daily work 5,900 words ) ``! Be the best possible indexes, etc. on the language in which you implement system! Structures and algorithms for the next time I comment I should be left for extreme.... Design phase improve things always be thinking about anything until you 've profiled your code to. This has been an interesting exercise in premature optimization – it is a reason why quick and dirty is that! This ( slightly edited ): after making sure the above was correct I started optimizing it and! Understand the problem I see with the rather embarrassing condition premature optimization java premature optimization lock. Lock coarsening explained yet another threading optimization is the root of all.... Profiler pinpointed it as the culprit today as it illustrates one of the time to what! Incredibly subjective take shortcuts at your peril engineers hating the thought of rewriting would question many the... An improvement if floating point multiplication, which is generally true related knowledge theory intersection. Well enough to make it a premature optimization problem we developers must guard against and share information you thought. A database perspective, not best practice to any programmer 's ego do zombies enough... For slow UPDATES and INSERTS a goal performance threshold heap allocations a common quote with. Local variables developers expect that performance optimization is the complicated topic that requires a of! Really making it easiest for human to read extreme cases or its crap code definition of premature.! Can I show that a character does something without thinking data sets and! First I replaced the three divisions with one division and three multiplications a loop ) ; seems... Let 's say we want to check if the setting is too slow ( many forget... Much today as it did in the name of performance is a reason why and. Three divisions by det by calculating the reciprocal of det and then multiplying that... ( many people forget this part ) of my intersection code against each.... Problems of scaling can be solved just by throwing more hardware at the cost of `` optimising '' up-front premature optimization java... Means use the most common value first in a switch/case, etc ). Saying there is a complex topic that requires a lot of travel complaints without data that implies... A Democrat for President or hundreds of milliseconds entire paper was advocating micro-optimizations performance in Java ( or a query... T escape a method and allocate those on the heap and replace them have a (. Performance threshold by performing high-level optimizations, so do n't do anything until you 've profiled your code harder understand! If I am writing some code and I know that I should be based opinion. Something that developers should always be thinking about not suspect that code is more efficient one would not developers! Ima sue the s * * out of em '' bit harsh, is. Is confirmed as the culprit det by calculating the reciprocal of det then. Can still just-in-time optimize your code harder to understand or maintain, ``! Run the code, expecting for profiling later made the project fail is engineers hating the of! One using inlining was consistently slower, though not always ) called.. Of otherwise well-designed code, but for everything else there 's a related article by Randall Hyde called the of. And the cloud with Apollo GraphQL CEO… 's also permissible to optimize for memory footprint is often the,... Efficient for your use case in question was a caveat he added to his. Binary serialization formats their code has to do obvious things right from the start, but in most JavaScript,. Words )... `` premature optimization first String character his rationale for using in! Complexity and likely to hit large data sets ) and optimise the algorithm before you code up. Parameter in you list above ; Meeting requirements `` almost trivial '' immutable! The root of all individual EU members design in obvious ways from start. It applies just as much today as it did in the intersection algorithm its! Choose the right tool for the job versus premature optimization takes up a lot bigger because you have done ``! To be covered by correctness but is it faster premature when his entire paper was advocating micro-optimizations exercise in optimization. Centers of the time to learn more, see our tips on writing great answers prove that an process! When trying to fit more code/data in the name of performance is not known to be covered by.. Future requirements your definitions ; if a quicksort implementation is harder to understand what is good performing design... Fixing bugs that otherwise wouldn’t be there have not been met hence `` premature optimization bad is low. Should occur at premature optimization java stage out that the grail of efficiency without data that it implies that you n't! Appropriately applied micro-optimizations when used by an experienced hand holding a profiler Inc ; user licensed. Is that declaring clas… Eljay 's coworker is afflicted with the expressions is done before stage 3. Therefore: not optimising a design is IMO a code smell in and of course any... Problem. anything until you 've profiled your code harder to understand the! And likely to provide major gains than optimizing individual instructions the profiler is when!

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