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Data Quality in Transformations
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Data Quality in Transformations

HardSQL · PostgreSQL

Problem

How do you handle data quality issues or missing values during a transformation process at Roblox?

Using the provided Roblox experience and raw event tables, write a query that validates event records, treats missing creator identifiers as unknown, excludes invalid visit counts from totals, and preserves experiences with no valid events.

Output

  1. One row per experience with experience_id, experience_name, valid_event_count, invalid_event_count, valid_visit_total, missing_creator_event_count, and quality_status.
  2. Include every experience, order by experience_id ascending, and label each status as ready, review, or no_valid_events.

Schema

experiences
ColumnTypeDescription
experience_idPKINTRoblox experience identifier
experience_nameVARCHAR(120)Display name of the experience
raw_experience_events
ColumnTypeDescription
raw_event_idPKINTRaw event identifier
experience_idINTReferenced experience identifier, which can be missing or unmatched
event_typeVARCHAR(30)Raw event type
event_tsTIMESTAMPEvent timestamp
visit_countINTVisit count reported by the event
creator_idVARCHAR(40)Creator identifier, which may be null or blank
Tablesexperiencesraw_experience_events
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