rewrite query replacing not in - sql

Question

I want to re-write the below query in a way to remove NOT IN is that possible ?
select * from TRX_T TT, TRX_SUB TS
where TT.CODE=TS.CODE
and TT.SUBID= TS.ID
and TS.VALUE=1
and TS.CODE=1
AND TS.ID=17
AND TT.STATUS NOT IN('T','R','C')
If the status was IN I would then use union all
The reason I want to re-write because the below oracle recommendation.
The predicate "TT"."STATUS"<>'C' used at line ID 5 of the execution
plan contains an expression on indexed column "STATUS". This
expression prevents the optimizer from efficiently using indices on
table TT.
Number of Distinct values
T 264
C 5489709
D 2987
J 924
L 529430
R 39382
S 5449
The index on TRX_T is like this: (CODE,SUBID,TYPE,STATUS,NO_SL)

Answer 1

If you want to tune a query you need to understand your data model and your data. The optimiser says it cannot efficiently use an index on TRX_T. Let's look at that compound index:
CODE : used in join criteria
SUBID : used in join criteria
TYPE : not used
STATUS : could be used as filter ?
NO_SL : not used
Your query uses three of the five indexed columns. But because you have a NOT IN expression on STATUS the optimiser doesn't use the index to evaluate the filter. So it reads every record in TRX_T which matches a record in TRX_SUB and evaluates the filter on the table.
Perhaps if you expressed the condition positively as TT.STATUS IN ('D','J','L', 'S') then the optimizer might be able to use a SKIP SCAN to evaluate the filter on the index.
However, the index usage would be more efficient if the TRX_T.TYPE were used as filter ( or if the order of the index columns were re-arranged to have STATUS before TYPE but don't do this as it might destabilise other queries).
Another option would be to rewrite the expression as a NOT IN subquery (if you have no null values in (TRX_T.CODE, TRX_T.SUBID) otherwise as a NOT EXISTS subquery):
select * from TRX_T TT, TRX_SUB TS
where TT.CODE=TS.CODE
and TT.SUBID= TS.ID
and TS.VALUE=1
and TS.CODE=1
AND TS.ID=17
AND (TT.CODE, TT.SUBID) NOT IN
(select x.CODE, x.SUBID
from trx_t x
where x.status in ('T','R','C')
)
However, the number of TRX_T records which have STATUS values in that list is very large - they are the majority of your table - so evaluating that subquery might well be more expensive than what you have at the moment.
Please note, the usual caveats apply. Tuning queries on StackOverflow is a mug's game. Too much information is missing (data volumes, skew, other indexes, explain plans, etc) for us to to do anything other than guess.

Answer 2

use explicit join and not in could be replaced by below way
select * from TRX_T TT
join TRX_SUB TS
on TT.CODE=TS.CODE and TT.SUBID= TS.ID
where TS.VALUE=1
and TS.CODE=1
AND TS.ID=17
and not exists
( select 1 from TRX_T t1 where t1.CODE=TT.code
and (t1.STATUS ='T' OR t1.STATUS='R' or t1.STATUS='C')
)

Answer 3

You can try using left join and filter out TT2.status is null so it will give you those records which are not in ('T','R','C')
select * from TRX_T TT
join TRX_SUB TS on TT.CODE=TS.CODE and TT.SUBID= TS.ID
left join (select * from TRX_T where STATUS in ('T','R','C')) TT2 on
TT.CODE=TT2.CODE and TT.SUBID= TT2.SUBID
where TS.VALUE=1 and TS.CODE=1 AND TS.ID=17 and TT2.status is null

Answer 4

You can use minus set operator as
select *
from TRX_T TT
join TRX_SUB TS
on ( TT.CODE = TS.CODE
and TT.SUBID = TS.ID )
where TS.VALUE = 1
and TS.CODE = 1
and TS.ID = 17
minus
select *
from TRX_T TT
join TRX_SUB TS
on ( TT.CODE = TS.CODE
and TT.SUBID = TS.ID )
where TS.VALUE = 1
and TS.CODE = 1
and TS.ID = 17
and TT.STATUS in ('T', 'R', 'C');
P.S. Yes, Not in is mostly problematic from the performance view, and as a side not using nvl function shouldn't be forgotten when using Not in.

Answer 5

Try the below, you can use 'except':
SELECT *
FROM trx_t TT,
trx_sub TS
WHERE TT.code = TS.code
AND TT.subid = TS.id
AND TS.value = 1
AND TS.code = 1
AND TS.id = 17
EXCEPT
SELECT *
FROM trx_t TT,
trx_sub TS
WHERE TT.status = 'T'
OR TT.status = 'R'
OR TT.status = 'C'