Terms starting with "P"
Prompt Caching
API feature where a static prompt prefix (system instructions, large context) is cached server-side, dramatically reducing cost and latency on repeated calls that share the prefix.
1w ago
ai_ml intermediate
PDO Error Handling PHP 5.1+
PDO has three error modes — silent, warning, and exception — controlling how database errors surface.
1mo ago
php beginner
PDO Fetch Modes PHP 5.1+
Constants controlling how PDO returns rows — as arrays, objects, or custom classes.
1mo ago
php beginner
PDO lastInsertId() PHP 5.1+
Returns the auto-increment ID generated by the most recent INSERT statement.
1mo ago
php beginner
PDO Named Placeholders PHP 5.1+
Named parameters (:name) in prepared statements — more readable than positional ? placeholders for queries with multiple parameters.
1mo ago
php beginner
PDO query() vs prepare() PHP 5.1+
PDO query() executes raw SQL immediately — prepare() parameterises it. query() must never include user-controlled values.
CWE-89 OWASP A3:2021
1mo ago
php beginner
9.8
PDO Transactions PHP 5.1+ PDO wraps multiple queries in an atomic unit — either all succeed or all roll back.
1mo ago
php intermediate
PDO::ATTR_EMULATE_PREPARES PHP 5.1+
Controls whether PDO sends real prepared statements to the database or emulates them client-side in PHP.
CWE-89 OWASP A3:2021
1mo ago
php intermediate
PDOStatement::bindParam() vs bindValue() PHP 5.1+
Two PDO methods for binding variables to placeholders — bindParam() binds by reference (evaluated at execute), bindValue() binds by value (evaluated immediately).
1mo ago
php intermediate
PDOStatement::rowCount() PHP 5.1+
Returns the number of rows affected by the last DELETE, INSERT, or UPDATE — unreliable for SELECT.
1mo ago
php beginner
PHP Generators PHP 5.5+
Functions using yield that produce values lazily — one at a time — instead of building a complete array in memory.
1mo ago
php intermediate
Prompt Injection Attack An attack where crafted user input overrides or hijacks an LLM's system instructions, causing it to ignore its intended behaviour and follow attacker-supplied commands instead.
CWE-74 OWASP LLM01:2025
1mo ago
ai_ml advanced
PHP Fibers — Internals & Scheduler Patterns PHP 8.1+ How PHP Fibers work under the hood — stack allocation, suspension mechanics, and how to build a cooperative multitasking scheduler on top of the Fiber API introduced in PHP 8.1.
1mo ago
php advanced
prefers-reduced-motion — Accessible Animations
A CSS media query and JavaScript API that detects when a user has requested reduced motion in their OS settings, allowing you to disable or simplify animations that can trigger vestibular disorders.
1mo ago
accessibility beginner
P50/P95/P99 Latency Percentiles
Latency percentiles (P50, P95, P99) tell you what most users experience — P99 means '99% of requests are faster than this', revealing the worst experiences that averages hide.
2mo ago
observability beginner
Page Visibility API HTML5
The Page Visibility API tells you when a tab is hidden or visible — use it to pause animations, polls, and video when the user switches tabs.
2mo ago
javascript beginner
password_hash() — Native Bcrypt (PHP 5.5) PHP 5.5+
PHP 5.5 added password_hash() and password_verify() — the only correct way to hash and verify passwords. Never use MD5, SHA1, or unsalted hashes.
2mo ago
php beginner
PCNTL Signals in CLI PHP PHP 7.1+
The PCNTL extension lets CLI PHP scripts handle OS signals (SIGTERM, SIGINT, SIGUSR1) — enabling graceful shutdown and hot reload in long-running daemons.
2mo ago
php advanced
Permissions API HTML5
The Permissions API (navigator.permissions.query()) lets you check the current state of browser permissions — granted, denied, or prompt — before requesting sensitive APIs.
2mo ago
javascript intermediate
Pessimistic Locking
Pessimistic locking acquires an exclusive lock immediately on read — preventing any concurrent modification. Right for high-contention scenarios but reduces throughput.
2mo ago
concurrency intermediate