Version 10.0.0
Metadata (Architecture Guide)
Data StructuresSource Location

Metadata in WiredTiger is stored as a table in the "WiredTiger.wt" file. The table's key is a uri string, and the value is its complete configuration string. The configuration itself is a list of key/value pairs in string form. The configuration's keys are dependent on the type of uri. Thus, a metadata entry with a uri key beginning with "table:" will be a configuration string having configuration entries like key_format and value_format to describe the data encoding for the uri. A metadata key beginning with "file:" will have a different set of configuration entries associated with it.

A caller of WiredTiger can use WT_SESSION::open_cursor with a uri equal to "meta:" to read the metadata. Using this interface, metadata can only be queried, not changed. Changes to the metadata are affected by API calls such as WT_SESSION::create, WT_SESSION::drop, WT_SESSION::rename.