# Missing Columns & NULL Values

If you’ve noticed some missing columns or data from your data warehouse, the root cause may be `NULL` values.

## Stitch Replication

When Stitch loads your data, it uses the column’s data type to determine how to correctly store the data in your data warehouse. If a column only contains `NULLs`, Stitch’s loading processes won’t be able to infer the correct data type to store the data properly.

In short: when a column only contains `NULLs`, it won’t be replicated to your data warehouse.

## Next Steps

If you notice some missing columns, we recommend checking to see if they contain only `NULLs`. If this is the case, should that column at any point contain non-`NULL` values in the future, the column will immediately be created in your data warehouse and populated with the non-`NULL` values.

## Contacting Support

If you check the columns and find they contain values that are non-null, please reach out to support.