Learn what types of data can be used as metadata in a data table (including arrays!) - what they are and how to specify them in Terra.
What are attributes?
Attributes are input variables or metadata - any data stored in a column of a table in a Terra workspace. The column header identifies what attribute (data) is in the column. The attribute (data) itself is in the table cell in a row.
You can specify the type of data in a column when you add data to a table in Terra, such as when you add a row or a column to a table, or when you edit a table cell.
Sample table with metadata attributes sample_id, participant, r1_fastq
Five samples of data from the same mouse. Each sample is one fastq data file corresponding to a particular flow lane.
Terra supported attribute types
- String (this type includes links to data files in cloud storage. Terra will automatically convert the text to a link)
- Reference (field is an attribute from another table)
Array attributes in a table
Note that you can make any attribute in a table an array of the above data types. For example, below is the same data as in the example above but configured as a single sample (row) with an array in the fastq column instead of five separate rows of sample data.
Sample table with attributes sample_id, participant, r1_fastq (array)
The same five data files in an array. The data are contained in a single sample row in the table.
The same data as a sample_set table
The sample_set table is functionally the same as the second example above. Which configuration you use will depend on what your workflow expects.
How to specify an array attribute in a table
When editing data in a table
Choose "Value is a list" and then "+ Add item" to add each value in the array.
Adding a column (attribute) to an existing table
Choose "Value is a list" and "+ Add item" to add each value in the array.
To learn more, see How to add an array of files to a data table.