@KS LAU​ :

Answer 1:

Yes, you are correct. The local file system refers to the file system on the Spark driver node. It is the file system where the Spark application is running and where the application can read and write files.

Answer 2:

Yes, you can read a file directly from DBFS. You can use the Databricks File System (DBFS) API to read files from DBFS. You can also use the dbutils.fs.head command to preview the first n bytes of a file in DBFS. Here is an example:

dbfs_file = "/mnt/data/myfile.csv"
dbutils.fs.head(dbfs_file, 100)

This will preview the first 100 bytes of the file /mnt/data/myfile.csv in DBFS.

Answer 3:

To copy a file from DBFS to the local file system, you can use the dbutils.fs.cp command with the

file:/ schema to specify the local file system. Here is an example:

dbfs_file = "/mnt/data/myfile.csv"
local_file = "file:///tmp/myfile.csv"
dbutils.fs.cp(dbfs_file, local_file)

This will copy the file /mnt/data/myfile.csv in DBFS to /tmp/myfile.csv in the local file system. Note that you need to have write permission on the local file system to write the file. Also, make sure that the file:/// schema is used to specify the local file system.