Function
| Arg | Description | Type |
|---|---|---|
| message | Message to log. | string (required) |
| dedup | Suppress same message in this many seconds (default 60 sec). | int64 |
| args | An array of elements to apply into the format string. | Any |
| level | Level to log at (DEFAULT, WARN, ERROR, INFO). | string |
Log the message and return TRUE.
The message will be logged into the query log stream (Viewable in
the Logs tab). The message parameter represents a format string
that will be expanded using the args parameter list if needed.
Since log() always returns TRUE it is easy to use in a WHERE
clause as a form of debugging (It is basically equivalent to the
print statement of other languages).
SELECT * FROM glob(...)
WHERE log(message="Value of OSPath is %v", args=OSPath)
Log messages will be deduped according to the dedup
parameter - each distinct format string will not be emitted more
frequently than the dedup parameter (by default 60 seconds).
This makes it safe to use log() frequently without overflowing
the logs stream.
SELECT * FROM range(end=_value)
WHERE log(message="Value is %v", args=_value)
Will only emit a single message due to the format string being deduped.
This property makes it useful to add progress logging to long running artifacts. The logs will be emitted every minute.
SELECT * FROM glob(...)
WHERE log(message="Processing file %v", args=OSPath)