SQL Server 2014 for Developers (Cristian Lefter)

Premium community conference on Microsoft technologies itcampro@ itcamp14#

SQL Server 2014 for Developers

Cristian Lefter, SQL Server MVP http://about.me/CristianLefter


Huge thanks to our sponsors & partners!


WHAT’S NEW IN DATABASE ENGINE

SQL Server 2014


• Code name Hekaton• Memory-optimized Tables• Natively compiled stored procedures• It’s all about optimism versus pessimism• 100x times faster – how?• It’s a project started in Microsoft Research • Hekaton Team: Cristian Diaconu• It also applies to Table-Valued Parameters and

Table Variables

CREATE TYPE [Sales].[SalesOrderDetailType_inmem] AS TABLE(

[OrderQty] [smallint] NOT NULL,

[ProductID] [int] NOT NULL,

[SpecialOfferID] [int] NOT NULL,

[LocalID] [int] NOT NULL,

INDEX [IX_ProductID] HASH ([ProductID]) WITH ( BUCKET_COUNT = 8),

INDEX [IX_SpecialOfferID] NONCLUSTERED

)

WITH ( MEMORY_OPTIMIZED = ON )

In-memory OLTP


• Not for everyone • Optimistic Multi-version Concurrency Control • Best scenario: highly concurrent workloads using small transactions

In-memory OLTP (cont.)


In-memory OLTP (cont.)

Workload Pattern Implementation Scenario Benefits

High data insertion rate from multiple concurrent connections.

Primarily append-only store.Unable to keep up with the insert workload.

Eliminate contention.Reduce logging.

Read performance and scale with periodic batch inserts and updates.

High performance read operations, especially when each server request has multiple read operations to perform. Unable to meet scale-up requirements.

Eliminate contention when new data arrives.Lower latency data retrieval.Minimize code execution time.

Intensive business logic processing in the database server.

Insert, update, and delete workload.Intensive computation inside stored procedures. Read and write contention.

Eliminate contention.Minimize code execution time for reduced latency and improved throughput.

Low latency. Require low latency business transactions which typical database solutions cannot achieve.

Eliminate contention.Minimize code execution time.Low latency code execution.Efficient data retrieval.

Session state management.

Frequent insert, update and point lookups.High scale load from numerous stateless web servers.

Eliminate contention. Efficient data retrieval. Optional IO reduction or removal, when using non-durable tables


• Buffer Pool Extension to SSD (Solid State Disks)• Only “clean” pages are stored to the Buffer Pool

Extension• Increased random I/O throughput• Reduced I/O latency• Increased transaction throughput• Improved read performance with a larger hybrid buffer

pool• A caching architecture that can take advantage of

present and future low-cost memory drives• Supported in Standard and Enterprise editions• Best scenario: databases larger than available memory

Buffer Pool Extension


• SELECT … INTO can operate in parallel

• Database compatibility level at least 110.

• Main benefit – performance

SELECT … INTO can run in parallel


• Customize the wait priority of an online operation using the WAIT_AT_LOW_PRIORITY option

Syntax:<low_priority_lock_wait>::= {

WAIT_AT_LOW_PRIORITY ( MAX_DURATION = <time> [ MINUTES ] ,

ABORT_AFTER_WAIT = { NONE | SELF | BLOCKERS } ) }

Example:ALTER INDEX ALL ON Production.Product REBUILD WITH

(

FILLFACTOR = 80,

SORT_IN_TEMPDB = ON,

STATISTICS_NORECOMPUTE = ON,

ONLINE = ON ( WAIT_AT_LOW_PRIORITY ( MAX_DURATION = 4 MINUTES, ABORT_AFTER_WAIT = BLOCKERS ) ),

DATA_COMPRESSION = ROW

);

Managing the lock priority of online operations


• The cardinality estimator is re-designed in SQL Server 2014

• Improve query plans (improved query performance)

Example:

SELECT P.EnglishProductName, F.OrderDate

FROM [dbo].[FactInternetSales_V2] F

JOIN [dbo].[DimProduct] P

ON F.ProductKey = P.ProductKey

(1268358 row(s) affected)

New Design for Cardinality Estimation

SQL Server 2014 SQL Server 2012


• The individual partitions of partitioned tables can now be rebuilt online.• Can be used with Managed Lock Priority feature.• Increases database availability.Partial Syntax:

ALTER INDEX { index_name | ALL } ON <object> {

REBUILD

[ PARTITION = ALL ]

[ WITH ( <rebuild_index_option> [ ,...n ] ) ]

| [ PARTITION = partition_number

[ WITH ( <single_partition_rebuild_index_option> ) [ ,...n ] ] ... } [ ; ]

<single_partition_rebuild_index_option> ::=

{

SORT_IN_TEMPDB = { ON | OFF } | MAXDOP = max_degree_of_parallelism

| DATA_COMPRESSION = { NONE | ROW | PAGE | COLUMNSTORE | COLUMNSTORE_ARCHIVE} }

| ONLINE = { ON [ ( <low_priority_lock_wait> ) ] | OFF }

}

Partition Switching and Indexing


• Specifying the encryption algorithm and the encryptor (a Certificate or Asymmetric Key)

• All storage destinations: on-premises and Window Azure storage are supported.

• Encryption Algorithm supported: AES 128, AES 192, AES 256, and Triple DES

• Encryptor: A certificate or asymmetric Key

• For restore, the certificate or the asymmetric key used to encrypt the backup file, must be available on the instance that you are restoring to.

Backup Encryption


• Reduce latency using delayed durable transactions

• Delayed durable transaction means that the control is return to the client before the transaction log record is written to disk

• Can be controlled at:– The database level

– The COMMIT level

– The ATOMIC block level

Syntax:

-- at the database level

ALTER DATABASE dbname

SET DELAYED_DURABILITY = DISABLED | ALLOWED | FORCED;

-- at the COMMIT level

COMMIT TRANSACTION WITH (DELAYED_DURABILITY = ON);

-- at the ATOMIC block level

BEGIN ATOMIC WITH (DELAYED_DURABILITY = ON, ...)

Delayed Durability


• Column-based data storage.

• Optimized for bulk loads and read-only queries.

• Up to 10x query performance and up to 7x data compression.

• SQL Server 2012:

– nonclustered columnstore indexes

– batch mode processing

– nonclustered columnstore indexes result in a read-only table

• SQL Server 2014

– updatable clustered columnstore indexes

– archival data compression

Updateable Clustered Columnstore Indexes

• In SQL Server, a clustered columnstore index:– Available in Enterprise, Developer, and Evaluation editions

– Is the primary storage method for the entire table.

– Has no key columns. All columns are included columns.

– Is the only index on the table. It cannot be combined with any other indexes.

– Rebuilding the columnstore index requires an exclusive lock on the table or partition

• Best scenario: application requiring large scans and aggregations


• Statistics can be created at partition level.

• New partition won’t require statistics update for the entire table!

• INCREMENTAL option

• Not supported for:– Statistics created with indexes that are not partition-aligned with the base table.

– Statistics created on AlwaysOn readable secondary databases.

– Statistics created on read-only databases.

– Statistics created on filtered indexes.

– Statistics created on views.

– Statistics created on internal tables.

– Statistics created with spatial indexes or XML indexes.

Example:

UPDATE STATISTICS MyTable(MyStatistics)

WITH RESAMPLE ON PARTITIONS(3, 4);

Incremental Statistics


• Physical IO Control using MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings for a resource pool.

• The MAX_OUTSTANDING_IO_PER_VOLUMEoption sets the maximum queued I/O operations per disk volume.

Resource Governor enhancements for physical IO control


Enhanced Security


• Allows monitoring queries in real time.

• SET STATISTICS PROFILE ON or SET STATISTICS XML ON are necessary to serialize the requests of sys.dm_exec_query_profiles and return the final results

The sys.dm_exec_query_profiles DMV


Partial Syntax:

--Disk-Based CREATE TABLE Syntax

CREATE TABLE [ database_name . [ schema_name ] . | schema_name . ]

table_name [ AS FileTable ]

( { <column_definition> | <computed_column_definition>

| <column_set_definition> | [ <table_constraint> ]

| [ <table_index> ] [ ,...n ] } )... [ ; ]

< table_index > ::=

INDEX index_name [ CLUSTERED | NONCLUSTERED ] (column [ ASC | DESC ]

[ ,... n ] )

[ WITH ( <index_option> [ ,... n ] ) ]

[ ON { partition_scheme_name (column_name ) | filegroup_name

| default }]

Example:

CREATE TABLE dbo.MyTable

(

i INT, INDEX idx_MyTable_i NONCLUSTERED(i DESC)

);

Inline specification of CLUSTERED and NONCLUSTERED


DEMO

SQL Server 2014 - What’s New in Database engine


Q & A

Date post:	13-May-2015
Category:	Technology
Upload:	itcamp
View:	166 times
Download:	6 times

SQL Server 2014 for Developers (Cristian Lefter)

Technology