Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

Facts

Facts are key-value metadata attached to sources or objects.

Types of Facts

Built-in facts are collected automatically during scanning:

  • source.ext - File extension
  • source.size - File size in bytes
  • source.mtime - Modification timestamp
  • content.hash.sha256 - Content hash (when computed)

Imported facts come from external tools via the enrichment pipeline:

  • EXIF metadata: content.Make, content.Model, content.DateTimeOriginal
  • Geolocation: content.geo.city, content.geo.country
  • Media info: content.mime, content.duration
  • Any custom key-value pairs you choose to import

Namespaces

Facts are namespaced:

  • source.* - Facts about the file on disk (path, size, timestamps)
  • content.* - Facts about the content itself (stored on objects when hashed)

When querying, the content. prefix is optional: --where 'Make=Apple' is equivalent to --where 'content.Make=Apple'.

Value Types

Canon stores facts as:

  • Text: Strings like "Apple" or "image/jpeg"
  • Numbers: Integers or decimals like 1024 or 3.14
  • Timestamps: Unix timestamps, enabling date modifiers like |year and |month

Type hints can be provided during import to ensure correct parsing. See Enriching for details.