Oracle SQL - selective filtering causes cartesian - sql

Oracle 12.2
I have a SQL statement that is causing me issues. I am retrieving data from a table called BURNDOWN. If the user is an admin, they get to see all the data. If the user is NOT an admin, they are restricted to what they can see, based on some join conditions.
The issue I am running into is when the user is an ADMIN, I don’t need the other tables… subsequently, the JOIN condition is not relevant, so Oracle is deciding to do a cartesian join across everything…
How do I get around this so that is the user is an Admin, I only look at one table, else I look at all tables and include the join condition?
The example SQL is a contrived example, but it shows the issue.
Select
BURNDOWN.NAME,
BURNDOWN.ADDRESS,
BURNDOWN.STATE
from BURNDOWN, FILTER_A, FILTER_B, FILTER_C
Where
(
:ISAdmin = 1
Or
(
BURNDOWN.x=FILTER_A.x and
FILTER_A.y=FILTER_B.y and
FILTER_B.z=FILTER_C.z and
FILTER_C.user = :ThisUser
)
)

Use an EXISTS to see if the data exists in the FILTER tables without joining them in to the results.
select bd.*
from burndown bd
where ( :isadmin = 1 or
exists ( select 1
from filter_a a
inner join filter_b b on b.y = a.y
inner join filter_c c on c.z = b.z
where a.x = bd.x
and c.user = :ThisUser )
)

Presumably, you want:
select bd.*
from burndown bd
where :ISAdmin = 1 or
(exists (select 1 from FILTER_A a where bd.x = a.x) or
exists (select 1 from FILTER_B b where bd.y = b.y) or
exists (select 1 from FILTER_C c where bd.z = c.z)
);

Related

Trying to update a field conditionally in SQL Stored Procedure

I have a procedure that populates two sets of application information into the same fields. First the fields are filled out with applicable accounts from group "A" and then the same process happens for group "B" accounts.
Most of the group B fields are filled in by a insert/select statement. However, the query to select "account number" is a little more complex and that is in an UPDATE statement. I will paste the code below but I cannot get it to properly update the rows (for group B) with account numbers, despite the fact the query works on its own outside the procedure (essentially, the account numbers do exist).
Any idea why? I tried adding a case statement to single out group B rows (the where clause is hardcoded for group B... e.g. clfcode = 3) but that didn't work. Let me know if you need more information. I haven't much experience with update statements in stored procedures.
update src
set account_key = case when src.clfcode = 3 and src.branch_key = 12 then a.account_key else src.account_key end
from #src_table src
inner join SDFDW_Landing.cu.FICS_ms_Investor_Loan l
on l.loan_id = src.application_number
left join dm.dim_product p
on p.product_key = src.product_key
left join (
Select Distinct t.PARENTACCOUNT, t.USERCHAR1 as loan_id
from SDFDW_Landing.dbo.tracking t
where t.TYPE = 1
and t.ProcessDate = #v_max_last_processed_date
and t.USERCHAR1 is not null
) t on t.loan_id = l.loan_id
left join dm.dim_account a
on t.PARENTACCOUNT = a.account_nkey
WHERE p.bdw_report_category = 'Mortgage'
and l.processdate = #v_max_last_processed_date
The join on a subquery might cause the issue. You could try to replace it with an apply and see if that helps.
update
src
set
account_key =
case
when
src.clfcode = 3
and src.branch_key = 12
then
a.account_key
else
src.account_key
end
from
#src_table src
inner join
SDFDW_Landing.cu.FICS_ms_Investor_Loan l
on l.loan_id = src.application_number
left join
dm.dim_product p
on p.product_key = src.product_key
outer apply (
Select
acc.*
from
dm.dim_account acc
inner join
SDFDW_Landing.dbo.tracking t
on acc.account_nkey = t.parentaccount
where
t.TYPE = 1
and t.ProcessDate = #v_max_last_processed_date
and t.USERCHAR1 is not null
and t.loan_id = l.loan_id
) a
WHERE
p.bdw_report_category = 'Mortgage'
and l.processdate = #v_max_last_processed_date
alternatively since you are already within a stored procedure, I'd populate a temp table with the data from your subquery and simply join on that temp table from your update statement.

SELECT NOT IN with multiple columns in subquery

Regarding the statement below, sltrxid can exist as both ardoccrid and ardocdbid. I'm wanting to know how to include both in the NOT IN subquery.
SELECT *
FROM glsltransaction A
INNER JOIN cocustomer B ON A.acctid = B.customerid
WHERE sltrxstate = 4
AND araccttype = 1
AND sltrxid NOT IN(
SELECT ardoccrid,ardocdbid
FROM arapplyitem)
I would recommend not exists:
SELECT *
FROM glsltransaction t
INNER JOIN cocustomer c ON c.customerid = t.acctid
WHERE
??.sltrxstate = 4
AND ??.araccttype = 1
AND NOT EXISTS (
SELECT 1
FROM arapplyitem a
WHERE ??.sltrxid IN (a.ardoccrid, a.ardocdbid)
)
Note that I changed the table aliases to things that are more meaningful. I would strongly recommend prefixing the column names with the table they belong to, so the query is unambiguous - in absence of any indication, I represented this as ?? in the query.
IN sometimes optimize poorly. There are situations where two subqueries are more efficient:
SELECT *
FROM glsltransaction t
INNER JOIN cocustomer c ON c.customerid = t.acctid
WHERE
??.sltrxstate = 4
AND ??.araccttype = 1
AND NOT EXISTS (
SELECT 1
FROM arapplyitem a
WHERE ??.sltrxid = a.ardoccrid
)
AND NOT EXISTS (
SELECT 1
FROM arapplyitem a
WHERE ??.sltrxid = a.ardocdbid
)

Oracle SQL XOR condition with > 14 tables

I have a question on sql desgin.
Context:
I have a table called t_master and 13 other tables (lets call them a,b,c... for simplicity) where it needs to compared.
Logic:
t_master will be compared to table 'a' where t_master.gen_val =
a.value.
If record exist in t_master, retrieve t_master record, else retrieve 'a' record.
I do not need to retrieve the records if it exists in both tables (t_master and a) - XOR condition
Repeat this comparison with the remaining 12 tables.
I have some idea on doing this, using WITH to subquery the non-master tables (a,b,c...) first with their respective WHERE clause.
Then use XOR statement to retrieve the records.
Something like
WITH a AS (SELECT ...),
b AS (SELECT ...)
SELECT field1,field2...
FROM t_master FULL OUTER JOIN a FULL OUTER JOIN b FULL OUTER JOIN c...
ON t_master.gen_value = a.value
WHERE ((field1 = x OR field2 = y ) AND NOT (field1 = x AND field2 = y))
AND ....
.
.
.
.
Seeing that I have 13 tables that I need to full outer join, is there a better way/design to handle this?
Otherwise I would have at least 2*13 lines of WHERE clause which I'm not sure if that will have impact on the performance as t_master is sort of a log table.
**Assume I cant change any schema.
Currently I'm not sure if this SQL will working correctly yet, so I'm hoping someone can guide me in the right direction regarding this.
update from used_by_already's suggestion:
This is what I'm trying to do (comparison between 2 tables first, before I add more, but I am unable to get values from ATP_R.TBL_HI_HDR HI_HDR as it is in the NOT EXISTS subquery.
How do i overcome this?
SELECT LOG_REPO.UNIQ_ID,
LOG_REPO.REQUEST_PAYLOAD,
LOG_REPO.GEN_VAL,
LOG_REPO.CREATED_BY,
TO_CHAR(LOG_REPO.CREATED_DT,'DD/MM/YYYY') AS CREATED_DT,
HI_HDR.HI_NO R_VALUE,
HI_HDR.CREATED_BY R_CREATED_BY,
TO_CHAR(HI_HDR.CREATED_DT,'DD/MM/YYYY') AS R_CREATED_DT
FROM ATP_COMMON.VW_CMN_LOG_GEN_REPO LOG_REPO JOIN ATP_R.TBL_HI_HDR HI_HDR ON LOG_REPO.GEN_VAL = HI_HDR.HI_NO
WHERE NOT EXISTS
(SELECT NULL
FROM ATP_R.TBL_HI_HDR HI_HDR
WHERE LOG_REPO.GEN_VAL = HI_HDR.HI_NO
)
UNION ALL
SELECT LOG_REPO.UNIQ_ID,
LOG_REPO.REQUEST_PAYLOAD,
LOG_REPO.GEN_VAL,
LOG_REPO.CREATED_BY,
TO_CHAR(LOG_REPO.CREATED_DT,'DD/MM/YYYY') AS CREATED_DT,
HI_HDR.HI_NO R_VALUE,
HI_HDR.CREATED_BY R_CREATED_BY,
TO_CHAR(HI_HDR.CREATED_DT,'DD/MM/YYYY') AS R_CREATED_DT
FROM ATP_R.TBL_HI_HDR HI_HDR JOIN ATP_COMMON.VW_CMN_LOG_GEN_REPO LOG_REPO ON HI_HDR.HI_NO = LOG_REPO.GEN_VAL
WHERE NOT EXISTS
(SELECT NULL
FROM ATP_COMMON.VW_CMN_LOG_GEN_REPO LOG_REPO
WHERE HI_HDR.HI_NO = LOG_REPO.GEN_VAL
)
Full outer joins used to exclude all matching rows can be an expensive query. You don't supply much detail, but perhaps using NOT EXISTS would be simpler and maybe it will produce a better explain plan. Something along these lines.
select
cola,colb,colc
from t_master m
where not exists (
select null from a where m.keycol = a.fk_to_m
)
and not exists (
select null from b where m.keycol = b.fk_to_m
)
and not exists (
select null from c where m.keycol = c.fk_to_m
)
union all
select
cola,colb,colc from a
where not exists (
select null from t_master m where a.fk_to_m = m.keycol
)
union all
select
cola,colb,colc from b
where not exists (
select null from t_master m where b.fk_to_m = m.keycol
)
union all
select
cola,colb,colc from c
where not exists (
select null from t_master m where c.fk_to_m = m.keycol
)
You could union the 13 a,b,c ... tables to simplify the coding, but that may not perform so well.

Performance Issue in Left outer join Sql server

In my project I need find difference task based on old and new revision in the same table.
id | task | latest_Rev
1 A N
1 B N
2 C Y
2 A Y
2 B Y
Expected Result:
id | task | latest_Rev
2 C Y
So I tried following query
Select new.*
from Rev_tmp nw with (nolock)
left outer
join rev_tmp old with (nolock)
on nw.id -1 = old.id
and nw.task = old.task
and nw.latest_rev = 'y'
where old.task is null
when my table have more than 20k records this query takes more time?
How to reduce the time?
In my company don't allow to use subquery
Use LAG function to remove the self join
SELECT *
FROM (SELECT *,
CASE WHEN latest_Rev = 'y' THEN Lag(latest_Rev) OVER(partition BY task ORDER BY id) ELSE NULL END AS prev_rev
FROM Rev_tmp) a
WHERE prev_rev IS NULL
My answer assumes
You can't change the indexes
You can't use subqueries
All fields are indexed separately
If you look at the query, the only value that really reduces the resultset is latest_rev='Y'. If you were to eliminate that condition, you'd definitely get a table scan. So we want that condition to be evaluated using an index. Unfortunately a field that just values 'Y' and 'N' is likely to be ignored because it will have terrible selectivity. You might get better performance if you coax SQL Server into using it anyway. If the index on latest_rev is called idx_latest_rev then try this:
Set transaction isolated level read uncommitted
Select new.*
from Rev_tmp nw with (index(idx_latest_rev))
left outer
join rev_tmp old
on nw.id -1 = old.id
and nw.task = old.task
where old.task is null
and nw.latest_rev = 'y'
latest_Rev should be a Bit type (boolean equivalent), i better for performance (Detail here)
May be can you add index on id, task
, latest_Rev columns
You can try this query (replace left outer by not exists)
Select *
from Rev_tmp nw
where nw.latest_rev = 'y' and not exists
(
select * from rev_tmp old
where nw.id -1 = old.id and nw.task = old.task
)

How can I join on multiple columns within the same table that contain the same type of info?

I am currently joining two tables based on Claim_Number and Customer_Number.
SELECT
A.*,
B.*,
FROM Company.dbo.Company_Master AS A
LEFT JOIN Company.dbp.Compound_Info AS B ON A.Claim_Number = B.Claim_Number AND A.Customer_Number = B.Customer_Number
WHERE A.Filled_YearMonth = '201312' AND A.Compound_Ind = 'Y'
This returns exactly the data I'm looking for. The problem is that I now need to join to another table to get information based on a Product_ID. This would be easy if there was only one Product_ID in the Compound_Info table for each record. However, there are 10. So basically I need to SELECT 10 additional columns for Product_Name based on each of those Product_ID's that are being selected already. How can do that? This is what I was thinking in my head, but is not working right.
SELECT
A.*,
B.*,
PD_Info_1.Product_Name,
PD_Info_2.Product_Name,
....etc {Up to 10 Product Names}
FROM Company.dbo.Company_Master AS A
LEFT JOIN Company.dbo.Compound_Info AS B ON A.Claim_Number = B.Claim_Number AND A.Customer_Number = B.Customer_Number
LEFT JOIN Company.dbo.Product_Info AS PD_Info_1 ON B.Product_ID_1 = PD_Info_1.Product_ID
LEFT JOIN Company.dbo.Product_Info AS PD_Info_2 ON B.Product_ID_2 = PD_Info_2.Product_ID
.... {Up to 10 LEFT JOIN's}
WHERE A.Filled_YearMonth = '201312' AND A.Compound_Ind = 'Y'
This query not only doesn't return the correct results, it also takes forever to run. My actual SQL is a lot longer and I've changed table names, etc but I hope that you can get the idea. If it matters, I will be creating a view based on this query.
Please advise on how to select multiple columns from the same table correctly and efficiently. Thanks!
I found put my extra stuff into CTE and add ROW_NUMBER to insure that I get only 1 row that I care about. it would look something like this. I only did for first 2 product info.
WITH PD_Info
AS ( SELECT Product_ID
,Product_Name
,Effective_Date
,ROW_NUMBER() OVER ( PARTITION BY Product_ID, Product_Name ORDER BY Effective_Date DESC ) AS RowNum
FROM Company.dbo.Product_Info)
SELECT A.*
,B.*
,PD_Info_1.Product_Name
,PD_Info_2.Product_Name
FROM Company.dbo.Company_Master AS A
LEFT JOIN Company.dbo.Compound_Info AS B
ON A.Claim_Number = B.Claim_Number
AND A.Customer_Number = B.Customer_Number
LEFT JOIN PD_Info AS PD_Info_1
ON B.Product_ID_1 = PD_Info_1.Product_ID
AND B.Fill_Date >= PD_Info_1.Effective_Date
AND PD_Info_2.RowNum = 1
LEFT JOIN PD_Info AS PD_Info_2
ON B.Product_ID_2 = PD_Info_2.Product_ID
AND B.Fill_Date >= PD_Info_2.Effective_Date
AND PD_Info_2.RowNum = 1