Simple Oracle query

Question

Hello there, I need help with a query. I have a table like this:
CREATE TABLE ROZNICE
ID NUMBER(12) PK,
IDOBIEKTU NUMBER(12),
DATAWER DATE NOT NULL,
DATAARCH DATE
And I'd like to get all rows that have DATAWER >= SYSDATE or DATAARCH >= SYSDATE, and also get allrows that grouped by IDOBIEKTU has DATAWER equal to last row before SYSDATE e.g. DATAWER < SYSDATE.
All rows that have DATAWER >= SYSDATE && DATAARCH >= SYSDATE and last one (for the same IDOBIEKTU) with DATAWER <= SYSDATE.
I'm trying to do this:
SELECT
FROM
ROZNICE
WHERE
DATAWER >= SYSDATE OR
DATAARCH >= SYSDATE OR
(IDOBIEKTU, DATAWER) IN (SELECT
IDOBIEKTU,
MAX(DATAWER)
FROM
ROZNICE
WHERE
DATAWER < SYSDATE
GROUP BY
IDOBIEKTU
I takes quite a long time to execute this on 20 000 rows table. IDOBIEKTU and of course ID are indexed.
Maybe some analytic fuctions ???

Answer 1

Ok, my mistake, I don't need subquery, what I need is an union:
SELECT
FROM
roznice
WHERE
datawer >= SYSDATE OR
dataarch >= SYSDATE
UNION
SELECT
id,
idobiektu,
datawer,
dataarch
FROM
SELECT
id,
idobiektu,
datawer,
dataarch,
MAX(DATAWER) OVER (PARTITION BY IDOBIEKTU) as maxdatawer
FROM
roznice
WHERE
datawer < SYSDATE
WHERE
datawer = maxdatawer