This article analyzes why the total record count returned by PageHelper mismatches the actual number of rows, examines the underlying PageInfo and PageSerializable source code, and provides a concrete solution that avoids type conversion and directly constructs PageInfo from the mapper result to ensure accurate pagination.
This article explains Elasticsearch fundamentals—including clusters, nodes, shards, replicas, segments, routing, indexing, updates, deletions, search flow, pagination methods, and visualization tools—while offering practical optimization recommendations for high‑performance and scalable deployments.
This article explains pagination rationalization in SpringBoot using MyBatis PageHelper, illustrates common unreasonable pagination scenarios, demonstrates a bug caused by page deletion, and shows how a simple two‑line configuration or per‑query setting resolves the issue while detailing the underlying implementation.
This article explains why using OFFSET and LIMIT for pagination becomes a performance bottleneck on massive tables, illustrates the cost of full‑table scans, and introduces a cursor‑based pagination technique that leverages primary‑key ordering for efficient data retrieval.
Unexpected duplicate registrations, truncated query results, and password‑reset SQL errors in a Java backend were traced to PageHelper’s ThreadLocal pagination state persisting across requests when startPage() is called without immediate query execution, so developers should ensure immediate execution or manually clear the ThreadLocal to prevent stale LIMIT clauses.
The article analyzes unexpected behaviors caused by PageHelper in a Java backend project—such as duplicate registrations, limited query results, and password update errors—by dissecting its source code, ThreadLocal usage, and the importance of proper startPage() and clearPage() handling.
This article examines the challenges of querying massive follower lists stored in MySQL, compares limit‑based pagination with tag‑record and range‑limit methods, and offers practical indexing and query‑optimization recommendations for handling tables containing hundreds of millions of rows.
This article introduces a Vue 3 GridList component that supports responsive grid layouts, server‑side pagination via a request function, and virtual scrolling to render only visible items, providing performance improvements for large data sets while offering clear usage examples and full source code.
This article explains how to create a MySQL database and table, connect to it using PHP PDO, and implement server‑side pagination with configurable page size, total‑page calculation, and navigation links, providing complete code examples for each step.
This guide walks through integrating MyBatis‑Plus with Spring Boot, covering dependency setup, configuration, entity annotations, CRUD operations, pagination, logical deletion, enum handling, automatic field filling, multi‑data‑source support, and testing with concrete code examples and detailed explanations.
When a system’s data grows, MySQL queries can become slow and cause latency; this article presents practical optimization strategies—including query tuning, pagination, join improvements, subquery replacement, order‑by and group‑by enhancements, and count() efficiency—illustrated with sample tables, code snippets, and performance screenshots.
This article recounts three production‑level pagination bugs encountered in a payment system, explains why they occurred—ranging from naive batch processing to MySQL's nondeterministic LIMIT behavior—and shows how proper pagination, ThreadLocal cleanup, and deterministic ordering resolve the issues.
This article explains why MySQL's LIMIT offset,size becomes slower as the offset grows, compares it with LIMIT size, details the internal execution using primary and secondary indexes, discusses deep pagination issues, and presents practical optimization techniques to improve query performance.
This article explains how to achieve conditional fuzzy queries and pagination in Redis by leveraging Sorted Sets and Hashes, detailing command usage, data modeling, combination strategies, and performance optimizations such as expiration and real‑time updates.
This article explains how to use Redis Sorted Sets for efficient pagination, leverages Hashes and HSCAN for multi‑condition fuzzy searches, and combines both techniques with optimization strategies such as temporary ZSet expiration and real‑time update handling to build a practical caching‑layer query solution.
This article analyzes the performance problems of LIMIT‑based pagination on massive MySQL tables and presents three progressively more efficient solutions—including a simple LIMIT approach, a tag‑record method using the last primary key, and a range‑limit method with cached min‑ID—along with best‑practice indexing recommendations to keep query latency in the tens of milliseconds even for tables containing billions of rows.
This article explains the core principles and multiple usage patterns of MyBatis PageHelper for pagination, demonstrates code examples, details its internal ThreadLocal and interceptor mechanisms, and highlights common pitfalls with safe versus unsafe practices to ensure reliable data retrieval.
The article recounts three real‑world pagination bugs—batch‑processing loops, misuse of MyBatis PageHelper, and nondeterministic results from identical ORDER BY values—explaining why they occur, how they manifest in production, and concrete fixes to avoid data loss or endless loops.
This article explains the principle of pagination and provides three reusable PHP functions—get_total_pages, get_offset, and generate_pagination—along with example code to calculate total pages, determine record offsets, and render a navigation bar for efficient web page data paging.
This article examines why combining ORDER BY with LIMIT in MySQL pagination can produce duplicate rows on subsequent pages, analyzes the optimizer’s priority‑queue behavior introduced in version 5.6, and presents practical solutions such as using unique sort keys, adding ID ordering, and understanding deep‑pagination limitations.
When a single MySQL table grows to millions of rows, offset‑based pagination becomes painfully slow, so this article explains why, measures the performance impact, and presents three practical sharding‑aware pagination strategies—including global query, jump‑page prohibition, and a two‑step query method—along with concrete SQL rewrites and optimization tips.
This article explains how to create a generic useList hook for Vue 3 that handles pagination, data fetching, filtering, resetting, exporting, and customizable success/error hooks, complete with TypeScript generics and Element‑Plus UI integration.
The article explains how large‑offset (deep) pagination in MySQL and distributed databases degrades performance and increases memory and bandwidth usage, and describes VtDriver's streaming and SQL‑rewrite techniques along with practical recommendations such as range queries and sub‑queries to mitigate these issues.
This article walks through a real‑world incident where a pagination‑related slow‑query caused massive CPU spikes, details the step‑by‑step investigation, and presents several MySQL optimization techniques—including ID‑based queries, sub‑queries, and cursor‑based pagination—that ultimately resolved the performance crisis.
This article explains how to split a massive MySQL table into smaller tables, use the MERGE engine to create a unified view, troubleshoot common errors, and implement efficient pagination across the split tables with example SQL and Java code.
This article explains how Elasticsearch pagination works with from/size, why deep paging can cause performance problems, and compares alternative techniques such as Scroll, Scroll‑Scan, Sliced Scroll, Search After, and point‑in‑time (PIT) searches for handling large result sets efficiently.
The article examines various MySQL pagination strategies—including simple LIMIT clauses, sub‑query approaches, ID‑range filtering, and temporary‑table methods—provides performance measurements on a table with millions of rows, and offers practical recommendations for reducing query latency in large datasets.
This article evaluates MyBatis-Plus (MP) for Java backend development, highlighting its convenient CRUD shortcuts, code examples, maintenance challenges, magic value pitfalls, and recommended practices such as using LambdaQueryWrapper, pagination, and avoiding overly complex SQL within MP.
This article walks through a real‑world MySQL deep‑pagination incident, detailing the timeline, root‑cause analysis, and multiple optimization techniques—including ID‑based queries, sub‑queries, and cursor pagination—that ultimately stabilized the system and eliminated slow‑SQL overload.
This article explains what JSON API is, outlines its key advantages such as compound documents, sparse fieldsets, optional features, pagination and caching, compares it with GraphQL, and illustrates its practical use through a FitBit case study, helping readers decide if it fits their API design needs.
This article explains how to use Redis Sorted Sets and Hashes to achieve pagination, fuzzy multi‑condition queries, and their combination, while also discussing performance optimizations such as expiration and update strategies for generated ZSet collections.
This article explains three MySQL pagination methods—simple LIMIT syntax, MyBatis RowBounds logical pagination, and the powerful MyBatis-PageHelper plugin—detailing their usage, configuration, code examples, and performance considerations to help Java developers efficiently handle large data sets.
This article demonstrates how to generate, insert, and query millions of rows in a MySQL 5.7 table, measures pagination performance under varying offsets and result sizes, and presents several optimization techniques—including sub‑queries, indexed look‑ups, and column selection—to dramatically reduce query latency.
This article explains how to achieve efficient pagination and multi‑condition fuzzy searches in Redis by leveraging Sorted Sets for ordered paging, Hashes with HSCAN for pattern matching, and combining both techniques with caching and expiration strategies to optimize performance.
This article details a real‑world incident of severe pagination slow queries, walks through the timeline of detection, diagnosis, and mitigation steps, and presents multiple MySQL optimization techniques—including ID‑based queries, sub‑queries, scroll queries, and join‑based solutions—to resolve deep pagination performance issues.
This article examines why MySQL LIMIT pagination becomes slower with deeper offsets on a 500,000‑row table, demonstrates the performance impact with concrete queries, and presents three optimization strategies—including using ordered primary keys, subqueries, and join‑based approaches—to reduce scan range and improve query speed.
This article explains the concept of data pagination, compares server‑side and client‑side approaches, outlines their implementation details, advantages and disadvantages, and discusses testing strategies and common issues to consider when handling large data sets in web applications.
This article explains how to implement efficient pagination and multi‑condition fuzzy queries in Redis using Sorted Sets and Hashes, outlines the underlying commands, discusses combining both techniques, and offers optimization strategies such as expiration handling to maintain cache performance.
This article explains three progressively refined approaches to caching paginated list data—directly caching whole pages, caching individual object entries after querying ID lists, and caching both ID lists and object entries—highlighting trade‑offs, implementation details, and performance considerations using Java and Redis.
This article walks through creating a 10‑million‑row MySQL table, measuring pagination performance with LIMIT, and applying practical optimizations—such as index‑based subqueries, ID‑range queries, and column selection—to dramatically reduce query latency on large data sets.
This article explains three progressively finer-grained approaches to caching paginated lists in Java—directly caching whole pages, caching individual objects after retrieving their IDs, and caching both ID lists and object entries using Redis structures—along with code examples and performance considerations.
This article explains how JD.com’s retail shopping‑cart team tackled growing business complexity by redesigning the cart with a full asynchronous architecture, detailing the overall solution, implementation challenges such as fine‑grained retries and monitoring, and the resulting performance gains.
The article details how a finance team tackled a 50‑million‑row MySQL transaction table by analyzing the pre‑split problems, defining split goals, choosing sharding‑jdbc, addressing multi‑datasource transaction and pagination issues, designing a phased migration and rollout plan, and summarizing lessons learned.
This article demonstrates how to generate, insert, and query ten‑million‑row MySQL tables, measures the latency of ordinary LIMIT pagination, analyzes the impact of offset size and result set size, and presents practical optimization techniques such as sub‑query pagination and ID‑range filtering to dramatically improve query speed.
This article walks through creating a 10‑million‑row MySQL table, measuring pagination query times under different offsets and result sizes, and presents practical optimizations such as sub‑queries, ID‑range filtering, and column selection to dramatically improve performance while explaining why using SELECT * is discouraged.
This article shows how to generate tens of millions of rows in MySQL, measure insertion and pagination performance, and apply practical optimizations such as sub‑queries for large offsets and column selection to dramatically speed up queries on huge data sets.
This tutorial shows how to use the MyBatis‑Plus‑Join (MPJ) extension to perform left‑join queries, modify mappers, build queries with MPJLambdaWrapper and MPJQueryWrapper, and add pagination, eliminating the need for manual XML SQL while improving development efficiency.
This article demonstrates how to generate millions of test rows in MySQL, analyzes the performance impact of deep pagination using LIMIT, explains why non‑clustered index lookups cause costly table scans, and presents two optimization approaches—sub‑query ID filtering and key‑set pagination—to dramatically reduce query latency.
The article explains that MyBatis PageHelper performs an extra full‑table count query causing pagination to take over eight seconds on a 10,000‑row table, analyzes the root cause, and provides a concrete solution by customizing the count SQL with a _COUNT method and optimized mapper definitions.
The article shows a straightforward Python + Selenium script, generated by ChatGPT, that logs into a website and verifies pagination, illustrated with code screenshots and brief commentary on the author’s experience finding the problem on Zhihu.
This article explores web pagination across database, backend, and frontend layers, detailing MySQL LIMIT syntax, Java pagination implementations with PageHelper and Spring Data JDBC, and UI approaches using Thymeleaf and Element UI, providing code examples and comparative insights for developers.
This tutorial walks through integrating MyBatis‑Plus into a Spring Boot project, covering dependency setup, configuration of data sources, entity annotations, service and mapper layers, pagination, logical deletion, enum handling, automatic field filling, multi‑datasource support, and testing with full code examples.
This article details a robust solution for exporting massive MySQL datasets—potentially millions of rows—to Excel by leveraging asynchronous processing with jobs or MQ, the memory‑efficient EasyExcel library, pagination, multi‑sheet handling, OSS storage, and WebSocket notifications, ensuring performance and usability.
This article recounts a real‑world MySQL pagination outage, detailing how deep‑page queries caused massive CPU spikes, the step‑by‑step investigation, and the series of SQL redesigns—including ID‑based range queries, sub‑queries, scroll queries and join‑based solutions—that finally restored stable performance.
This article examines how MySQL uses secondary indexes to find the K‑th largest value, analyzes the O(N) time complexity caused by offset pagination, explains the underlying B+‑tree double‑linked list behavior, and presents three optimization strategies—including index covering, pagination redesign, and boundary prediction—to dramatically improve performance.
This article explains how Elasticsearch handles deep pagination, compares the traditional from/size method with Scroll and Search After techniques, details their internal query and fetch phases, provides practical code examples, and offers guidance on choosing the right approach for large‑scale search workloads.
This article analyzes Elasticsearch’s three pagination methods—from/size, scroll, and search after—explaining their internal query and fetch phases, performance trade‑offs for deep paging, and provides Java implementation examples and practical recommendations.
Combining MySQL LIKE fuzzy search with pagination can push exact‑match rows to later pages, causing duplicate brand entries; this article explains the root cause, demonstrates failing queries, and presents several fixes—including adjusting page size, splitting exact and fuzzy queries, and using CHAR_LENGTH and LOCATE functions for custom ordering.
This article examines Elasticsearch's three pagination strategies—basic from/size, scroll-based deep paging, and the newer search after method—detailing their execution phases, performance implications, code examples, and practical recommendations for choosing the appropriate approach based on data volume and real‑time requirements.
This article examines Elasticsearch's deep pagination challenges and presents three practical solutions—basic from/size, scroll API, and search after—detailing their execution phases, performance trade‑offs, code examples, and guidance on when to choose each method for efficient data retrieval.
This article explains why traditional ORDER BY … LIMIT pagination becomes slow on tens of millions of rows, analyzes the underlying index scan cost, and presents two practical optimizations—delayed join using covering indexes and a bookmark‑based approach—showing how they can cut execution time to a third or even a tenth of the original.
This tutorial walks through the front‑end portion of a publishing platform series, demonstrating how to build a Vue 3 and Element‑plus UI with TailwindCSS, implement server‑side pagination via Koa, integrate Axios with proxy and interceptors, and add complete CRUD operations—including create, edit, and delete dialogs—while showcasing the essential code snippets.
This article explains how to handle massive MySQL tables by splitting a single large table into multiple smaller tables, creating a MERGE (union) table to combine them, and using the merged view to implement efficient pagination, including necessary SQL statements and troubleshooting tips.
This article provides a step‑by‑step tutorial on adding MyBatis‑Plus to a Spring Boot project, covering dependency setup, configuration, entity annotations, CRUD operations, pagination, logical deletion, enum handling, automatic field filling, multi‑datasource support, and testing with full code examples.
The article analyzes why MySQL LIMIT pagination becomes slower as the offset grows, demonstrates the performance impact with sample queries on a 500,000‑row table, and presents three optimization strategies—using ordered primary keys, subqueries, and join‑based pagination—to reduce full‑table scans and improve query speed.
This article presents a comprehensive case study of how JD.com tackled the growing load of its shopping‑cart service by introducing an asynchronous pagination mechanism for auxiliary product information, detailing the background, objectives, technical architecture, challenges, and measurable performance and cost benefits.
This article analyzes why MySQL LIMIT pagination becomes slower on large tables, demonstrates the performance impact with real query timings, explains the underlying full‑table scan behavior, and presents three practical optimization strategies—including ordered primary‑key scans, sub‑queries, and join‑based approaches—to improve query speed.
This article explains why sharding tables improves read/write speed, then compares three pagination strategies—global query, no‑skip pagination, and two‑phase query—detailing their SQL rewrites, execution steps, performance trade‑offs, and practical examples.
This article explains why well‑designed APIs are essential, covering data modeling, resource hierarchy, naming conventions, RESTful principles, CRUD operations, versioning strategies, and pagination techniques, and provides concrete examples and guidelines to help developers create robust, maintainable, and developer‑friendly APIs.
This article examines the challenges of pagination after database sharding and presents three practical solutions—global query, jump‑page prohibition, and two‑step query—detailing their implementations, trade‑offs, and performance considerations for large‑scale order services.
This article explains why using LIMIT with large offsets slows MySQL queries, analyzes the execution flow, and presents four practical optimization techniques—including subqueries, INNER JOIN, bookmark (tag‑record) method, and BETWEEN range scans—backed by real‑world performance data and code examples.
This article explains why using OFFSET and LIMIT for pagination becomes inefficient as data grows, leading to costly full table scans, and demonstrates a high‑performance cursor‑based pagination alternative that leverages indexed primary keys to retrieve pages quickly and reliably.
This article demonstrates how to integrate Elasticsearch 6.2.1 with a Spring Boot project using the high‑level REST client, covering Maven dependencies, bean configuration, index creation and deletion, various DSL queries, pagination, sorting, boosting, boolean filters, and result highlighting with complete Java code examples.
The article outlines the growing challenges of a high‑traffic shopping cart caused by numerous RPC dependencies, proposes a full asynchronous redesign—including parallel RPC calls, batch pagination, and JSF CompletableFuture usage—addresses retry, monitoring, and timeout issues, and reports a 30% latency reduction.
This article explains how to create a reusable Vue component called PageTable that encapsulates Element UI table and pagination with built-in loading handling, data fetching via a parent-provided fetchData method, and slot-based column customization.
This article explains common anomalies caused by PageHelper in MyBatis projects, such as duplicate registrations and unexpected LIMIT clauses, analyzes the underlying ThreadLocal mechanism, and provides practical guidance on correctly using startPage() and clearPage() to prevent pagination bugs.
This article examines unexpected bugs caused by PageHelper in a Java/MyBatis project—such as duplicate registrations, limited dropdown results, and password‑reset errors—traces them to ThreadLocal misuse, explains the library’s internal pagination flow, and offers practical fixes to avoid these pitfalls.
This article explains how PageHelper integrates with MyBatis, analyzes common pagination bugs such as unexpected LIMIT clauses, duplicate registrations, and password‑reset errors, and demonstrates the internal ThreadLocal handling, startPage usage, and proper cleanup to avoid thread‑local pollution.
A backend engineer shares a step‑by‑step case study of diagnosing a 20‑second batch‑score query API, then applying three optimizations—index tuning, multithreaded execution, and request‑size limiting—to bring the response time down to under 500 ms.
This tutorial walks through integrating MyBatis-Plus into a Spring Boot project, covering dependency setup, configuration, entity annotations, CRUD service and mapper usage, pagination, logical deletion, enum handling, automatic field filling, and multi‑data‑source management, complete with code examples and testing.
This guide presents 22 practical rules for designing clean, consistent RESTful APIs—including resource-oriented URLs, kebab‑case paths, camelCase parameters, proper use of HTTP verbs, versioning, pagination, field selection, CORS, security, and monitoring—to help developers avoid common pitfalls and improve API usability.
This article provides a detailed tutorial on integrating MyBatis-Plus into a Spring Boot project, covering dependency setup, configuration, entity annotations, CRUD operations, pagination, logical deletion, enum handling, automatic field filling, and multi‑datasource support, with complete code examples.
This article explains multi‑tenant concepts, compares three data isolation strategies, and provides a step‑by‑step MyBatis‑Plus implementation—including pagination interceptor configuration, code examples, testing, and ways to exclude specific SQL from tenant filtering—helping developers build scalable SaaS back‑ends.
A comprehensive guide walks you through integrating MyBatis-Plus with Spring Boot, detailing dependency setup, configuration, entity annotations, CRUD operations, pagination, logical deletion, enum mapping, automatic field filling, multi‑datasource handling, and testing, all illustrated with runnable code examples.
The article explains the performance problems of using OFFSET and LIMIT for large‑scale database pagination, demonstrates their inefficiency with full‑table scans, and presents a faster cursor‑based alternative that relies on storing the last primary key and using LIMIT instead of OFFSET.
This article introduces the mybatis-plus-join library (v1.2.4) that adds join capabilities to MyBatis‑Plus, explains how to install it, shows usage with MPJLambdaWrapper and MPJQueryWrapper—including simple, paginated, and advanced queries—while providing complete code examples and generated SQL.
This article explains the concept of feed streams, compares push and pull implementation models, discusses storage options such as MySQL, Redis SortedSet and Cassandra, and presents optimization techniques including online‑push/offline‑pull strategies, pagination methods, and deep‑paging solutions for large‑scale systems.
This article enumerates twelve typical reasons why MySQL queries become slow—such as missing or ineffective indexes, deep pagination, massive tables, excessive joins, large IN lists, dirty pages, file‑based ORDER BY, and hardware limits—and provides concrete SQL examples and step‑by‑step optimization techniques to resolve each issue.
This article presents a comprehensive analysis and multiple optimization strategies—including multithreaded ClickHouse pagination, Elasticsearch scroll‑scan, an ES‑HBase hybrid approach, and RediSearch + RedisJSON—to efficiently filter and sort up to 10 W records from a pool of tens of millions while reducing query latency and system complexity.
This article explains three MySQL pagination techniques in Java—using LIMIT clauses, MyBatis RowBounds, and the MyBatis‑PageHelper plugin—providing syntax, XML and Java code examples, execution results, and practical recommendations for efficient data retrieval in backend development.
This article explains Elasticsearch pagination mechanisms—including from/size, deep paging drawbacks, scroll, scroll‑scan, sliced scroll, search_after and point‑in‑time—detailing their inner workings, performance trade‑offs, configuration limits, and practical recommendations for handling large result sets.
The article explains how a pagination query on a 9.5‑million‑row MySQL table using a large OFFSET can take seconds, demonstrates an optimization that moves the condition into a subquery to fetch only primary keys before joining, and validates the speed gain with buffer‑pool measurements.
This article recounts a production incident caused by a MySQL query with a huge OFFSET, explains why large offsets lead to full‑table scans and severe latency, and presents three practical solutions—including index‑covering subqueries, start‑position redefinition, and offset throttling—along with data‑generation scripts and performance test results.
This article demonstrates how a MySQL pagination query on a 9.5‑million‑row table that originally took over 16 seconds can be accelerated to under 0.4 seconds by moving the LIMIT condition into a subquery that selects only primary‑key IDs and then joining to retrieve the remaining columns, with detailed code and experimental verification.
This article explains how to perform MySQL pagination manually in a Java backend using MyBatis by calculating offset and limit, adding total‑count queries, and exposing a REST endpoint that returns paged data and total records without relying on the PageHelper plugin.
This guide presents a comprehensive set of MySQL optimization techniques—including proper use of EXPLAIN, limiting IN clause size, avoiding SELECT *, using LIMIT 1, minimizing sorting, replacing OR with UNION ALL, preferring UNION ALL over UNION, eliminating ORDER BY RAND(), distinguishing IN versus EXISTS, applying efficient pagination, segmenting large scans, avoiding NULL checks and leading wildcards, rewriting expressions, preventing implicit type conversion, respecting composite index leftmost rules, forcing indexes, handling range queries, and optimizing JOINs—to dramatically improve query performance.
This article walks through generating a 10‑million‑row MySQL table, inserting data with a fast batch script, measuring plain LIMIT pagination performance, and applying several optimization techniques—including sub‑queries, ID‑range filtering, and column selection—to dramatically reduce query time on large data sets.
The article explains why using LIMIT together with ORDER BY in MySQL 5.6 can cause duplicate records on subsequent pages, analyzes the priority‑queue optimization that makes the sort unstable, and offers practical solutions such as indexing, proper pagination logic, and query adjustments.
The article explains why large‑offset LIMIT queries on a MySQL table with millions of rows are slow, demonstrates how rewriting the query to use a subquery that first selects primary‑key IDs dramatically reduces execution time, and validates the improvement by measuring buffer‑pool page usage.
This article demonstrates how to generate, insert, and query ten‑million‑row MySQL tables, measures pagination query times under different offsets and limits, and presents practical optimization techniques such as sub‑queries, id‑range filtering, and column selection to improve performance on massive data sets.
