chore(DENG-10722): initiate backfill for urlbar_events_v2

[kbammarito]

Description

This PR backfills urlbar_events_v2 after additions in #9246

Related Tickets & Documents

• DENG-10722

Reviewer, please follow this checklist

[github-actions]

Claude finished @kbammarito's task in 2m 13s —— View job

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Claude Code Review

• Read the changed file (backfill.yaml)
• Check existing backfill entries / context for urlbar_events_v2
• Review against backfill conventions / recommended practices
• Post review feedback

Note: I attempted to post this as a formal GitHub review (with inline comments on the relevant lines), but the mcp__github__create_and_submit_pull_request_review and mcp__github_inline_comment__create_inline_comment tools weren't permitted in this run. Folding the feedback into this comment instead. See the FAQ for permission configuration.

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Summary

The new entry is well-formed and passes the structural rules in bigquery_etl/backfill/validate.py:

• Entry date 2026-05-01 is 7 days old — well inside the 28-day MAX_BACKFILL_ENTRY_AGE_DAYS cutoff.
• start_date 2025-01-01 is 486 days before the entry date, comfortably under the 775-day NBR_DAYS_RETAINED limit, so no override_retention_limit is needed.
• Entries remain sorted by entry date (descending); only one Initiate entry exists.
• Watchers are concrete addresses (no default), all override flags are explicit, shredder_mitigation: false is consistent with the rest of the file.

Two non-blocking points worth confirming before merging — both have material cost implications.

1. Significant overlap with prior completed backfills

backfill.yaml:1-12 — The new range 2025-01-01 → 2026-05-01 fully re-processes the window already covered by the three Complete entries below it:

Entry date	Covered range	Status
2026-03-25	2025-01-01 → 2025-01-31	Complete
2026-03-30	2025-02-01 → 2025-04-30	Complete
2026-03-31	2025-05-01 → 2026-03-31	Complete

If #9246 added columns that need to be populated retroactively across the full window, a full rebackfill is the right call. But it redoes ~15 months of previously-Complete work, which is non-trivial in slot/storage cost (per docs/reference/recommended_practices.md § Large Backfills, this also moves data out of long-term storage for ~90 days). Worth a sanity check that this is intentional vs. scoping the new entry to just the gap (2026-04-01 → 2026-05-01) — or to whatever partitions still have NULLs for the new fields.

Also — the previous unsuccessful single-shot attempts (2026-03-20 and 2026-03-27, both Cancelled) suggest that a single 16-month entry has historically been at the edge of what runs cleanly here. A staged approach (mirroring the successful smaller chunks) would lower the blast radius if something fails partway through.

2. reason could carry more context

backfill.yaml:4 — The link to DENG-10722 is useful, but referencing the schema-changing PR (#9246) directly in the reason — and ideally naming the new fields being populated — would make the intent self-documenting in the file, matching the more descriptive style used in older entries (2026-03-25, 2026-03-30, 2026-03-31). Suggestion:

reason: Backfill new fields added in https://github.com/mozilla/bigquery-etl/pull/9246 (DENG-10722).

Reminder

Per recommended_practices.md § Large Backfills, please validate the run afterwards via monitoring.bigquery_usage for slot/byte usage and any errors once the job completes.

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• Branch: DENG-10722-initiate-backfill-urlbar-events-v2

[alekhyamoz]

lgtm

[github-actions]

Integration report for "chore(DENG-10722): initiate backfill for urlbar_events_v2"

sql.diff

Click to expand!

diff -bur --no-dereference --new-file /tmp/workspace/main-generated-sql/sql/moz-fx-data-shared-prod/firefox_desktop_derived/urlbar_events_v2/backfill.yaml /tmp/workspace/generated-sql/sql/moz-fx-data-shared-prod/firefox_desktop_derived/urlbar_events_v2/backfill.yaml
--- /tmp/workspace/main-generated-sql/sql/moz-fx-data-shared-prod/firefox_desktop_derived/urlbar_events_v2/backfill.yaml	2026-05-14 16:53:58.070325657 +0000
+++ /tmp/workspace/generated-sql/sql/moz-fx-data-shared-prod/firefox_desktop_derived/urlbar_events_v2/backfill.yaml	2026-05-14 16:53:53.102272516 +0000
@@ -1,3 +1,15 @@
+2026-05-14:
+  start_date: 2025-01-01
+  end_date: 2026-05-14
+  reason: Backfill new fields added in DENG-10722, PR 9246
+  watchers:
+  - kbammarito@mozilla.com
+  - nflorez@mozilla.com
+  status: Initiate
+  shredder_mitigation: false
+  override_retention_limit: false
+  override_depends_on_past_end_date: false
+  ignore_date_partition_offset: false
 2026-03-31:
   start_date: 2025-05-01
   end_date: 2026-03-31

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