From delta-skills
Read and explain a specific commit from a Delta Lake transaction log. Use when the user wants to understand exactly what happened in a specific version — which files were added or removed, what the operation metadata says. Triggers on phrases like "show log", "explain commit", "what happened in version N", "read delta log", "inspect version".
How this skill is triggered — by the user, by Claude, or both
Slash command
/delta-skills:show-logThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Read and explain a specific Delta Lake commit file in detail. Opens the raw `_delta_log/XXXXXXXXXX.json` for the given version and explains every action inside it.
Read and explain a specific Delta Lake commit file in detail. Opens the raw _delta_log/XXXXXXXXXX.json for the given version and explains every action inside it.
/delta-skills:show-log path/to/table --version 5
Version is required.
TABLE_PATH="$1"
if [ ! -d "$TABLE_PATH/_delta_log" ]; then
echo "ERROR: No _delta_log directory found at $TABLE_PATH"
exit 1
fi
Delta log filenames are zero-padded to 20 digits:
VERSION=$(printf "%020d" $VERSION_NUMBER)
COMMIT_FILE="$TABLE_PATH/_delta_log/${VERSION}.json"
if [ ! -f "$COMMIT_FILE" ]; then
echo "ERROR: No commit file found for version $VERSION_NUMBER"
echo "File expected at: $COMMIT_FILE"
exit 1
fi
Each line is an independent JSON object (newline-delimited). Read all lines and categorize by action type:
commitInfo — operation metadatametaData — schema or config changeprotocol — reader/writer version requirementsadd — file added to the tableremove — file removed (logically deleted)txn — streaming transaction identifiercommitInfo — Always show in full:
metaData — If present, this was a schema or config change. Show:
delta.enableDeletionVectors, delta.autoOptimize)add actions — Summarize, don't list every file unless < 10:
remove actions — Same treatment as add:
dataChange is true (real deletion) or false (OPTIMIZE/compaction)protocol — If present, note the reader/writer version requirements. Highlight if this means older readers will break.
Commit: version 42 — tables/customers
─────────────────────────────────────────────────────
Operation: MERGE
Timestamp: 2025-03-18 09:12:33 UTC
Engine: Apache-Spark/3.5.0 Delta-Lake/3.3.0
Isolation: Serializable
User: [email protected]
Metrics:
numSourceRows: 24,000
numTargetRowsInserted: 1,204
numTargetRowsUpdated: 11,196
numTargetRowsDeleted: 0
numOutputRows: 12,400
executionTimeMs: 18,432
Files added (14 files, 284 MB total):
part-00000-abc123.snappy.parquet (country=FI, 22 MB, 94,200 rows)
part-00001-def456.snappy.parquet (country=SE, 19 MB, 81,400 rows)
part-00002-ghi789.snappy.parquet (country=DE, 24 MB, 103,100 rows)
... and 11 more
Files removed (14 files, 281 MB total):
These files are logically deleted. They remain on disk until VACUUM runs.
dataChange: true — this was a real data modification, not a compaction.
commitInfo is missing → note this is unusual and show what actions are presentremove actions with dataChange: false are from OPTIMIZE or similar compaction — no actual data was deletedadd.stats contains column-level min/max/nullCount — very useful for understanding data distributionnpx claudepluginhub chanukyapekala/delta-skills --plugin delta-skillsExplores Bauplan lakehouse data using Python SDK: inspect namespaces, tables, schemas, samples, profiling queries; export results to files. Read-only, phased execution produces summary.md.
Queries Databricks Unity Catalog system tables for audit, lineage, billing, compute, jobs; manages volumes with upload, download, list, and directory operations.
Generates SQL validation notebooks for dbt PR changes with before/after comparison queries. Useful for data teams validating model changes before deployment.