1 views collected around this technical thread.
The article explains why using a VARCHAR(20) column to store billions of phone numbers is safer and more flexible than INT or BIGINT, covering range limits, data integrity, query convenience, interview expectations, and common pitfalls such as insufficient field length, charset issues, missing indexes, and lack of encryption.
The article examines an interview question about storing 2 billion phone numbers, explains why int cannot hold 11‑digit numbers, advocates using VARCHAR(20) for flexibility and data integrity, and outlines common pitfalls and best practices for database design.
When designing a schema for two‑billion phone numbers, use a VARCHAR(20) column with utf8mb4 Unicode, a unique index, and proper validation/encryption rather than a 32‑bit INT, because strings preserve leading zeros, international prefixes, extensions, and support business extensibility, fault tolerance, and future changes.
This article introduces several relatively obscure yet practical ES6 features—including Object.entries/Object.fromEntries, Symbol, WeakMap/WeakSet, Promise.allSettled, BigInt, Array.of/Array.from, and the .at and flat methods—explaining their purpose and providing code examples for each.
This article evaluates how MySQL stores time using datetime, timestamp, and bigint fields by inserting 500,000 records and measuring query, grouping, and sorting speeds, concluding that bigint generally offers the best performance for time‑range operations while timestamp saves space when no manipulation is needed.
This article evaluates how MySQL handles time data stored as datetime, timestamp, and bigint by inserting half a million records and measuring query, grouping, and sorting speeds, concluding that bigint generally offers the best performance for time‑range operations.
This article explains MySQL AUTO_INCREMENT behavior, demonstrates creating tables with unsigned int primary keys, shows how to set and inspect the AUTO_INCREMENT value, discusses its maximum limits, and recommends using bigint or explicit primary keys to avoid overflow and duplicate‑key errors.
This article explains how MySQL integer auto‑increment primary keys can reach their maximum value, the resulting duplicate‑key errors, and how using BIGINT or understanding InnoDB's internal row_id behavior can prevent data loss or crashes.
This article reviews the most useful ES2020 (ES11) JavaScript features—including private class fields, Promise.allSettled, the BigInt type, nullish coalescing (??), optional chaining (?.), dynamic import, String.prototype.matchAll, globalThis, and module namespace exports—explaining their syntax, behavior, and practical code examples.
This article traces JavaScript’s evolution, covering the enrichment of prototype methods, standardization of classes and modules, the rise of asynchronous patterns like callbacks, promises, generators, async/await, and modern syntax features such as block scope, symbols, BigInt, reflection, and useful syntactic sugar.