Metadata

Storing and reading experiment-wide key/value metadata in the metadata table.

Store and read experiment metadata

Use metadata store/load/show to keep experiment-wide key/value notes in the metadata table.

APIs: metadata:store, metadata:load, metadata:show

The metadata table holds experiment-wide key/value pairs — a single place for facts about the whole experiment (a dataset version, a paper’s figure label, a git revision) rather than about one invocation. Store, read one back, and dump them all:

$ ./exp.sh metadata store --key dataset --value cifar-10
$ ./exp.sh metadata load --key dataset
cifar-10
$ ./exp.sh metadata show
key      value
-------  --------
dataset  cifar-10

Storing an existing key fails on the table’s uniqueness constraint; pass --force to overwrite it:

$ ./exp.sh metadata store --force --key dataset --value cifar-100

metadata load prints just the value (empty when the key is absent), which makes it easy to capture in a script: rev="$(./exp.sh metadata load --key dataset)". metadata show also lists knit’s own bootstrap metadata — the __project__, __scheduler__, __profile_json__, and similar double-underscore keys frozen at bootstrap — alongside your own. All three commands need a bootstrapped experiment.