Metadata on CAVATICA

Files on CAVATICA are characterised by their content and metadata. The file content is physically stored on cloud storage bucket and is immutable (i.e. it is not possible to edit the content of the file on CAVATICA).

The Platform file also contains metadata and may contain tags. Metadata associated with files makes them searchable, keeping your file collection manageable as it grows. It also enables them to be properly grouped for analyses.

Overview

One of the most common reasons for failed tasks is missing or improper metadata. Lack of proper metadata increases the chances that tools and workflows will fail to run correctly. We recommend that you set the metadata fields for your input files before executing analyses on CAVATICA.

There are three ways to enter or change file metadata:

• Using the visual interface
• Using the Command Line Uploader
• Using the API

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Metadata rules

The following rules apply for the metadata on CAVATICA:

• Maximum number of metadata key-value pairs per file is 1000.
• Maximum length of a metadata key is 100 bytes (UTF-8 encoding).
• Metadata key must not contain characters . and $ .
• Maximum length of a metadata value is 300 bytes (UTF-8 encoding).
• It's not possible to update any metadata value belonging to metadata schema for a Dataset file.
• Metadata and tags can only be set for files. Folders aren't supported.
• Metadata keys and values are treated as case sensitive.

Metadata categories

The following metadata categories are available for each of the files:

• System metadata - file attributes which cannot be edited (except for the name attribute). 
• Metadata schema - all available metadata fields that can be specified for the file.
• Custom metadata - The custom metadata are the key-value pairs that you can define for each of your files. The custom metadata will not be validated on CAVATICA. The only rules that apply are the metadata rules described above.