I have a SQL Query that comprise of two level sub-select. This is taking too much time.
The Query goes like:
select * from DALDBO.V_COUNTRY_DERIV_SUMMARY_XREF
where calculation_context_key = 130205268077
and DERIV_POSITION_KEY in
(select ctry_risk_derivs_psn_key
from DALDBO.V_COUNTRY_DERIV_PSN
where calculation_context_key = 130111216755
--and ctry_risk_derivs_psn_key = 76296412
and CREDIT_PRODUCT_TYPE = 'SWP OP'
and CALC_OBLIGOR_COUNTRY_OF_ASSETS in
(select ctry_cd
from DALDBO.V_PSN_COUNTRY
where calculation_context_key = 130134216755
--and ctry_risk_derivs_psn_key = 76296412
)
)
These tables are huge! Is there any optimizations available?
Without knowing anything about your table or view definitions, indexing, etc. I would start by looking at the sub-selects and ensuring that they are performing optimally. I would also want to know how many values are being returned by each sub-select as this can impact performance.
How is calculation_context_key used to retrieve rows from V_COUNTRY_DERIV_PSN and V_PSN_COUNTRY? Is it an optimal execution plan?
How is DERIV_POSITION_KEY and CALC_OBLIGOR_COUNTRY_OF_ASSETS used in V_COUNTRY_DERIV_SUMMARY_XREF to retrieve rows? Again, look at the explain plan.
first of all, can you write this query using inner joins (and not subselect) ??
select A.*
from DALDBO.V_COUNTRY_DERIV_SUMMARY_XREF a,
DALDBO.V_COUNTRY_DERIV_PSN b,
DALDBO.V_PSN_COUNTRY c
where calculation_context_key = 130205268077
and a.DERIV_POSITION_KEY = b.ctry_risk_derivs_psn_key
and b.calculation_context_key = 130111216755
--and b.ctry_risk_derivs_psn_key = 76296412
and b.CREDIT_PRODUCT_TYPE = 'SWP OP'
and b.CALC_OBLIGOR_COUNTRY_OF_ASSETS = c.ctry_cd
and c.calculation_context_key = 130134216755
--and c.ctry_risk_derivs_psn_key = 76296412
second, best practice says that when you don't query any data from the tables in the subselect you better of using an EXISTS instead of IN. new versions of oracle does that automatically and actually rewrite the whole thing as an inner join.
last, without any knowledge on you data and of what you are trying to do i would suggest you to try and use views as less as you can - if you can query the underling tables it would be best and you will probably see immediate performance improvement.
Related
We are facing a performance issue while executing a stored procedure. It usually takes between 10-15 minutes to run, but sometimes it takes up to more than 30 minutes to execute.
We captured visualize plan execute files for the Normal run and Long run cases.
By checking the visualized plan we came to know that, one particular Insert block of code takes extra time in the long run. And by checking
"EXPLAIN PLAN FOR SQL PLAN CACHE ENTRY <plan_id> "
the table we found that the order of execution differs in the long run.
This is the block which takes extra time to run sometimes.
INSERT INTO #TMP_DATI_SALDI_LORDI_BASE (
"COD_SCENARIO","COD_PERIODO","COD_CONTO","COD_DEST1","COD_DEST2","COD_DEST3","COD_DEST4","COD_DEST5"
,"IMPORTO","COD_VALUTA","IMPORTO_VALUTA_ORIGINARIA","COD_VALUTA_ORIGINARIA","NOTE"
)
( SELECT
SCEN_P.SCENARIO
,SCEN_P.PERIOD
,ACCOUT_ADJ.ATTRIBUTO1 AS "COD_CONTO"
,DATAS_rev.COD_DEST1
,DATAS_rev.COD_DEST2
,DATAS_rev.COD_DEST3
,__typed_NString__($1, 50)
,'RPT_NON'
,SUM(
CASE WHEN INFO.INCOT = 'FOB' THEN
CASE ACCOUT_rev.ATTRIBUTO1 WHEN 'CalcInsurance' THEN
0
ELSE
DATAS_rev.IMPORTO
END
ELSE
DATAS_rev.IMPORTO
END
* (DATAS_ADJ.IMPORTO - DATAS.IMPORTO)
)
,DATAS_rev.COD_VALUTA
,SUM(
CASE WHEN INFO.INCOT = 'FOB' THEN
CASE ACCOUT_rev.ATTRIBUTO1 WHEN 'CalcInsurance' THEN
0
ELSE
DATAS_rev.IMPORTO_VALUTA_ORIGINARIA
END
ELSE
DATAS_rev.IMPORTO_VALUTA_ORIGINARIA
END
* (DATAS_ADJ.IMPORTO_VALUTA_ORIGINARIA - DATAS.IMPORTO_VALUTA_ORIGINARIA)
)
,DATAS_rev.COD_VALUTA_ORIGINARIA
,'CPM_SP_CACL_FY_E3 Parts Option ADJ'
FROM #TMP_TAGERT_SCEN_P SCEN_P
INNER JOIN #TMP_DATI_SALDI_LORDI_BASE DATAS_rev
ON DATAS_rev.COD_SCENARIO = SCEN_P.SCENARIO
AND DATAS_rev.COD_PERIODO = SCEN_P.PERIOD
AND LEFT(DATAS_rev.COD_DEST3, 1) = 'O'
INNER JOIN CONTO ACCOUT_rev
ON ACCOUT_rev.COD_CONTO = DATAS_rev.COD_CONTO
AND ACCOUT_rev.ATTRIBUTO1 IN ('CalcFOB','CalcInsurance') --FOB,Insurance(Ocean freight is Nothing by Option)
INNER JOIN #DSL DATAS
ON DATAS.COD_SCENARIO = 'LAUNCH'
AND DATAS.COD_PERIODO = 12
AND DATAS.COD_DEST1 = 'NC'
AND DATAS.COD_DEST2 = 'NC'
AND DATAS.COD_DEST3 = 'F001'
AND DATAS.COD_DEST4 = DATAS_rev.COD_DEST4
AND DATAS.COD_DEST5 = 'INP'
INNER JOIN CONTO ACCOUT
ON ACCOUT.COD_CONTO = DATAS.COD_CONTO
AND ACCOUT.ATTRIBUTO2 = 'E3'
INNER JOIN CONTO ACCOUT_ADJ
ON ACCOUT_ADJ.ATTRIBUTO3 = DATAS.COD_CONTO
AND ACCOUT_ADJ.ATTRIBUTO2 = 'HE3'
INNER JOIN #DSL DATAS_ADJ
ON LEFT(DATAS_ADJ.COD_SCENARIO,4) = LEFT(SCEN_P.SCENARIO,4)
AND DATAS_ADJ.COD_PERIODO = 12
AND DATAS_ADJ.COD_DEST1 = DATAS.COD_DEST1
AND DATAS_ADJ.COD_DEST2 = DATAS.COD_DEST2
AND DATAS_ADJ.COD_DEST3 = DATAS.COD_DEST3
AND DATAS_ADJ.COD_DEST4 = DATAS.COD_DEST4
AND DATAS_ADJ.COD_DEST5 = DATAS.COD_DEST5
AND DATAS_ADJ.COD_CONTO = ACCOUT_ADJ.COD_CONTO
LEFT OUTER JOIN #TMP_KDPWT_INCOTERMS INFO
ON INFO.P_CODE = DATAS.COD_DEST4
GROUP BY
SCEN_P.SCENARIO,SCEN_P.PERIOD,ACCOUT_ADJ.ATTRIBUTO1,DATAS_rev.COD_DEST1,DATAS_rev.COD_DEST2
,DATAS_rev.COD_DEST3, DATAS.COD_DEST4,DATAS_rev.COD_VALUTA,DATAS_rev.COD_VALUTA_ORIGINARIA,INFO.INCOT
)
I will share the order of execution details also for normal and long run case.
Could someone please help us to overcome this issue? And also we don't know how to fix the order of the join execution. Is there any way to fix the join order execution, Please guide us.
Thanks in advance
Vinothkumar
Without a lot more detailed information, there is no way to tell exactly why your INSERT statement shows this alternating runtime behaviour.
Based on my experience, such an analysis can take quite some time and there are only few people available that are capable to perform it. If you can get someone like that to look at this, make sure to understand and learn.
What I can tell from the information shared is this
using temporary tables to structure a multi-stage data flow is the wrong thing to do on SAP HANA. Instead, use table variables in SQLScript.
if you insist on using the temporary tables, make them at least column tables; this will allow to avoid a need for some internal data materialisation.
when using joins make sure that the joined columns are of the same data type. The explain plan is full of TO_INT(), TO_DECIMAL(), and other conversion functions. Those take time, memory, and make it hard for the optimiser(s) to estimate cardinalities.
as the statement uses a lot of temporary tables, the different join orders can easily result from different volumes of data that was present when the SQL was parsed, prepared and optimised. One option to avoid this is to have HANA ignore any cached plans for the statement. The documentation has the HINTS for that.
And that is about what I can say about this with the available information.
I am dealing with a monster query ( ~800 lines ) on oracle 11, and its taking expensive resources.
The main problem here is a table mouvement with about ~18 million lines, on which I have like 30 left joins on this table.
LEFT JOIN mouvement mracct_ad1
ON mracct_ad1.code_portefeuille = t.code_portefeuille
AND mracct_ad1.statut_ligne = 'PROPRE'
AND substr(mracct_ad1.code_valeur,1,4) = 'MRAC'
AND mracct_ad1.code_transaction = t.code_transaction
LEFT JOIN mouvement mracct_zias
ON mracct_zias.code_portefeuille = t.code_portefeuille
AND mracct_zias.statut_ligne = 'PROPRE'
AND substr(mracct_zias.code_valeur,1,4) = 'PRAC'
AND mracct_zias.code_transaction = t.code_transaction
LEFT JOIN mouvement mracct_zixs
ON mracct_zias.code_portefeuille = t.code_portefeuille
AND mracct_zias.statut_ligne = 'XROPRE'
AND substr(mracct_zias.code_valeur,1,4) = 'MRAT'
AND mracct_zias.code_transaction = t.code_transaction
is there some way so I can get rid of the left joins, (union join or example) to make the query faster and consumes less? execution plan or something?
Just a note on performance. Usually you want to "rephrase" conditions like:
AND substr(mracct_ad1.code_valeur,1,4) = 'MRAC'
In simple words, expressions on the left side of the equality will prevent the best usage of indexes and may push the SQL optimizer toward a less than optimal plan. The database engine will end up doing more work than is really needed, and the query will be [much] slower. In extreme cases they can even decide to use a Full Table Scan. In this case you can rephrase it as:
AND mracct_ad1.code_valeur like 'MRAC%'
or:
AND mracct_ad1.code_valeur >= 'MRAC' AND mracct_ad1.code_valeur < 'MRAD'
I am guessing so. Your code sample doesn't make much sense, but you can probably do conditional aggregation:
left join
(select m.code_portefeuille, m.code_transaction,
max(case when m.statut_ligne = 'PROPRE' and m.code_valeur like 'MRAC%' then ? end) as ad1,
max(case when m.statut_ligne = 'PROPRE' and m.code_valeur like 'MRAC%' then ? end) as zia,
. . . -- for all the rest of the joins as well
from mouvement m
group by m.code_portefeuille, m.code_transaction
) m
on m.code_portefeuille = t.code_portefeuille and m.code_transaction = t.code_transaction
You can probably replace all 30 joins with a single join to the aggregated table.
I have this below Oracle query. It takes ages to execute.
Select Distinct Z.WH_Source,
substr(Z.L_Y_Month,0,4) || '-' || substr(Z.L_Y_Month,5) Ld_Yr_Mth,
m.model_Name, p.SR, p.PLATE_NO, pp.value, z.CNT_number, z.platform_SR_number,
z.account_name, z.owner_name, z.operator_name, z.jetcare_expiry_date, z.wave,
z.address, z.country, substr(z.CNT_status, 10) ctstatus,
ALLOEM.GET_CNT_TYRE_SR#TNS_GG(z.CNT_number, Z.WH_Source, Z.L_Y_Month,
z.platform_SR_number, '¿')
product_SR_number
From MST.ROLE p
inner join MST.model m on m.model_id = p.model_id
left join MST.ROLEproperty pp on pp.ROLE_id = p.ROLE_id
and pp.property_lookup = 'SSG-WH-ENROLL'
left join alloem.Z_SSG_HM_LOG#TNS_GG z on z.camp_ac_ROLE_id = p.ROLE_id
Where
1 = 1 or z.L_Y_Month = 1
Order By 1, 2 desc, 3,4
If i remove this line,
ALLOEM.GET_CNT_TYRE_SR#TNS_GG(z.CNT_number, Z.WH_Source, Z.L_Y_Month,
z.platform_SR_number, '¿')
it executes very fast. But, I can't remove the line. Is there any way to make this query to execute fast.?
If i remove this line,
ALLOEM.GET_CNT_TYRE_SR#TNS_GG(z.CNT_number, Z.WH_Source,
Z.L_Y_Month, z.platform_SR_number, '¿')
it executes very fast. But, I can't remove the line. Is there any way to make this query to execute fast.?
Query tuning is a complex thing. Without table structures, indexes, execution plan or statistics it is very hard to provide one universal answer.
Anyway I would try scalar subquery caching(if applicable):
ALLOEM.GET_CNT_TYRE_SR#TNS_GG(z.CNT_number, Z.WH_Source, Z.L_Y_Month,
z.platform_SR_number, '¿')
=>
(SELECT ALLOEM.GET_CNT_TYRE_SR#TNS_GG(z.CNT_number, Z.WH_Source,Z.L_Y_Month,
z.platform_SR_number, '¿') FROM dual)
Also usage of DISTINCT may indicate some problems with normalization. If possible please fix underlying problem and remove it.
Finally you should avoid using positional ORDER BY (it is commom anti-pattern).
This:
alloem.Z_SSG_HM_LOG#TNS_GG
suggests that you fetch data over a database link. It is usually slower than fetching data locally. So, if you can afford it & if your query manipulates "static" data (i.e. nothing changes in Z_SSG_HM_LOG table frequently) and - even if it does - the amount of data isn't very high, consider creating a materialized view (MV) in schema you're connected to while running that query. You can even create index(es) on a MV so ... hopefully, everything will run faster without too much effort.
This two SQL statements return equal results but first one is much slower than the second:
SELECT leading.email, kstatus.name, contacts.status
FROM clients
JOIN clients_leading ON clients.id_client = clients_leading.id_client
JOIN leading ON clients_leading.id_leading = leading.id_leading
JOIN contacts ON contacts.id_k_p = clients_leading.id_group
JOIN kstatus on contacts.status = kstatus.id_kstatus
WHERE (clients.email = 'some_email' OR clients.email1 = 'some_email')
ORDER BY contacts.date DESC;
SELECT leading.email, kstatus.name, contacts.status
FROM (
SELECT *
FROM clients
WHERE (clients.email = 'some_email' OR clients.email1 = 'some_email')
)
AS clients
JOIN clients_leading ON clients.id_client = clients_leading.id_client
JOIN leading ON clients_leading.id_leading = leading.id_leading
JOIN contacts ON contacts.id_k_p = clients_leading.id_group
JOIN kstatus on contacts.status = kstatus.id_kstatus
ORDER BY contacts.date DESC;
But I'm wondering why is it so? It looks like in the firt statement joins are done first and then WHERE clause is applied and in second is just the opposite. But will it behave the same way on all DB engines (I tested it on MySQL)?
I was expecting DB engine can optimize queries like the fors one and firs apply WHERE clause and then make joins.
There are a lot of different reasons this could be (keying etc), but you can look at the explain mysql command to see how the statements are being executed. If you can run that and if it still is a mystery post it.
You always can replace join with nested query... It's always faster but lot messy...
I have a query joining 4 tables with a lot of conditions in the WHERE clause. The query also includes ORDER BY clause on a numeric column. It takes 6 seconds to return which is too long and I need to speed it up. Surprisingly I found that if I remove the ORDER BY clause it takes 2 seconds. Why the order by makes so massive difference and how to optimize it? I am using SQL server 2005. Many thanks.
I cannot confirm that the ORDER BY makes big difference since I am clearing the execution plan cache. However can you shed light at how to speed this up a little bit? The query is as follows (for simplicity there is "SELECT *" but I am only selecting the ones I need).
SELECT *
FROM View_Product_Joined j
INNER JOIN [dbo].[OPR_PriceLookup] pl on pl.siteID = NodeSiteID and pl.skuid = j.skuid
LEFT JOIN [dbo].[OPR_InventoryRules] irp on irp.ID = pl.SkuID and irp.InventoryRulesType = 'Product'
LEFT JOIN [dbo].[OPR_InventoryRules] irs on irs.ID = pl.siteID and irs.InventoryRulesType = 'Store'
WHERE (((((SiteName = N'EcommerceSite') AND (Published = 1)) AND (DocumentCulture = N'en-GB')) AND (NodeAliasPath LIKE N'/Products/Cats/Computers/Computer-servers/%')) AND ((NodeSKUID IS NOT NULL) AND (SKUEnabled = 1) AND pl.PriceLookupID in (select TOP 1 PriceLookupID from OPR_PriceLookup pl2 where pl.skuid = pl2.skuid and (pl2.RoleID = -1 or pl2.RoleId = 13) order by pl2.RoleID desc)))
ORDER BY NodeOrder ASC
Why the order by makes so massive difference and how to optimize it?
The ORDER BY needs to sort the resultset which may take long if it's big.
To optimize it, you may need to index the tables properly.
The index access path, however, has its drawbacks so it can even take longer.
If you have something other than equijoins in your query, or the ranged predicates (like <, > or BETWEEN, or GROUP BY clause), then the index used for ORDER BY may prevent the other indexes from being used.
If you post the query, I'll probably be able to tell you how to optimize it.
Update:
Rewrite the query:
SELECT *
FROM View_Product_Joined j
LEFT JOIN
[dbo].[OPR_InventoryRules] irp
ON irp.ID = j.skuid
AND irp.InventoryRulesType = 'Product'
LEFT JOIN
[dbo].[OPR_InventoryRules] irs
ON irs.ID = j.NodeSiteID
AND irs.InventoryRulesType = 'Store'
CROSS APPLY
(
SELECT TOP 1 *
FROM OPR_PriceLookup pl
WHERE pl.siteID = j.NodeSiteID
AND pl.skuid = j.skuid
AND pl.RoleID IN (-1, 13)
ORDER BY
pl.RoleID desc
) pl
WHERE SiteName = N'EcommerceSite'
AND Published = 1
AND DocumentCulture = N'en-GB'
AND NodeAliasPath LIKE N'/Products/Cats/Computers/Computer-servers/%'
AND NodeSKUID IS NOT NULL
AND SKUEnabled = 1
ORDER BY
NodeOrder ASC
The relation View_Product_Joined, as the name suggests, is probably a view.
Could you please post its definition?
If it is indexable, you may benefit from creating an index on View_Product_Joined (SiteName, Published, DocumentCulture, SKUEnabled, NodeOrder).