모든 문서
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Rust FFI resource ownership: pair the foreign constructor with its actual destructor
Make allocation, release and callback lifetime explicit in a narrow Rust wrapper around foreign resources.
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Bulk operations instead of per-row loops: round trips, transactions and COPY
A loop that sends one statement per row pays a round trip, a parse and often a commit per row; a bulk operation sends the set in one statement, one stream or one transaction. PostgreSQL's own guidance is to commit once, use COPY for loads and build indexes after loading; client libraries offer executemany and copy for the same reason.
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Network throughput and retransmits on Linux: ss -ti, nstat, and iperf3
ss -ti shows one connection's own retransmission and RTT view; nstat reports the same kind of counters host-wide from the kernel's SNMP and extended TCP statistics; iperf3 measures achievable throughput directly when retransmits are low but throughput still disappoints.
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A first game day: one chaos experiment with a hypothesis, a blast radius and an abort rule
Run a first fault-injection exercise as a scheduled, announced experiment: define the steady state as a measurable output, hypothesise that it holds under one specific fault, limit the blast radius, set an abort condition, inject, and record what the system and the people did; the Principles of Chaos Engineering give the four steps and the Google SRE book describes disaster role-play as a weekly ritual.
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Reasoning about complexity before optimising
Asymptotic complexity predicts how run time grows with input size; recognising quadratic loops, repeated linear searches and unbounded recursion in code review prevents most performance incidents before profiling is needed.
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Separating HDR lighting, exposure, tone mapping, and display output
Use explicit stages to preserve bright scene information, set exposure predictably, and generate a signal appropriate for the target display.
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A wrist step counter and a pocket phone diverge more on days with many short walking bouts and occupied hands
Hypothesis: two consumer step counters worn by one person, one on the wrist and one in a trouser pocket, disagree by a larger fraction on days the diary marks as many short walks or hands occupied (pram, bags, trolley) than on days with a few long walks, because the two devices read different body motions; a daily log with both devices stated is proposed as the test and no measurement is reported.
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Protocol Buffers deterministic serialization is not a canonical message identity
Avoid using arbitrary protobuf bytes as a stable semantic fingerprint across runtimes and versions.
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Separating the acting service from the represented user in delegation tests
Test a delegated action with both the executing service identity and the user it represents visible in the oracle. This proposed method avoids treating successful service authentication as sufficient proof of user authority.
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HTTP keep-alive and connection reuse: pools, idle timeouts and the stale-connection race
HTTP/1.1 keeps a connection open for further requests unless a Connection: close is sent, which removes a TCP and TLS handshake from every request after the first; the client must keep a pool for the life of the process, read every response body, and set its idle timeout below the server's so it does not reuse a connection the server has already closed.
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APT pinning: keeping one package on a chosen version or source with preferences files
APT pinning lets an operator hold a single package back, pull it from a non-default suite, or prevent a future apt upgrade from touching it — configured per file under /etc/apt/preferences.d rather than by editing one shared file, and inspected with apt-cache policy.
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AdamW: 분리된 가중치 감쇠가 L2 페널티와 다른 이유
AdamW는 적응적 기울기 업데이트와 별개로 파라미터를 축소한다. 감쇠 항은 Adam의 모멘트 추정에 들어가지 않지만 학습률, 업데이트 횟수, 파라미터 그룹은 여전히 정규화에 영향을 준다.
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Reading, granting, and backing up NTFS permissions with icacls and Get-Acl/Set-Acl
icacls reads and grants NTFS permissions and encodes inheritance as (OI)(CI) flags; icacls /save and /restore back up and reapply an entire ACL tree before a change, and Get-Acl/Set-Acl give the same information as PowerShell objects.
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Improvements measured after targeting the worst-performing cases are partly regression to the mean
Hypothesis: when an engineering effort selects the worst-scoring endpoints, tests, hosts or tenants by a noisy metric and reports their improvement after intervention, a substantial part of the reported gain would have occurred without the intervention, because extreme measurements tend to be followed by less extreme ones. A proposed test with an untouched control group is described.
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Shader derivatives: preserve valid gradients across branches and UV seams
Diagnose unstable texture footprints by distinguishing continuous coordinates, explicit gradients and derivative operations in divergent fragment-shader control flow.
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Service level objectives and error budgets
An SLO is a target for a service level indicator such as availability or latency; the difference between the target and 100% is an error budget that decides how much risk releases may take.
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A day-one setup script that verifies itself: bootstrap, doctor, smoke test
One command after cloning either produces a working environment or a precise list of what is missing and how to fix it: a read-only doctor script checks every requirement, an idempotent bootstrap installs only what the checks report missing, and a smoke test decides the exit status; CI runs it from a clean machine so it cannot rot between newcomers.
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Datenqualitätsprüfungen: Aktualität, Menge, Nullwerte und Eindeutigkeit als Mindestsatz
Vier billige Prüfungen fangen die meisten kaputten Ladeläufe: Ist die Quelle frisch genug, kam eine plausible Zeilenzahl, sind Schlüssel und Kennzahlen gefüllt, ist die erklärte Körnung eindeutig? Jede Prüfung als Abfrage formulieren, die fehlerhafte Zeilen liefert, nach dem Laden und vor dem Veröffentlichen ausführen, Warnung und Blockade trennen.
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Confidence intervals in outline: what the interval says and what it does not
A 95% confidence interval comes from a procedure that captures the true value in 95% of repeated samples; one particular interval either contains it or not. Its width shrinks with the square root of the sample size and grows with the spread. Read it as the range of values compatible with the data, report it next to every estimate, and compute the interval of a difference when comparing.
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Safe archive extraction: path traversal in zip and tar
Archive entries can carry names like ../../etc/passwd or absolute paths and symlinks; extract only after resolving each target path and checking it stays inside the destination, reject links pointing outside, and cap total size and entry count.
기계 판독 가능: JSON