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From "Nikos R. Katsipoulakis" <nick.kat...@gmail.com>
Subject Additional information on JSON_SUB_SCAN operator and access to query profiles not from the Web UI
Date Wed, 11 Jan 2017 15:37:30 GMT
Hello all,

I am a new user of Apache Drill and I am in the process of better
understanding its internals. To that end, I have two questions, for which I
was unable to find more information online.

First, when I execute an EXPLAIN command for a query that gets its data
from JSON files, I see a physical operator named JSON_SUB_SCAN. What does
that operator exactly do? Is it only used for parsing (extracting) fields
from JSON data? Or does it perform additional processing? As far as I know,
Drill uses Jackson Streaming API for extracting JSON data. Is that still
true? Finally, what is the equivalent operator for CSV files?

Second, I need to access query profiles from a server that is behind a
firewall. Therefore, accessing the URL of that machine on port 8047 is a
headache (since I have to submit a ticket to IT Support). My question is
whether I can access the Query Profiles in any other way? Like from the
sqlline or through log/profile files created while executing queries.

Thank you and Kind Regards,

Nikos R. Katsipoulakis,
Department of Computer Science
University of Pittsburgh

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