update

Update files or directories imported from external DVC repositories or URLs, and the corresponding import .dvc files.

Synopsis

usage: dvc update [-h] [-q | -v] [-R] [--rev <commit>]
                  [--to-remote] [-r <name>]
                  [--no-download] [-j <number>]
                  targets [targets ...]

positional arguments:
  targets      Import .dvc files to update. Using -R, directories
               to search for .dvc files can also be given.

Description

After creating import stages (.dvc files) with dvc import, dvc import-url, or dvc import-db, the data source can change. Use dvc update to bring these imported files or directories up to date.

To indicate which import stages to update, we can specify the corresponding .dvc file targets as command arguments.

Note that import stages are considered always frozen, meaning that if you run dvc repro, they won't be updated. dvc update is the only command that can update them.

dvc update without flags will not have an effect on import stages that are fixed to a commit hash (rev field in the .dvc file). Use the --rev option to update an imported artifact to a different revision.

$ dvc update --rev master

Options

--rev <version> - commit hash, branch or tag name, etc. (any Git revision) of the repository to update the file or directory from. The latest commit (in the default branch) is used by default.

For data obtained with dvc import-url --version-aware, this option can be used to specify an object version ID. By default, the current version from cloud storage will be used.

Changes the rev field in the import .dvc files.
-R, --recursive - determines the files to update by searching each target directory and its subdirectories for import .dvc files to inspect. If there are no directories among the targets, this option has no effect.
--no-download - Update data checksums in the .dvc file (md5, etag, or checksum fields) without actually downloading the latest data. See dvc import-url --no-download or dvc import --no-download for more context. Cannot be used with --to-remote.
--to-remote - update a .dvc file created with dvc import-url and transfer the data directly to remote storage (the default one unless one is specified with -r) without saving it locally. Use dvc pull to get the data locally.
-r <name>, --remote <name> - name of the dvc remote (can only be used with --to-remote).
-j <number>, --jobs <number> - parallelism level for DVC to download data from the source. The default value is 4 * cpu_count(). Using more jobs may speed up the operation.
-h, --help - prints the usage/help message, and exit.
-q, --quiet - do not write anything to standard output. Exit with 0 if no problems arise, otherwise 1.
-v, --verbose - displays detailed tracing information.

Example

Let's first import a data artifact from our get started example repo:

$ dvc import git@github.com:iterative/example-get-started model.pkl
Importing 'model.pkl (git@github.com:iterative/example-get-started)'
-> 'model.pkl'

As DVC mentions, the import stage (.dvc file) model.pkl.dvc is created. This stage is frozen by default though, so to reproduce it, we would need to run dvc unfreeze on it first, then dvc repro (and dvc freeze again). Let's just run dvc update on it instead:

$ dvc update model.pkl.dvc
Output 'model.pkl' didn't change. Skipping saving.
Saving information to 'model.pkl.dvc'.

This time nothing has changed, since the source project is rather stable.

Note that dvc update updates the rev_lock field of the corresponding .dvc file (when there are changes to bring in).

Example: Updating fixed revisions to a different version

See also Importing and updating fixed revisions.

Let's import a model from a specific version of our get started example repo first:

$ dvc import --rev baseline-experiment \
            git@github.com:iterative/example-get-started \
            model.pkl
Importing 'model.pkl (git@github.com:iterative/example-get-started)'
-> 'model.pkl'

After this, the import stage (.dvc file) model.pkl.dvc is created. Let's try to run dvc update on this file and see what happens.

$ dvc update model.pkl.dvc

There was no output at all, meaning, the model.pkl file was not updated. This is because we tied the import stage to a rev that hasn't changed (i.e.baseline-experiment tag points to a specific Git commit). Therefore, it was not updated.

Let's try to update the model to a different version:

$ dvc update --rev bigrams-experiment model.pkl.dvc
Importing 'model.pkl (git@github.com:iterative/example-get-started)'
-> 'model.pkl'