feat(DENG-8178): search_clients_daily_glean_v1

[kbammarito]

Description

search_derived.search_clients_daily_glean_v1

A Glean-based daily search aggregate, one row per client_id, submission_date, normalized_engine, partner_code and source. It runs alongside search_clients_daily_v8; the seven legacy_ columns carry a v8-comparable number from this table alone.

Nothing consumes it yet, so nothing in production changes when this merges.

• The query, schema and metadata, plus the user-facing view search.search_clients_daily_glean
• Three sides combined with full outer joins, so a row survives if SERP impressions, sap.counts events or the legacy_ counters have activity for the key
• date_partition_offset: -1, because serp_events_v2 writes the previous day's partition — without it every SERP measure would publish as 0, silently
• A shredder delete target on the Glean client_id
• Two query tests — test_sides covers the four side combinations, test_legacy_labels the label shapes and partner-code attribution
• A description on all 81 fields and 6 nested entries

Post-merge

• The backfill, after serp_events_v2's finishes. The floor is the rolling 775-day partition expiry, so the range is computed against the run date
• Bigeye monitoring. A monitor can't be declared before the table exists in production

Related Tickets & Documents

• DENG-8178
• feat(DENG-8178): build search_clients_daily_v9 #7744

Reviewer, please follow this checklist

[github-actions]

⚠️ Sensitive-data flow detected — cc @mozilla/dataplatform-wg, please review.

A changed query reads restricted / workgroup-gated data and writes it to a more broadly readable destination that no team owns:

- moz-fx-data-shared-prod.revenue (unresolved (treated as sensitive)) -> moz-fx-data-shared-prod.search_derived
    grants read to workgroup:mozilla-confidential/data-viewers not authorized on the source
    needs Data Platform (@mozilla/dataplatform-wg) review

A source shown as unresolved has no dataset_metadata.yaml in this repo. It may be
defined outside bigquery-etl — in private-bigquery-etl, or in a project this repo does
not manage — in which case its access could not be read and it is flagged conservatively.

This is advisory and does not block merge.
A Data Platform reviewer should confirm the widened access is intended, or narrow the destination's workgroup_access.

[github-actions]

This PR adds search_derived.search_clients_daily_glean_v1 (query, schema, metadata, README), the user-facing view search.search_clients_daily_glean, a Glean client_id shredder target, and two query tests with shared source-schema fixtures. Nothing reads the table yet.

I checked the grain and the three-way full outer join for fan-out and null-key collapse and did not find a problem: join-1 output keys are unique, legacy_cte.partner_code is non-null by the 'unknown_code' sentinel, and the COALESCE(serp, sap) predicates on join-2 keep legacy-only keys one-sided rather than duplicating them. The date_partition_offset: -1 rationale matches how serp_events_v2 writes its partition, the metrics.url / metrics.url2 split is right (events_stream_v1's metrics_to_json moves url2 to $.url), NUMERIC matches mozfun.norm.browser_version_info, the shredder entry pairs with DESKTOP_GLEAN_SRC correctly, and schema.yaml field order matches final_cte's select list. Test coverage of the label shapes and the unknown_code orphan-ad path is good.

Four findings inline: two in the SERP/join logic, one convention violation on the SERP source reference, and one suggestion about the legacy tab-count aggregation. Per the reviewer checklist, the Bigeye monitor and backfill are deferred to post-merge per the PR description, and no backfill.yaml is touched here.

[gkabbz]

Sorry @Standard8 I hit the re-review button by accident.

[irrationalagent]

fixes look good to me - thank you @kbammarito !

[scholtzan]

Integration report

• View full diff, if available (SQL + DAGs) (requires private-bigquery-etl access)
• Private CI run
• Bigeye monitoring dry-run: ✅ plan clean — view plan (requires private-bigquery-etl access)