Terms starting with "S"
SQL Window Functions
Window functions (ROW_NUMBER, RANK, LAG, LEAD, SUM OVER) perform calculations across a set of rows related to the current row without collapsing them into a single aggregate — enabling rankings, running totals, and comparisons within result sets.
6mo ago
Database intermediate
Structured Logging
PHP 8.0+
4
Emitting log entries as machine-parseable key-value pairs (JSON) rather than free-form strings — enabling filtering, aggregation, and alerting.
6mo ago
Observability intermediate
Safe Mode — What It Was & Why It Failed
PHP 3.0+
PHP's safe_mode (PHP 3–5.3) attempted to restrict multi-user PHP hosting at the language level — it was removed in PHP 5.4 after being proven ineffective and breaking legitimate code.
6mo ago
PHP intermediate
Saga Pattern
1
The Saga pattern manages distributed transactions across services using a sequence of local transactions — each step publishes an event, and compensating transactions undo completed steps on failure.
6mo ago
Messaging advanced
Scalar Type Declarations (PHP 7.0)
PHP 7.0+
PHP 7.0 added int, float, string, bool type declarations for function parameters — the biggest type safety leap in PHP history, enabling static analysis.
6mo ago
PHP beginner
Scheduler API (scheduler.postTask)
ES2021
The Scheduler API (scheduler.postTask) lets you prioritise async tasks — user-blocking, user-visible, or background — giving the browser hints to schedule work optimally.
6mo ago
JavaScript advanced
Semantic Search
Search that matches by meaning and intent rather than exact keywords — a query for 'how to prevent database attacks' finds SQL injection documentation even if those exact words never appear.
6mo ago
AI / ML intermediate
Semaphore
5
A semaphore is a generalised mutex that allows N concurrent accesses — a counting semaphore with value N lets N threads proceed, blocking the (N+1)th.
6mo ago
Concurrency intermediate
Service Discovery Patterns
The mechanism by which services in a distributed system locate each other's network addresses — eliminating hardcoded IPs by maintaining a registry that services register with and query at runtime.
6mo ago
Architecture intermediate
Service Worker
7
A JavaScript file that runs in the background separate from the web page, intercepting network requests to enable offline support, background sync, and push notification delivery.
6mo ago
Mobile intermediate
Short Open Tags History & Why to Avoid
PHP 3.0+
PHP's short tags (<? ?> and <?= ?>) have been problematic since PHP 3 — disabled by many hosting providers, conflicting with XML, and inconsistent across environments.
6mo ago
PHP beginner
SimpleXML — Parsing XML in PHP
PHP 5.0+
2
SimpleXML provides the fastest way to read well-formed XML in PHP — simplexml_load_string() or simplexml_load_file() returns an object where elements are properties and attributes are array-accessed, requiring no tree traversal.
6mo ago
PHP beginner
Simplifying Complex Conditional Logic
6
Complex conditionals can be simplified with De Morgan's laws, guard clauses, decomposing into named predicates, and consolidating duplicate conditions.
6mo ago
Style intermediate
SLO / SLI / SLA
SLI (what you measure), SLO (your internal target), SLA (your customer commitment) — the hierarchy that turns vague 'uptime' promises into measurable operational objectives.
6mo ago
Observability intermediate
Socket Programming with PHP
PHP 5.0+
1
PHP supports raw socket programming via the Sockets extension (socket_create) and stream sockets (stream_socket_client) — used for custom protocols, WebSocket servers, and network tools.
6mo ago
PHP advanced
Spans & Traces
A trace is one request's full journey; spans are the individual operations within it — each span has a name, start time, duration, status, and optional attributes.
6mo ago
Observability beginner
SPL Introduction — Standard PHP Library
PHP 5.0+
SPL (Standard PHP Library, PHP 5.0) added data structures, iterators, and interfaces — SplStack, SplQueue, SplHeap, ArrayObject, and the Iterator/Countable interfaces.
6mo ago
PHP intermediate
Spread Operator & Variadic Args (PHP 5.6)
PHP 5.6+
PHP 5.6 added variadic functions (...$args) and argument unpacking ($array...) — replacing func_get_args() and call_user_func_array() with clean syntax.
6mo ago
PHP beginner
sprintf() — Format Strings in PHP
PHP 4.0+
sprintf() builds a string by substituting typed placeholders (%s, %d, %f, %05d) with values — safer and more expressive than string concatenation or interpolation for formatted output, especially for numbers, padding, and locale-independent formatting.
6mo ago
PHP beginner
SQLite in Production
PHP 5.1+
2
SQLite is a serverless, file-based SQL database that is appropriate for production use in single-server applications, edge deployments, and embedded systems — with specific limitations around concurrent writes that make it unsuitable for multi-server setups.
6mo ago
Database intermediate