column_stats is the baseline component. It powers dataset summaries shown to Summand and the schema-level views the rest of the product builds on. It runs when you select it in an experiment or when Summand runs it from chat.
Separately, every ingest writes a lighter set of per-column statistics (row and null counts, minimums and maximums) read from the table’s metadata. That set is available as soon as ingestion finishes, without running this component.
What it computes
For every column in the dataset:- Common stats —
name,dtype,count,nullCount,nullPct,uniqueCount,uniquePct. - Numeric columns —
min,max,mean,median,std, first and third quartiles,zeroCount,zeroPct. - Categorical / string columns — top 10 distinct values with counts.
totalRows, totalColumns.
Inputs
None.column_stats takes no configuration — it always runs on the full dataset.
Output shape
column_stats.json to the dataset’s versioned S3 path.
Where it shows up
- Dataset detail → Components tab shows the latest
column_statsartifact column by column. - Summand chat queries it via the
analyzetool — “What’s the missingness ofrevenue?” resolves to a filtered read of the artifact.
Compute profile
For most datasets this finishes in a few seconds. The component reads the curated Parquet, computes the stats in pandas, and writes the JSON.