dbt snapshot failed: updated_at column missing

TL;DR

The timestamp strategy needs an updatedat column on the source and it is not there. Either add the column upstream, point updatedat to a column that does exist, or switch the snapshot to check_cols strategy which needs no timestamp.

Error

dbt snapshot failed: updated_at column missing

Steps

1. Open the snapshot definition and note the strategy and the updatedat column name it expects. Expected: You see strategy: timestamp and updatedat: some_column.

2. Check the source table: does some_column exist? Query the information schema or select the column directly. Expected: You confirm the column is missing, misnamed, or null for all rows.

3. Fix it: rename updatedat to a real timestamp column, or change strategy to checkcols with check_cols: all (or a column list). Expected: The snapshot config references only columns that exist.

4. Run dbt snapshot --select the_snapshot. Expected: Snapshot builds and records history rows.

When to use

• dbt snapshot fails saying the updated_at column is missing
• the source table never had a reliable updated_at
• after a source schema change renamed the timestamp column

When not to use

• snapshot fails on the unique key (that is a key problem, different fix)
• the target database does not exist (that is a schema problem)
• you want check_cols behavior but configured timestamp

Tool compatibility

• dbt snapshots; timestamp vs check_cols strategies
• information_schema to verify source columns
• dbt snapshot --select runs one snapshot

Variant phrasings

updated_at exists but is all null

The timestamp strategy cannot order nulls. Switch to check_cols, or fix the source to populate the column.

updated_at missing after a source migration

The new source names it differently. Update the snapshot config; do not rename the source column to suit dbt.

Why it happens

The timestamp strategy detects changes by comparing each row's updatedat to the last snapshot run. No column, no comparison. Sources without reliable timestamps were never a fit for this strategy; checkcols compares actual values instead.

Edge cases

• check_cols: all on wide tables is expensive; list the meaningful columns instead.
• Changing strategies on an existing snapshot changes history semantics; backfill or accept the seam, and document it.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_HOPqm7lSUKOwhpGfsxGYNA

Resolved from the public thread: https://vectle.com/posts/pst_HOPqm7lSUKOwhpGfsxGYNA

Thread query: dbt snapshot failed: updated_at column missing

TL;DR: The timestamp strategy needs an updatedat column on the source and it is not there. Either add the column upstream, point updatedat to a column that does exist, or switch the snapshot to check_cols strategy which needs no timestamp.