1. Why Should I Care About … Partitioned Views?

3. Frederick (Rick) Lowe
DataFLowe

4. I’m Not Here to Start the Retrolution
Partitioned tables are awesome for almost all partitioning cases
Main 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

5. 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
Enterprise edition, MSSQL 2008 and higher

6. 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

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

8. 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 ) );

9. 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 under right conditions sproc not needed

10. 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 …

11. 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 …

12. 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( …. )

13. 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

14. 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

15. Horizontal Partition

16. Vertical Partition

17. 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

18. 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

19. Statistics Sampling

20. Common Answer

21. Possible Answer

22. 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

23. Moving Data Around – Partitioned View
To separate a table from the view
Alter the view so that it no longer references table
Update stored procedures if necessary
To add existing data to partitioned view
Get data into table with same structure
Ideally, add check constraints
Update view and stored procedures to reference new table

24. Demo
Startup Conditions in
Execution Plan

25. Thank You
Rick Lowe –
DataFLowe