+
+ CDS migration progress, 2015–2026
+ Legacy CDS (cds.cern.ch) total record count (estimated including restricted records), plotted on the same scale as cumulative records migrated into repository.cern, cumulative books held in catalogue.library.cern since its 21 April 2021 launch, and cumulative videos held on videos.cern.ch since the 2017 migration.
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+ Legacy CDS total records (est. incl. restricted)
+ repository.cern cumulative records
+ catalogue.library.cern cumulative records
+ videos.cern.ch cumulative records
+ Migration milestone
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+ View underlying data (Wayback Machine snapshots & migration events)
+
+ Legacy CDS (cds.cern.ch) — Wayback Machine snapshots
+ Snapshot date Public count (scraped) Retroactive adjustment Est. total incl. restricted (plotted) repository.cern migrated to date Net of repository.cern
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+ repository.cern — migration events
+ Date Content migrated Records added Cumulative total
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+ catalogue.library.cern — books created per year (via /api/documents)
+ Period Books created Cumulative total
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+ videos.cern.ch — videos created per year (via /api/records)
+ Period Videos created Cumulative total
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+ Legacy CDS source: record counts scraped from the CDS homepage as captured by the Internet Archive Wayback
+ Machine (web.archive.org, cds.cern.ch), which reflects only publicly visible records. The
+ confirmed current total including restricted records is 592,089 (2 August 2026); comparing that to the
+ closest scraped snapshot (566,063, 18 July 2026) implies roughly 26,026 restricted records are not shown by
+ the public counter. Since we have no historical breakdown of restricted records, that offset is extrapolated
+ as a constant and added to every earlier scraped snapshot to estimate a total-including-restricted series
+ (shown in the data table); this assumes the restricted share has stayed roughly flat in absolute terms, which
+ is a simplification. The final point uses the confirmed live total (592,089, 2 August 2026) directly as its
+ total, rather than a scraped-plus-offset estimate. Every other plotted point carries a
+ retroactive adjustment , summing three components, so the total line depicts the drop each
+ repository.cern migration should produce even though the scraped public counter itself never dips at those
+ dates (that content isn't purged from legacy CDS on migration). Component A covers CERN Bulletin &
+ Courier, IT department, and HR content (Nov 2025 – Jan 2026): every point from 2015 through Jan 2024
+ carries the same flat allowance (~111,000–114,000, an approximate reconstruction of that content's
+ size) since none of it had migrated yet; it tapers to +63,000 after CERN Bulletin and Courier moved (Nov
+ 2025), +3,000 after IT department content moved (Dec 2025), and 0 once HR content had also moved (Jan
+ 2026). Component B covers Staff Association content and the ALEPH/DELPHI/L3/OPAL research records (Jul
+ 2026): a flat +13,000 on every point up to 29 July 2026, then 0. Component C covers theses (12,000): a flat
+ +12,000 on every point up to the 15 May 2025 migration, then 0. The three sum, so points before Nov 2024
+ carry all three, points from Nov 2024 through early May 2025 carry A and C, and points from late May 2025
+ through Jan 2026 carry only B (or A tapering alongside it from Nov 2025). Three points (Nov & Dec 2024,
+ Oct 2025) have no underlying wayback snapshot and are linearly interpolated between the nearest real ones
+ before any adjustment is applied; the data table below marks every reconstructed or boosted point. A
+ net-of-repository.cern figure — the total minus the cumulative amount migrated to
+ repository.cern by that date — is also computed and shown in the hover tooltip and the data table, for
+ readers who want legacy CDS's content net of what's already been migrated out. Neither retroactive
+ adjustment nor the net-of-repository.cern subtraction applies to the videos.cern.ch or catalogue.library.cern
+ migrations, since that content did not move to repository.cern.
+ repository.cern source: cumulative total (130,000) built from known migration batch sizes at each event date
+ (no continuous archive exists for this newer platform), including a ±1,500 reconciliation against the
+ confirmed live total to account for imprecise per-event estimates. catalogue.library.cern source: current
+ total holdings (211,323) queried live from the public /api/documents endpoint; yearly
+ books-created counts from the same endpoint's _created field, from 21 April 2021 onward, account
+ for 84,508 of that total, with the remaining 126,815 reconstructed as the baseline migrated on launch day (its
+ original bibliographic creation dates are preserved from the legacy system, so it isn't separately
+ timestamped as "migrated"). videos.cern.ch source: current total holdings (39,000, including restricted)
+ queried live; yearly videos-created counts from the public /api/records endpoint's
+ _created field, from 2017 onward, account for 17,357 of that total, with the remaining 21,643
+ reconstructed as the baseline migrated during the 2017 bulk migration from legacy CDS. Both the
+ catalogue.library.cern and videos.cern.ch lines therefore step from 0 to their reconstructed baseline at
+ launch and grow to their live totals from there. All four series share a single record-count scale. Data
+ compiled 2 August 2026.
+
+