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]    (SELECT DISTINCT   [Extent1].[ID] AS [ID]    

                        FROM  [DBA].[Person] AS [Extent1]FROM  [DBA].[Person] AS [Extent1]

                                INNER JOIN [DBA].[Sales] AS [Extent2]INNER JOIN [DBA].[Sales] AS [Extent2]

ON  EXISTSON  EXISTS (SELECT   cast(1 as bit) AS [C1] (SELECT   cast(1 as bit) AS [C1]

                                                FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]

                                                LEFT OUTER JOIN  (SELECT [Extent3].[ID] AS [ID]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)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]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)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))  )WHERE ([Extent1].[ID] = [Project1].[ID]) OR (([Extent1].[ID] IS NULL) AND ([Project2].[ID] IS NULL))  )

) AS [Distinct1]) AS [Distinct1]

  LEFT OUTER JOIN 

(SELECT [Extent5].[ID] AS [ID],  [Extent6].[SalesOrderID] AS [SalesOrderID], [Extent6].[TotalDue] AS [TotalDue],   1 AS [C1](SELECT [Extent5].[ID] AS [ID],  [Extent6].[SalesOrderID] AS [SalesOrderID], [Extent6].[TotalDue] AS [TotalDue],   1 AS [C1]

                                FROM  [DBA].[Person] AS [Extent5]FROM  [DBA].[Person] AS [Extent5]

                      INNER JOIN [DBA].[Sales] AS [Extent6] INNER JOIN [DBA].[Sales] AS [Extent6]

ON  EXISTSON  EXISTS (SELECT    cast(1 as bit) AS [C1] (SELECT    cast(1 as bit) AS [C1]

                                                FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable2]FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable2]

                                                LEFT OUTER JOIN  (SELECT [Extent9].[ID] AS [ID]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)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]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)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))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

Generated Queries: Object Relational Mapping (ORM)

WW = SELECT DISTINCT   [Extent1].[ID] AS [ID]     = SELECT DISTINCT   [Extent1].[ID] AS [ID]                            FROM  [DBA].[Person] AS [Extent1]FROM  [DBA].[Person] AS [Extent1]

                                INNER JOIN [DBA].[Sales] AS [Extent2]INNER JOIN [DBA].[Sales] AS [Extent2]ON  EXISTSON  EXISTS (SELECT   cast(1 as bit) AS [C1] (SELECT   cast(1 as bit) AS [C1]                                                FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]FROM    ( SELECT cast(1 as bit) AS X ) AS [SingleRowTable1]                                                LEFT OUTER JOIN  (SELECT [Extent3].[ID] AS [ID]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)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]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)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))  )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 ( ( WW

) AS [Distinct1]) 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

Generated Queries: ORM (cont.)

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

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

Generated Queries: HibernateQ2 = SELECT DISTINCT Device.ID,Device.NameFROM DeviceWHERE 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.%' ) ) ) )

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.%‘)

Generated Queries: Hibernate (cont.)

Q2 = SELECT DISTINCT W0.ID,W0.NameFROM Device W0WHERE ( 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.%' )

Generated Queries: Hibernate (cont.)

8

New Optimizations

Workload Platform

Comm # Stmts Unique Stmts

DB Size

Customer 1 Solaris jConnect TCP/IP

30K 15 20 MB

Customer 2 CE ESQL

ShMem

692 118 3 MB

Customer 3 Win32 ODBC

ShMem

13K 37 165 MB

New optimizations cheap queries could be 2-3 times slower

Cheap requests doesn’t mean simple queries:

{cheap, expensive} X {simple, complex}

Cardinality estimation errors

Errors in cardinality estimation for first joins:

--- 10,000,000 rows vs. 1,000 estimated rows

15min vs. 3s

SearchSpaceAnalyzer

Anisoara Nica, 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

Anisoara Nica, 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