Uploading CSV files

Steps

1. Open the dataset where you want to add a table.
2. Click Add table next to the dataset name in the sidebar.
3. Choose or drag in your CSV file.
4. Enter a table name using 1–64 lowercase letters, digits, or underscores. Start with a letter.
5. Click Upload and create Table.

Loam reads your file, infers the column types, creates the table, and inserts all the rows. You'll see the table appear in the sidebar.

How type inference works

Loam looks at the first 1,000 rows to figure out what each column contains:

• Columns that look like whole numbers become Int64
• Columns that look like decimal numbers become Float64
• Columns formatted as dates, such as 2026-07-18, become Date
• Columns formatted as supported ISO timestamps become DateTime
• Columns containing true and false become Bool
• Columns that do not consistently match a supported type become String

If the inferred type is wrong for your use case, you can re-upload with a Parquet file for types stored in the file.

File requirements

• The first row must be the header row (column names).
• Maximum file size: 100 MB.
• UTF-8 encoding.
• Use commas between fields.

What to expect

You'll see upload progress while the file transfers, followed by aValidating and committing status while Loam processes it. Keep the tab open until the table is ready.

After the upload completes, you can immediately query the data in the SQL Console (sign in to open this page) or open Explore from the table page.