After following, you can keep track of his dynamic information in a timely manner
The core difference between OLTP and OLAP lies in its purpose and design goals. 1.OLTP is used for daily transaction processing, emphasizing high concurrency, fast response and small data operations, and is suitable for bank transfers, e-commerce ordering and other scenarios; 2.OLAP is used for data analysis and decision-making support, and handles complex queries and big data aggregation, which is suitable for sales trend analysis, customer behavior research and other scenarios; 3. There are significant differences in the data structure, update frequency and response time of the two. When choosing, it should be decided based on business needs. OLTP is used for high-frequency transactions, and OLAP is used for in-depth analysis.
Jul 31, 2025 am 09:26 AM
Quantum computing uses qubits to process information, and the Qiskit library can help understand and practice its basic concepts. First install Qiskit: enter pipinstallqiskit on the command line; it is recommended to use JupyterNotebook for development. Then create the first quantum circuit: initialize the circuit, add Hadamard gate to achieve superposition state, measure the results and run the simulator; the output results will show about 0 and 1 of about 50% each. Qiskit provides a variety of emulators, such as statevector_simulator and qasm_simulator; real quantum devices can also be used through IBM Quantum Experience, but you need to register an account and get it.
Jul 31, 2025 am 09:24 AM
ACPU'sperformancedependsoncores,clockspeed,andthreads;foroptimalchoice,prioritizebasedonusage:1.Forgamingandsingle-taskspeed,higherclockspeedand6–8coresareideal.2.Forvideoediting,3Dmodeling,orstreaming,prioritize8 coresand16 threads.3.Foreverydaytask
Jul 31, 2025 am 09:23 AM
Yes,youcanwriteawebscraperinGofromscratchusingthestandardlibraryandgolang.org/x/net/html;2.First,usenet/httptofetchthepageandio.ReadAlltoreadthebody;3.ParsetheHTMLwithgolang.org/x/net/html.Parsebycreatingareaderfromthebody;4.TraversetheDOMtreerecursi
Jul 31, 2025 am 09:23 AM
The key to handling date-time functions and time zone conversion in SQL is to unify the storage format and clarify the conversion logic. 1. Different databases have different functions that obtain the current time, and the server time zone time is returned by default. It is recommended to use functions with time zone control such as NOW()ATTIMEZONE. 2. It is recommended to store UTC time and convert it to user time zone when displayed, and use the TIMESTAMPWITHTIMEZONE type and ATTIMEZONE function to convert it. 3. Time zone conversion should rely on the database or language library's time zone database, avoid manually adding and decreasing the number of hours, use standard time zone names to support daylight saving time, and check the database default time zone settings to ensure accuracy.
Jul 31, 2025 am 09:23 AM
The future development trends of Java include: 1. The release model centered on the LTS version, and enterprises will mainly adopt long-term support versions such as Java17 and Java21; 2. ProjectLoom introduces virtual threads to greatly improve concurrency performance and simplify the programming model; 3. Enhance cloud-native and microservice support through GraalVM, Quarkus and other technologies to reduce resource consumption; 4. Continue to introduce modern language features such as record classes, pattern matching, sealing classes, etc. to improve expression and security; 5. Although JVM languages such as Kotlin and Scala have risen in specific fields, Java still maintains the dominant position of enterprise development with its ecological advantages; overall, Java is maintaining its enterprise-level and post-end through continuous evolution.
Jul 31, 2025 am 09:21 AM
The core basis for the MySQL query optimizer to select indexes is the cost-based cost model (CBO), which determines the optimal solution by evaluating the cost of different execution paths. 1. The optimizer will consider factors such as scanning row count, reading page count, whether to return to table, whether to use sorting or temporary tables. 2. Common reasons for the unselected index include: uneven data distribution or inaccurate statistical information, resulting in incorrect cardinality estimation; the cost of backing the table is too high, and the optimizer believes that full table scanning is more efficient; query writing makes the index invalid, such as using functions, leading fuzzy matching, or some of the no index in the OR condition. 3. It is recommended to run ANALYZETABLE regularly, avoid indexing in low-dividing fields, create coverage indexes to reduce back to tables, write SQL reasonably and use EXPLAIN analysis.
Jul 31, 2025 am 09:21 AM
This article introduces how to implement CNN in Python. First, you need to install necessary libraries such as TensorFlow/Keras or PyTorch, as well as numpy and matplotlib related to data processing. Then use Keras to build a simple CNN model, including a convolutional layer, a pooling layer and a fully connected layer, and compile and train it through compile and fit methods. Then, the CNN writing method in PyTorch is introduced, and the network structure is built by defining classes, and the training loop is manually written. Finally, the importance of data preprocessing is emphasized, including normalization, data augmentation, and batch loading. Mastering these infrastructures, data processing and training processes can create effective CNN models
Jul 31, 2025 am 09:20 AM
Use IntersectionObserver API to efficiently implement lazy loading, which is better performance than traditional methods; 2. Set data-src to mark image placeholding, and use the observer to monitor elements to load real resources when entering the viewport; 3. It can be expanded to lazy load components, advertisements or comments to reduce the load on the first screen; 4. Preload critical content with rootMargin to improve user experience; 5. Animation triggers are also applicable, and the elements are played when they are visible to avoid scrolling lags; 6. Pay attention to avoid monitoring too many elements, and call unobserve() in time to release resources; 7. Polyfill is required for unsupported old browsers. This API allows the browser to automatically handle visibility detection, significantly
Jul 31, 2025 am 09:20 AM
To master CSSGrid, first use display:grid to create a grid container, and use grid-template-columns/rows to define row and column sizes, supporting fr, auto and fixed values; 2. Use gap to set grid spacing to avoid using margin; 3. Use grid-column/row or grid-area to accurately place projects, and use grid-template-areas named areas to improve readability; 4. Use repeat(auto-fit, minmax(250px, 1fr)) to achieve responsive column adaptation; 5. Master justify-content/align-co
Jul 31, 2025 am 09:14 AM
Implementing the JWT-based RESTAPI security mechanism in SpringBoot applications, first of all, you need to understand that the server issues the JWT after the user logs in, the client carries the token in the Authorization header of subsequent requests, and the server verifies the validity of the token through a custom filter; 2. Add spring-boot-starter-security, spring-boot-starter-web and jjwt-api, jjwt-impl, and jjwt-jackson dependencies in pom.xml; 3. Create a JwtUtil tool class to generate, parse and verify JWT, including extracting usernames, expiration time, generating tokens and proofing
Jul 31, 2025 am 09:13 AM
Choosetherightcomputeservice—useGKEformicroservices,CloudRunforstatelessapps,orAppEngineforsimplicity,andautomatedeploymentswithCloudBuild.2.LeveragemanagedserviceslikeCloudSQL,Firestore,Pub/Sub,andCloudStoragetoreduceoperationaloverheadandensureinde
Jul 31, 2025 am 09:11 AM
Angularisbestforlarge-scaleenterpriseapplicationsrequiringstructureandbuilt-intools,2.Reactexcelsindynamic,high-performanceUIswithmaximumflexibilityandavastecosystem,3.Vueoffersabalanced,beginner-friendlyapproachidealforstartupsandincrementaladoption
Jul 31, 2025 am 09:11 AM
Raceconditionsoccurwhenmultiplethreadsaccessshareddata,leadingtoinconsistencies;fixwithsynchronized,AtomicInteger,orReentrantLock.2.Deadlockariseswhenthreadswaitindefinitelyforeachother’slocks;preventbyconsistentlockordering,usingtryLockwithtimeout,a
Jul 31, 2025 am 09:09 AM
java.lang.OutOfMemoryError: Javaheapspace indicates insufficient heap memory, and needs to check the processing of large objects, memory leaks and heap settings, and locate and optimize the code through the heap dump analysis tool; 2. Metaspace errors are common in dynamic class generation or hot deployment due to excessive class metadata, and MaxMetaspaceSize should be restricted and class loading should be optimized; 3. Unabletocreatenewnativethread due to exhausting system thread resources, it is necessary to check the number of threads, use thread pools, and adjust the stack size; 4. GCoverheadlimitexceeded means that GC is frequent but has less recycling, and GC logs should be analyzed and optimized.
Jul 31, 2025 am 09:07 AM
MySQL's JSON data types provide powerful functions, not only storing structured and semi-structured data, but also support verification, query and modification. First, it automatically verifies the JSON format to ensure data integrity; secondly, it can efficiently query data through functions such as JSON_EXTRACT() and support generating column indexes to improve performance; finally, using functions such as JSON_SET() to accurately update part of the data to avoid rewriting the entire document. Rationally utilizing these tools can effectively process JSON data in a production environment.
Jul 31, 2025 am 09:06 AM
Go language can efficiently implement common data structures through built-in types and generics: 1. Use map[T]struct{} to implement Set, save memory and support generics, suitable for deduplication and permission checking; 2. The stack is implemented with slice, and Push/Pop is completed using append and slice operations, which is suitable for LIFO scenarios such as expression evaluation; 3. The queue can be implemented with slice or container/list. The former is simple but the Dequeue is O(n), and the latter is more efficient based on bidirectional linked lists, which is widely used in BFS and message buffering; 4. The heap is built with priority queues by implementing container/heap.Interface, which is often used in TopK and scheduling algorithms; 5. Concurrency security
Jul 31, 2025 am 09:05 AM
Thecontent-visibilityCSSpropertyisn’tjustavisualrenderingtool—it’sapowerfulperformanceoptimizationfeaturethatcansignificantlyimprovepageloadtimesandruntimeefficiency,especiallyforlongorcomplexpages.Byenablingthebrowser
Jul 31, 2025 am 09:05 AM
Install the appropriate JDK (recommended Java17LTS version, use trusted distributions such as EclipseTemurin), set JAVA_HOME and PATH environment variables, and pass java-version and javac-version verification; 2. Select a professional IDE (recommended IntelliJIDEACommunity), configure the compiler, code style and necessary plug-ins such as Lombok and SonarLint; 3. Use the build tools Maven or Gradle to manage dependencies and project structures, it is recommended to use GradleWrapper or install Maven and configure MAVEN_HOME; 4. Install Git and configure user information
Jul 31, 2025 am 09:01 AM
UsetheAWSLambdaGoruntimewithlambda.Start()toefficientlyhandletheinvocationlifecycleandcompileforLinuxusingGOOS=linuxGOARCH=amd64.2.Minimizepackagesizebyremovingunuseddependencieswithgomodtidy,strippingdebuginfovia-ldflags="-s-w",andavoiding
Jul 31, 2025 am 08:58 AM
To write efficient and reusable SQL stored procedures, four key points must be followed: 1. Modular design, split common logic such as data verification and permission judgment into independent stored procedures or functions, such as CheckUserAccess, to improve reusability and maintainability; 2. Use parameterized input instead of hard coding, such as implementing dynamic queries through @status parameters, enhance flexibility and reduce the risk of SQL injection; 3. Make good use of temporary tables and table variables to optimize complex logic, table variables are suitable for small data volumes, temporary tables are suitable for large data volumes and support indexes, improving execution efficiency and readability; 4. Pay attention to indexes and execution plans, check whether indexes are effectively used to avoid full table scanning, handle parameter sniffing problems, and ensure efficient and stable process operation.
Jul 31, 2025 am 08:57 AM
Installing Nginx on Ubuntu/Debian requires updating the package list (sudoaptupdate), installing Nginx (sudoaptinstallnginx-y), starting and enabling services (sudosystemctlstart/enablenginx); 2. On CentOS/RHEL, you need to enable EPEL source (sudodnfinstallepel-release-y), installing Nginx, starting services, and opening the firewall HTTP/HTTPS port (firewall-cmd command); 3. After installation, you should verify the configuration syntax (sudonginx-t) and check the default site directory.
Jul 31, 2025 am 08:50 AM
XGBoost is an efficient implementation of GradientBoosting, suitable for the classification and regression tasks of structured data. 1) Install and use pipinstallxgboost and import the module; 2) When preparing data, you can directly use Pandas or Numpy input, or convert it to DMatrix to improve efficiency; 3) The training model can be constructed by XGBRegressor or XGBClassifier class; 4) It is recommended to adjust parameters and adjust the parameter combinations such as n_estimators, learning_rate, max_depth, subsample, etc. in turn, and use GridSearchCV to automatically search for the optimal configuration; 5) Pay attention to setting
Jul 31, 2025 am 08:47 AM
Ifyouneedportabilityandworkinmultiplelocations,choosealaptop;ifyouprioritizemaximumperformanceatafixedlocation,chooseadesktop.2.Desktopsoffersuperiorupgradabilityandlongevity,allowingcomponentreplacementstoextendlifespan,whilelaptopsaretypicallylimit
Jul 31, 2025 am 08:47 AM
ToimproveMySQLperformanceforread-heavyworkloads,followthesesteps:1.Usetherightindexingstrategybyaddingindexesonfrequentlyqueriedcolumns,especiallyinWHEREclausesandJOINconditions,whileavoidingover-indexingandconsideringcompositeindexesformulti-columnq
Jul 31, 2025 am 08:44 AM
The order should be from the most specific to the most general, avoiding conditional coverage; 2. Avoid excessively long elseif chains, and more than 8 should be replaced by mapping tables or policy patterns; 3. Ensure that conditions are mutually exclusive and include else to handle unexpected situations; 4. Improve readability, use clear conditions and short logical blocks; 5. Write tests for each branch to cover boundaries and outliers; the key to using elseifladder correctly is to sort reasonably, keep simplicity, handle edge cases, improve maintainability, and refactor them in time when complex, so as to ensure that the code is clear, safe and easy to modify.
Jul 31, 2025 am 08:30 AM
PolymorphismcanreplaceconditionallogicinOOPtoimprovecodemaintainabilityandextensibility;2.Replacetypecheckswithinheritanceandmethodoverridingtoeliminateif-elsechains,asshownbymovingfly()behaviorintosubclasseslikeEagle,Penguin,andSparrow;3.UsetheStrat
Jul 31, 2025 am 08:30 AM
CentOS7 upgrades can be achieved in three main ways: migration to CentOSStream, switching to other RHEL derivative distributions, or taking temporary support extension measures. First, upgrading to CentOSStream is the official recommended path. The steps include backing up data, installing the centos-release-stream package, executing yumdistro-sync upgrades and restarting the verification version, which is suitable for users who want to continue using the CentOS ecosystem. Secondly, alternative distributions such as RockyLinux, AlmaLinux and OracleLinux provide a similar experience to CentOS. Migration can be used to restore configuration using official scripts or reinstall the system, which is suitable for C
Jul 31, 2025 am 08:26 AM
CustombuildtagsinGoallowconditionalcompilationoffilesbasedonuser-definedconditions;tousethemeffectively:1)Definetagslike//go:buildenterpriseatthetopoffilestocontrolinclusion;2)Usegobuild-tagsenterprisetoenablespecifictags;3)Applytagsforfeatureflags,e
Jul 31, 2025 am 08:25 AM
Goworkspacesandreplacedirectivesalloweffectivemulti-moduledevelopment,withworkspacesbeingthepreferredmethodforlocaldevelopmentacrossmultiplemodules.1.Usego.worktoincludemultiplemodulesviagoworkuse,enablingautomaticlocalresolutionwithoutexplicitreplac
Jul 31, 2025 am 08:11 AM
