oracle sql get transactions between the period - sql

Question

I have 3 tables in oracle sql namely investor, share and transaction.
I am trying to get new investors invested in any shares for a certain period. As they are the new investor, there should not be a transaction in the transaction table for that investor against that share prior to the search period.
For the transaction table with the following records:
Id TranDt InvCode ShareCode
1 2020-01-01 00:00:00.000 inv1 S1
2 2019-04-01 00:00:00.000 inv1 S1
3 2020-04-01 00:00:00.000 inv1 S1
4 2021-03-06 11:50:20.560 inv2 S2
5 2020-04-01 00:00:00.000 inv3 S1
For the search period between 2020-01-01 and 2020-05-01, I should get the output as
5 2020-04-01 00:00:00.000 inv3 S1
Though there are transactions for inv1 in the table for that period, there is also a transaction prior to the search period, so that shouldn't be included as it's not considered as new investor within the search period.
Below query is working but it's really taking ages to return the results calling from c# code leading to timeout issues. Is there anything we can do to refine to get the results quicker?
WITH
INVESTORS AS
(
SELECT I.INVCODE FROM INVESTOR I WHERE I.CLOSED IS NULL)
),
SHARES AS
(
SELECT S.SHARECODE FROM SHARE S WHERE S.DORMANT IS NULL))
),
SHARES_IN_PERIOD AS
(
SELECT DISTINCT
T.INVCODE,
T.SHARECODE,
T.TYPE
FROM TRANSACTION T
JOIN INVESTORS I ON T.INVCODE = I.INVCODE
JOIN SHARES S ON T.SHARECODE = S.SHARECODE
WHERE T.TRANDT >= :startDate AND T.TRANDT <= :endDate
),
PREVIOUS_SHARES AS
(
SELECT DISTINCT
T.INVCODE,
T.SHARECODE,
T.TYPE
FROM TRANSACTION T
JOIN INVESTORS I ON T.INVCODE = I.INVCODE
JOIN SHARES S ON T.TRSTCODE = S.TRSTCODE
WHERE T.TRANDT < :startDate
)
SELECT
DISTINCT
SP.INVCODE AS InvestorCode,
SP.SHARECODE AS ShareCode,
SP.TYPE AS ShareType
FROM SHARES_IN_PERIOD SP
WHERE (SP.INVCODE, SP.SHARECODE, SP.TYPE) NOT IN
(
SELECT
PS.INVCODE,
PS.SHARECODE,
PS.TYPE
FROM PREVIOUS_SHARES PS
)
With the suggestion given by #Gordon Linoff, I tried following options (for all the shares I need) but they are taking long time too. Transaction table is over 32 million rows.
1.
WITH
SHARES AS
(
SELECT S.SHARECODE FROM SHARE S WHERE S.DORMANT IS NULL))
)
select t.invcode, t.sharecode, t.type
from (select t.*,
row_number() over (partition by invcode, sharecode, type order by trandt)
as seqnum
from transactions t
) t
join shares s on s.sharecode = t.sharecode
where seqnum = 1 and
t.trandt >= date '2020-01-01' and
t.trandt < date '2020-05-01';
WITH
INVESTORS AS
(
SELECT I.INVCODE FROM INVESTOR I WHERE I.CLOSED IS NULL)
),
SHARES AS
(
SELECT S.SHARECODE FROM SHARE S WHERE S.DORMANT IS NULL))
)
select t.invcode, t.sharecode, t.type
from (select t.*,
row_number() over (partition by invcode, sharecode, type order by trandt)
as seqnum
from transactions t
) t
join investors i on i.invcode = t.invcode
join shares s on s.sharecode = t.sharecode
where seqnum = 1 and
t.trandt >= date '2020-01-01' and
t.trandt < date '2020-05-01';
select t.invcode, t.sharecode, t.type
from (select t.*,
row_number() over (partition by invcode, sharecode, type order by trandt)
as seqnum
from transactions t
) t
where seqnum = 1 and
t.sharecode IN (SELECT S.SHARECODE FROM SHARE S WHERE S.DORMANT IS NULL)))
and
t.trandt >= date '2020-01-01' and
t.trandt < date '2020-05-01';

Answer 1

If you want to know if the first record in transactions for a share is during a period, you can use window functions:
select t.*
from (select t.*,
row_number() over (partition by invcode, sharecode order by trandt) as seqnum
from transactions t
) t
where seqnum = 1 and
t.sharecode = :sharecode and
t.trandt >= date '2020-01-01' and
t.trandt < date '2020-05-01';
For performance for this code, you want an index on transactions(invcode, sharecode, trandate).