CHAPTER 7CHAPTER 7

OPTIMIZING THE SCALABILITY AND

PERFORMANCE OF AZURE TABLES

CONTENTS¢:Assigning Primary Key Values to Entities, ¢Handling Associated Entities, ¢Taking Advantage of Entity¢Group Transactions,¢ Uploading the table data, ¢ Uploading the table data, ¢Displaying the Data from Heterogeneous

Tables in Grids.

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ASSIGNING PRIMARY KEY VALUES TO ENTITIES

¢ SQL Azure Database (SADB) offers most of the relationaldatabase management features of SQL Server 2008Enterprise, but Azure Tables come to the fore whenscalability is the criterion.

¢ Azure tables’ composite primary key, which consists of concatenated Partition Key and Row Key property

¢ It provides a unique entity ID, also called an object ID, to identify and sort entities within an Azure table.

¢ Partition Key values identify table partitions for load balancing across storage nodes.

¢ Azure stores entities with the same PartitionKey value in a single location

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¢ Entities in a table having the same Partition Key value are saidto be in a locality, a locality has no partition.

¢ If a table contains multiple entities with the same PartitionKey value, unique RowKey values are required to provide aunique entity ID; otherwise, RowKey values can be emptystringsstrings

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CHOOSING PARTITION KEYS

¢ Partition Key values can be strings having a Length property value of 0KB to 32KB and cannot contain any of the following characters:

¢❑ Forward slash (/)

¢❑ Backslash (\)

¢❑ Number sign (#)¢❑ Number sign (#)

¢❑ Question mark (?)

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ADDING ROW KEYS

¢ Multiple child entities, such as OrderDetails, can occur for a single parent entity ID value (OrderID), so they require RowKey values to maintain uniqueness.

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TAKING ADVANTAGE OF ENTITY GROUP

TRANSACTIONS

¢ Early Azure Table versions provided support for ACID(atomic, consistent, isolated, and durable)

transactions for single entity types with a commonPartitionKey only.

¢ More recent table versions support Entity-GroupTransactions (EGTs).

¢ EGTs support ACID transactions for create, update, anddelete operations on batches of parent and child entities withthe same PartitionKey value 8

RULES FOR PERFORMING ENTITY GROUP

TRANSACTIONS

¢ The transaction can include at most 100 entities, and its total payload may be no more than 4 MB in size.

¢ The Table Service doesn’t support linking operations in a change set.

¢ An entity can appear only once in the transaction, and ¢ An entity can appear only once in the transaction, and only one operation may be performed against it.

¢ All entities subject to operations as part of the transaction must have the same PartitionKey value.

¢ A single batch supports multiple Insert Entity, Update Entity, Merge Entity, and Delete Entity operations, which may occur in any order

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UPLOADING TABLE DATA

¢ Azure Tables support a simplified version of the ADO.NET Data Services

¢ Supports client API for create, retrieve, update, and delete (CRUD) operations by means of the Client Services library.

¢ The create operation with the POST method returns a confirmation of the data inserted

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COMPARING PERFORMANCE OF HOMOGENEOUS

AND HETEROGENEOUS TABLE OPERATIONS

¢ The following table compares the time in seconds to upload and delete 100 OrderType entities

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DISPLAYING PARENT AND ENTITIES

¢ The Data uploads, downloading data from heterogeneoustables requires only a minor change to the LINQ to RESTquery to filter out unwanted entities

¢ The Parent can be displayed on The upper part of Data Grid¢ The Parent can be displayed on The upper part of Data GridView while child can be displayed on The lower part of DataGrid View

¢ In above table Order type is parent entity While quantities

are child entities.

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¢ The homogeneous table scan covers only 30 percent of the entities of the heterogeneous table. So they are faster than heterogeneous table

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THANK YOUTHANK YOU

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