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Generated Queries: Object Relational Mapping (ORM)

Generated Queries: Object Relational Mapping (ORM). Q1 = SELECT [Project9].[ID] AS [ID],[Project9].[C1] AS [C1],[Project9].[C2] AS [C2],[Project9].[ID1] AS [ID1],[Project9].[ SalesOrderID ] AS [ SalesOrderID ], [Project9].[ TotalDue ] AS [ TotalDue ]

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Generated Queries: Object Relational Mapping (ORM)

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  1. Generated Queries: Object Relational Mapping (ORM) Q1 = SELECT [Project9].[ID] AS [ID],[Project9].[C1] AS [C1],[Project9].[C2] AS [C2],[Project9].[ID1] AS [ID1],[Project9].[SalesOrderID] AS [SalesOrderID], [Project9].[TotalDue] AS [TotalDue] FROM ( SELECT         [Distinct1].[ID] AS [ID],        1 AS [C1],        [Project8].[ID] AS [ID1],        [Project8].[SalesOrderID] AS [SalesOrderID],         [Project8].[TotalDue] AS [TotalDue],        [Project8].[C1] AS [C2]         FROM  (SELECT DISTINCT   [Extent1].[ID] AS [ID]                 FROM  [DBA].[Person] AS [Extent1]                 INNER JOIN [DBA].[Sales] AS [Extent2] ON  EXISTS (SELECT   cast(1 as bit) AS [C1]                         FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]                         LEFT OUTER JOIN  (SELECT [Extent3].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent3]  WHERE [Extent2].[ID] = [Extent3].[ID] )AS [Project1] ON cast(1 as bit) = cast(1 as bit)                         LEFT OUTER JOIN  (SELECT  [Extent4].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent4]  WHERE [Extent2].[ID] = [Extent4].[ID] ) AS [Project2] ON cast(1 as bit) = cast(1 as bit) WHERE ([Extent1].[ID] = [Project1].[ID]) OR (([Extent1].[ID] IS NULL) AND ([Project2].[ID] IS NULL))  ) ) AS [Distinct1] LEFT OUTER JOIN  (SELECT [Extent5].[ID] AS [ID],  [Extent6].[SalesOrderID] AS [SalesOrderID], [Extent6].[TotalDue] AS [TotalDue],   1 AS [C1]                 FROM  [DBA].[Person] AS [Extent5]            INNER JOIN [DBA].[Sales] AS [Extent6] ON  EXISTS (SELECT    cast(1 as bit) AS [C1]                         FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable2]                         LEFT OUTER JOIN  (SELECT [Extent9].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent9]  WHERE [Extent6].[ID] = [Extent9].[ID] )AS [Project5] ON cast(1 as bit) = cast(1 as bit)                         LEFT OUTER JOIN  (SELECT  [Extent8].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent8]  WHERE [Extent6].[ID] = [Extent8].[ID] )AS [Project6] ON cast(1 as bit) = cast(1 as bit) WHERE ([Extent5].[ID] = [Project5].[ID]) OR (([Extent5].[ID] IS NULL) AND ([Project6].[ID] IS NULL))                 ) ) AS [Project8] ON ([Project8].[ID] = [Distinct1].[ID]) OR (([Project8].[ID] IS NULL) AND ([Distinct1].[ID] IS NULL)) )  AS [Project9] ORDER BY [Project9].[ID] ASC, [Project9].[C2] ASC

  2. Generated Queries: ORM (cont.) W = SELECT DISTINCT   [Extent1].[ID] AS [ID]                 FROM  [DBA].[Person] AS [Extent1]                 INNER JOIN [DBA].[Sales] AS [Extent2] ON  EXISTS (SELECT   cast(1 as bit) AS [C1]                         FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]                         LEFT OUTER JOIN  (SELECT [Extent3].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent3]  WHERE [Extent2].[ID] = [Extent3].[ID] )AS [Project1] ON cast(1 as bit) = cast(1 as bit)                         LEFT OUTER JOIN  (SELECT  [Extent4].[ID] AS [ID]                                 FROM [DBA].[Person] AS [Extent4]  WHERE [Extent2].[ID] = [Extent4].[ID] ) AS [Project2] ON cast(1 as bit) = cast(1 as bit) WHERE ([Extent1].[ID] = [Project1].[ID]) OR (([Extent1].[ID] IS NULL) AND ([Project2].[ID] IS NULL))  ) Q1 = SELECT [Project9].[ID] AS [ID],[Project9].[C1] AS [C1],[Project9].[C2] AS [C2],[Project9].[ID1] AS [ID1],[Project9].[SalesOrderID] AS [SalesOrderID],[Project9].[TotalDue] AS [TotalDue] FROM ( SELECT         [Distinct1].[ID] AS [ID],        1 AS [C1],        [Project8].[ID] AS [ID1],        [Project8].[SalesOrderID] AS [SalesOrderID],         [Project8].[TotalDue] AS [TotalDue],        [Project8].[C1] AS [C2]         FROM   ( W ) AS [Distinct1]   LEFT OUTER JOIN  ( W ) AS [Project8] ON ([Project8].[ID] = [Distinct1].[ID]) OR (([Project8].[ID] IS NULL) AND ([Distinct1].[ID] IS NULL)) )  AS [Project9] ORDER BY [Project9].[ID] ASC, [Project9].[C2] ASC

  3. Generated Queries: ORM (cont.) Q1 = select  Extent6.ID as,  1 as C1,  1 as C2, Extent6.ID as ID1,   Extent6.SalesOrderID as SalesOrderID, Extent6.TotalDue as TotalDue from DBA.Sales as Extent6 order by Extent6.ID as ID asc

  4. ORM • Very unique features different than human-written SQL queries: • EXISTS(subquery) predicates in the ON clause • Similar query blocks used in many FROM clauses • Cannot change the ‘application’ to simplify or generate better queries • LOJ with exactly 1 row in the preserved side • The join condition is inside the correlated derived table • ON conditions of the form “1=1” • Semantic transformations: • 7 new semantic transformations implemented • 1 patent select  Distinct1.ID as ID as ID,  1 as C1 as C1,  1 as C1 as C2 as C2, Extent6.ID as ID as ID1 as ID1,   Extent6.SalesOrderID as SalesOrderID as SalesOrderID as SalesOrderID, Extent6.TotalDue as TotalDue as TotalDue as TotalDue from(select distinct  Extent2.ID as ID      from DBA.Sales as Extent2) as Distinct1(ID)        left outer join DBA.Sales as Extent6,     on Extent6.ID as ID = Distinct1.ID order by Distinct1.ID as ID asc

  5. Generated Queries: Hibernate Q2 = SELECT DISTINCT Device.ID,Device.Name FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT DISTINCT Device.ID FROM Device WHERE Device.ID IN (SELECT Device.ID FROM Device,Entry WHERE Device.dbId = Entry.dd AND UPPER(Entry.ss) LIKE '%192.16.%') OR Device.ID IN ( ( SELECT ID FROM Device WHERE ( UPPER(Device.sName) LIKE '%SSMC%' ) ) ) ) OR Device.ID IN ( ( SELECT ID FROM Device WHERE ( UPPER(Device.sName) LIKE '%SSTB%' ) ) ) ) OR Device.ID IN ( ( SELECT dcrDeviceId FROM Device WHERE ( UPPER(Device.sName) LIKE '%XHFH%' ) ) ) ) OR Device.ID IN ( ( SELECT ID FROM Device WHERE ( UPPER(Device.Name) LIKE '%SSTB%' ) ) ) ) OR Device.ID IN ( ( SELECT ID FROM Device WHERE ( UPPER(Device.Name) LIKE '%XHFH%' ) ) ) ) OR Device.ID IN ( ( SELECT Device.ID FROM Device,Entry WHERE ( ( Device.dbId = Entry.dd ) ) AND ( UPPER(Entry.ss) LIKE '%129.196.9.%' ) ) ) )

  6. Generated Queries: Hibernate (cont.) sq(c0,c1): select DISTINCT T.X from T where T.X IN (select T.X from T JOIN R where R.Y like c0) or T.X IN (select T.X from T where T.Y like c1) sq(co,c1,…,cn): select DISTINCT T.X from T where T.X IN ( sub(c0,c1,..,c(n-1)) ) or T.X IN (select T.X from T where T.Y like cn) sq('%192.16.%‘, '%SSMC%, '%SSTB%‘, '%XHFH%, '%SSTB%‘, '%XHFH%‘, '%129.196.9.%‘)

  7. Generated Queries: Hibernate (cont.) Q2 = SELECT DISTINCT W0.ID,W0.Name FROM Device W0 WHERE ( W0.ID IS NOT NULL and ( W0.ID IN (SELECT W9.ID FROM Device W9,Entry WHERE W9.dbId = Entry.dd AND UPPER(Entry.ss) LIKE '%192.16.%') ) OR ( UPPER(W0.sName) LIKE '%SSMC%' ) OR ( UPPER(W0.sName) LIKE '%SSTB%' ) OR ( UPPER(W0.sName) LIKE '%XHFH%' ) OR (UPPER(W0.Name) LIKE '%SSTB%' ) OR (UPPER(W0.Name) LIKE '%XHFH%' ) OR W0.ID IN ( ( SELECT W12.ID FROM Device W12,Entry WHERE W12.dbId = Entry.dd AND UPPER(Entry.ss) LIKE '%129.196.9.%' )

  8. New Optimizations New optimizations  cheap queries could be 2-3 times slower Cheap requests doesn’t mean simple queries: {cheap, expensive} X {simple, complex}

  9. Cardinality estimation errors Errors in cardinality estimation for first joins: --- 10,000,000 rows vs. 1,000 estimated rows  15min vs. 3s

  10. SearchSpaceAnalyzer AnisoaraNica, Daniel S. Brotherston, David W. Hillis “Extreme Visualization of Query Optimizer Search Spaces”, ACM SIGMOD International Conference on Management of Data, SIGMOD 2009, 1067-1070

  11. AnisoaraNica, Daniel S. Brotherston, David W. Hillis “Extreme Visualization of Query Optimizer Search Spaces”, ACM SIGMOD International Conference on Management of Data, SIGMOD 2009, 1067-1070

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