FROM (repository[:tag])/(MOUNT handler conn_string handler_options) IMPORT table1/{query1} [AS table1_alias], [table2/{query2}...]

Uses the sgr import command to import one or more tables from either a local repository, a remote one, or an FDW-mounted database.

Optionally, the table name can be replaced with a SELECT query in curly braces that will get executed against the source repository in order to create a table. This will be stored as a snapshot. For example:

FROM internal_data:latest IMPORT {SELECT name, age FROM staff WHERE is_restricted = FALSE} AS visible_staff

Will create a new table that contains non-restricted staff names and ages in internal_data.staff without including any other entries in the table history.

The SQL query can only contain one statement and has to be a SELECT query that doesn't reference any schema-qualified tables.

In the case of imports from FDW, the commit hash produced by this command is random. Otherwise, the commit hash will be a combination of the current OUTPUT hash, the hash of the source repository and the hashes of the names (or source SQL queries) and aliases of all imported tables.

This means that the layer is invalidated if there's a change to the remote repository, a different table is imported, named differently or a different query is used to create a table.