Hi Amrish,
You could try splitting the IN clause using UNION ALL as follows:
SELECT DISTINCT RAW DocNum
FROM (
SELECT DocNum FROM tranData WHERE DocNum = "10112746" AND `$MdfdTmstmp` BETWEEN "2022-06-15T00:00:00" AND "2022-06-17T23:59:59"
UNION ALL
SELECT DocNum FROM tranData WHERE DocNum = "12345" AND `$MdfdTmstmp` BETWEEN "2022-06-15T00:00:00" AND "2022-06-17T23:59:59"
) t
Alternatively, try dropping your index and create one only on $MdfdTmstmp field
create index tran_ts_ix on tranData(
$MdfdTmstmp:STRING);
Then your original query should use that index for the BETWEEN predicate:
SELECT DISTINCT RAW DocNum
FROM tranData
WHERE DocNum IN ["10112746", "10112747"]
AND `$MdfdTmstmp` BETWEEN "2022-06-15T00:00:00" AND "2022-06-17T23:59:59"
The LET clause problem requires further investigation on our side.