Row 1:
Column 0,   name: datetime,        type: String, parsed text: "2021-Jan^d1^d2"  ERROR: Line feed found where delimiter (,) is expected. It's like your file has less columns than expected.                                 
And if your file have right number of columns, maybe it have unescaped quotes in value        


А

Code: 49, e.displayText() = DB::Exception: There is no checkpoint (version 20.1.2.4 (official build)) 

find . -type f -name 'j.log' | while read f; do
  curl "http://localhost:8123
/?query=INSERT%20INTO%20mydb%20FORMAT%20CustomSeparated%20SETTINGS%20format_custom_escaping_rule%3D%27CSV%27%2C%20format_custom_field_delimiter%20%3D%20%27%5E%27" --data-binary "@${f}"
done

set max_threads = 6;
set min_insert_block_size_rows=200000;

create ttt as prototype_table

engine=Log

zcat file | clickhouse-client -q"insert into ttt format CSV"

[hostname] 2021.01.13 15:01:57.683883 [ 2607564 ] {f1e730ce-c8f9-429c-a8b5-d957fdc1f27f} <Information> executeQuery: Read 1624753 rows, 1.35 GiB in 28.547938887 sec., 56913 rows/sec., 48.38 MiB/sec.
[hostname] 2021.01.13 15:01:57.684423 [ 2607564 ] {f1e730ce-c8f9-429c-a8b5-d957fdc1f27f} <Debug> MemoryTracker: Peak memory usage (for query): 3.32 GiB.