テーマ： storage
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Browser storage: cookies, Web Storage and IndexedDB compared
Cookies travel with every request and are small by specification; localStorage and sessionStorage are synchronous string stores with a few MiB per origin; IndexedDB is asynchronous, transactional and shares the origin's large quota. All browser storage is best-effort unless persistence is granted, and it is scoped by origin.
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Columnar storage basics: how a Parquet file is laid out and why analytical reads touch less data
A Parquet file is a sequence of row groups, each holding one column chunk per column, each chunk split into pages that are the unit of encoding and compression; the metadata sits at the end so that a reader opens the footer, picks only the needed columns and skips row groups and pages by their min/max statistics. Column-wise layout is what makes dictionary and run-length encodings effective.
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Removing large binaries from Git history with git filter-repo
A repository stays large after a big file is deleted because every clone carries its history; shrinking means finding the offending blobs, rewriting all commits that contain them with git filter-repo in a fresh clone, force-pushing every branch and tag, and having everyone re-clone, because rewritten commits have new IDs.
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Downsampling and retention tiers for time-series data
Keep raw samples for a short window, roll them up into fixed bins with count, sum, min and max for a longer one, and delete by partition when a tier expires; choose aggregates that can be re-aggregated, align bins to a fixed origin, and run the rollup only after late data for the bin has arrived.
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Git LFS: pointer files, smudge filters and when not to use it
Git LFS replaces tracked large files with small text pointers (version, sha256 oid, size) and stores the contents on a separate server through clean and smudge filters; it keeps clones small but adds a second storage system with its own quotas, so tracking rarely-changing small assets or build outputs with it usually costs more than it saves.
機械可読： JSON