1. Why Should I Care About … Partitioned Views?

2. Frederick (Rick) Lowe Data FLowe Solutions LLC
DataFLowe

3. I’m Not Here to Start the Retrolution
Partitioned tables are awesome for almost all partitioning cases
Historical takeaway from this talk – you’re not doomed if you have pre-2016 Standard Ed.
Also, there are a couple of cases where views make sense even in EE

4. First … Why Are Partitioned Tables So Exciting (review)?
Appears to be a normal table
Table is broken into multiple partitions based on the value of a single column
Migrating a partition in or out is a metadata-only operation (i.e. basically instantaneous)
Select statements can eliminate partitions

5. Working With Partitioned Tables (review)
Create a partition function and scheme
Build clustered and nonclustered indexes on the partition scheme
Views, CRUD etc reference a partitioned table pretty much like any other table
SQL Server does all the heavy lifting

6. Partitioned Table (review) Update/Insert/Select MyTable 2005? 2006?
2007?
2008?
Partition Scheme Associated With Table P0 … P1 … P2 … P3 …

7. Working With Partitioned Views
Build individual tables
Typically, create check constraints on tables
View unions together all underlying tables
*Create procedure determines which table to insert the data into
*Update/Delete also need to either determine which table to work on or operate on all
* Indicates operations can actually sometimes be done on view

8. Partitioned View Worst Case
Update
Insert
Select
UpdateMyTable
CreateMyTable
vwMyTable
2005?
2006?
2007?
2008?
Data Boundaries Coded Into View / Procs
MyTbl_05 …
MyTbl_06 …
MyTbl_07 …
MyTbl_08 …

9. Partitioned View If You’re Lucky
Update
Insert
Select
UpdateMyTable
CreateMyTable
vwMyTable
2005?
2006?
2007?
2008?
Data Boundaries Coded Into View / Procs
MyTbl_05 …
MyTbl_06 …
MyTbl_07 …
MyTbl_08 …

10. Working With Partitioned Views

11. Defining a Partitioned View
CREATE VIEW Sales.vwSalesOrderHeader AS
SELECT OrderDate, SalesOrderID, … FROM Sales.SalesOrderHeader_2005
UNION ALL
SELECT OrderDate, SalesOrderID, … FROM Sales.SalesOrderHeader_2006
SELECT OrderDate, SalesOrderID, … FROM Sales.SalesOrderHeader_2007
SELECT OrderDate, SalesOrderID, … FROM Sales.SalesOrderHeader_2008;
CREATE PROCEDURE Sales.SalesOrderHeader_Create … AS
INSERT INTO Sales.SalesOrderHeader_2008( OrderDate, SalesOrderID, ….)
VALUES( …. )

12. Adding A New Table to View
Create table with appropriate structure
Add check constraints
Import data, if appropriate
Create indexes
Add new UNION ALL to view
Update Stored Procedures

13. Removing Table From View
Update stored procedures, if necessary
Remove appropriate UNION ALL from view
Data can now be truncated / Archived / etc

14. Demo

15. “Table” Elimination
Partitioned tables only search partitions that match WHERE clause
Note: in practice, this typically isn’t a performance “game changer”
SQL Server will leverage check constraints by using startup conditions in execution plans
… so check constraints do give partitioned views similar “table elimination”

16. Use Cases For Partitioned Views

17. Limitations of Partitioned Tables
Prior to MSSQL 2016 SP1, Enterprise feature
Horizontal partitioning scheme only
Statistics tracked at table (not partition) level
Indexing defined at the table level
Partitioning can only occur on one column
Prior to MSSQL 2014, online rebuild only supported at table level

18. Vertical Partitioning
Horizontal partitioning separates groups of rows into partitions (table) or tables (view)
Vertical partitioning on the other hand separates columns from the rest of the table
Can be driven by normalization
In practice, this term is more often associated with row splitting

19. Horizontal Partition

20. Vertical Partition

21. Before Row Splitting ID_Int ID_GUID Name … Big_xml Rating 1 1a23… Anna
<doc <a name=a/>… /> 2
2ff0…
Bubba
<doc <a name=b/>… />
9001
10ab…
Goku

22. After Row Splitting ID_Int ID_GUID Name … 1 1a23… Anna 2 2ff0… Bubba
9001
10ab…
Goku
ID_Int
Big_xml
Rating 1
<… /> … 2
9001

23. Before Row Splitting ID_Int ID_GUID Name … SSN Salary 1 1a23… Anna
$150,000 2
2ff0…
Bubba
$80,000
9001
10ab…
Goku
$125,000

24. After Row Splitting ID_Int ID_GUID Name … 1 1a23… Anna 2 2ff0… Bubba
9001
10ab…
Goku
ID_Int
SSN
Salary 1
$150,000 2
$80,000 …
9001
$125,000

25. Statistics Sampling

26. Connect the Dots Simply

27. Possible Answer

28. Remember This?
2005?
2006?
2007?
2008?
Data Boundaries Coded Into View / Procs
MyTbl_05 …
MyTbl_06 …
MyTbl_07 …
MyTbl_08 …

29. Multi-Dimensional Partitioned View 2005? 2006? 2007? 2008?
Data Boundaries Coded Into View / Procs
MyTbl_05 …
MyTbl_06 …
MyTbl_07 …
Premium? no
yes
MyTbl_08 …
Fast_SSD …

30. Thank You
Rick Lowe –
DataFLowe

31. Partition Function vs Scheme
Partition Functions
Partition Scheme

32. Defining a Partitioned Table (review)
CREATE PARTITION FUNCTION MyFunction(DATE) AS RANGE RIGHT FOR VALUES (…);
CREATE PARTITON SCHEME MyPartitionScheme AS PARTITION MyFunction TO( … );
CREATE TABLE Sales.SalesOrderHeader(
OrderDate DATETIME2(3),
SalesOrderID INT IDENTITY NOT NULL, …
CONSTRAINT PK_SalesOrderHeader
PRIMARY KEY CLUSTERED(OrderDate, SalesOrderID)
ON MyPartitionScheme( OrderDate ) );

33. Moving Data Around – Partitioned Table (review)
To extract an entire partition from a table
Use ALTER TABLE SWITCH to instantly switch the partition out to a new table
Archive / delete / manipulate the new table
To add existing data to partitioned table
Get data into table with same structure/indexing
Add check constraints
Switch the new table into the partitioned table