DuckDB: Query S3 Access Logs

parse_s3_access_logs.sql

/* 
  Usage: you'll want to search for the strings <bucket> and <prefix>, and insert the S3 bucket where your access
  logs are being delivered. Use (or delete) <prefix> to filter to a subset of your logs.
*/

 
/*
  These commented out configuration settings you can either run  yourself in the REPL and source this file using
  `.read parse_s3_access_logs.sql`, or you can uncomment them and supply values for yourself.
*/

-- install https;
-- load https;
-- SET s3_region='us-west-2';
-- SET s3_access_key_id='';
-- SET s3_secret_access_key='';

WITH parsed_logs AS (
    SELECT
        regexp_extract(col1, '^([0-9a-zA-Z]+)\s+([a-z0-9.\-]+)\s+\[([0-9/A-Za-z: +]+)\] ([^ ]+) ([^ ]+) ([^ ]+) ([^ ]+) ([^ ]+) ("[^"]*"|-) ([^ ]+) ([^ ]+) (\d+|-) (\d+|-) (\d+|-) (\d+|-) ("[^"]*"|-) ("[^"]*"|-) (\S+) (\S+) (\S+) (\S+) (\S+) (\S+) (\S+) (\S+) (\S+)(.*)$',
        [
                'bucket_owner', 'bucket', 'timestamp', 'remote_ip', 'request', 'request_id',
                'operation', 's3_key', 'request_uri', 'http_status', 's3_errorcode', 'bytes_sent',
                'object_size', 'total_time', 'turn_around_time', 'referer', 'user_agent',
                'version_id', 'host_id', 'sigver', 'cyphersuite', 'auth_type', 'host_header',
                'tls_version', 'access_point_arn', 'acl_required', 'extra'
        ]) AS log_struct
    FROM
        -- Trick the CSV reader into reading as a single column
        read_csv(
            's3://<bucket>/<prefix>/*',
            columns={'col1': 'VARCHAR'},
            -- Use a *hopefully* nonsensical deliminator, so no ',' chars screw us up
            delim='\0'
        )
)
SELECT
        -- Grab everything from the struct that we want as strings, exclude stuff we'll coersce to diff types
        log_struct.* exclude (timestamp, bytes_sent, object_size, total_time, turn_around_time),
        strptime(log_struct.timestamp, '%d/%b/%Y:%H:%M:%S %z') AS timestamp,
        CASE
                WHEN log_struct.bytes_sent = '-' THEN NULL
                ELSE CAST(log_struct.bytes_sent AS INTEGER)
        END AS bytes_sent,
        CASE
                WHEN log_struct.object_size = '-' THEN NULL
                ELSE CAST(log_struct.object_size AS INTEGER)
        END AS object_size,
        CASE
                WHEN log_struct.total_time = '-' THEN NULL
                ELSE CAST(log_struct.total_time AS INTEGER)
        END AS total_time,
        CASE
                WHEN log_struct.turn_around_time = '-' THEN NULL
                ELSE CAST(log_struct.turn_around_time AS INTEGER)
        END AS turn_around_time
FROM parsed_logs;

Couldn't the integer casting be simplified with try_cast function here? I.e. instead of:

...
CASE
    WHEN log_struct.bytes_sent = '-' THEN NULL
    ELSE CAST(log_struct.bytes_sent AS INTEGER)
END AS bytes_sent,
...

it would look like

...
try_cast(log_struct.bytes_sent AS INTEGER) AS bytes_sent,
try_cast(log_struct.object_size AS INTEGER) AS object_size,
try_cast(log_struct.total_time AS INTEGER) AS total_time,
try_cast(log_struct.turn_around_time AS INTEGER) AS turn_around_time,
...

Sure, go for it!