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Pivot Lake's "Memory Latency, Stupid" post on GROUP BY hits HN front page

Pivot Lake publishes memory-latency explainer on GROUP BY performance

1 Oct 29 12:22 PM · 14d ago · 1 post · 1 source · development 1 of 5

The post explains CPU cache hierarchy and memory access latency, then benchmarks a naive single-core GROUP BY over 99 million rows with ~17 million unique keys, taking 3.9 seconds. It is first submitted to Hacker News with little initial traction.

Pivot Lake Database engine vendor and blog author

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Peak 5 pieces in 4h at Oct 31, 12 PM; 21 pieces over 15 days (2 articles · 6 posts · 13 comments) Oct 29, 12 PM — 2 pieces · 2 posts — Hacker News 1, Reddit 1Oct 29, 4 PM — quietOct 29, 8 PM — quietOct 30, 12 AM — quietOct 30, 4 AM — quietOct 30, 8 AM — 1 piece · 1 post — Hacker News 1Oct 30, 12 PM — quietOct 30, 4 PM — quietOct 30, 8 PM — quietOct 31, 12 AM — quietOct 31, 4 AM — quietOct 31, 8 AM — quietOct 31, 12 PM — 5 pieces · 2 articles · 1 post · 2 comments — Hacker News 3, Newswires 2Oct 31, 4 PM — 5 pieces · 1 post · 4 comments — Hacker News 4, Mastodon 1Oct 31, 8 PM — 2 pieces · 2 comments — Hacker News 2Nov 1, 12 AM — 1 piece · 1 comment — Hacker News 1Nov 1, 3 AM — 2 pieces · 1 post · 1 comment — Hacker News 1, Mastodon 1Nov 1, 7 AM — quietNov 1, 11 AM — 1 piece · 1 comment — Hacker News 1Nov 1, 3 PM — 2 pieces · 2 comments — Hacker News 2Nov 1, 7 PM — quietNov 1, 11 PM — quietNov 2, 3 AM — quietNov 2, 7 AM — quietNov 2, 11 AM — quietNov 2, 3 PM — quietNov 2, 7 PM — quietNov 2, 11 PM — quietNov 3, 3 AM — quietNov 3, 7 AM — quietNov 3, 11 AM — quietNov 3, 3 PM — quietNov 3, 7 PM — quietNov 3, 11 PM — quietNov 4, 3 AM — quietNov 4, 7 AM — quietNov 4, 11 AM — quietNov 4, 3 PM — quietNov 4, 7 PM — quietNov 4, 11 PM — quietNov 5, 3 AM — quietNov 5, 7 AM — quietNov 5, 11 AM — quietNov 5, 3 PM — quietNov 5, 7 PM — quietNov 5, 11 PM — quietNov 6, 3 AM — quietNov 6, 7 AM — quietNov 6, 11 AM — quietNov 6, 3 PM — quietNov 6, 7 PM — quietNov 6, 11 PM — quietNov 7, 3 AM — quietNov 7, 7 AM — quietNov 7, 11 AM — quietNov 7, 3 PM — quietNov 7, 7 PM — quietNov 7, 11 PM — quietNov 8, 3 AM — quietNov 8, 7 AM — quietNov 8, 11 AM — quietNov 8, 3 PM — quietNov 8, 7 PM — quietNov 8, 11 PM — quietNov 9, 3 AM — quietNov 9, 7 AM — quietNov 9, 11 AM — quietNov 9, 3 PM — quietNov 9, 7 PM — quietNov 9, 11 PM — quietNov 10, 3 AM — quietNov 10, 7 AM — quietNov 10, 11 AM — quietNov 10, 3 PM — quietNov 10, 7 PM — quietNov 10, 11 PM — quietNov 11, 3 AM — quietNov 11, 7 AM — quietNov 11, 11 AM — quietNov 11, 3 PM — quietNov 11, 7 PM — quietNov 11, 11 PM — quietYesterday, 3 AM — quietYesterday, 7 AM — quietYesterday, 11 AM — quietYesterday, 3 PM — quietYesterday, 7 PM — quietYesterday, 11 PM — quiet 1–234–5
1–2Pivot Lake publishes memory-latency…3Post resubmitted to HN under a new title4–5Post is shared on Mastodon
Oct 30Nov 1Nov 3Nov 5Nov 7Nov 9Nov 11now · 1:12 AM ET

What was reported 1 claim about this development

  1. 2 outlets It's the memory latency, stupid

    first by HN Best, 12d ago · also HN Frontpage

All 5 developments of Pivot Lake's "Memory Latency, Stupid" post on GROUP BY hits… →

RedditHacker NewsNewswiresMastodon