Am very new to azure federation.In my project there is an existing SQL azure database and now we want to use azure federation for scaling that database.
How can I achieve this on my existing table myCustomer. Am planning to federate the table based on customer_Id. any relevant tutorial available?.From where should i begin.
By Federation do I have to change my existing queries used in the project.?
Thanks.
A rough summary of the changes you need to make to federate your database are:
Decide on an id you will federate on (e.g. user id)
For each table you wish to federate alter your table schema so the federation key is part of the primary key, and annotate the table so it knows which column is the federation key.
For each query that is run against a federated table you need ensure that the connection used is redirected towards the correct federation.
This last step is currently done by adding the USE FEDERATION statement to your queries. It can be a little tricky to implement if you are using Entity Framework or Linq. Something else to be cautious of in this area is making sure the USE FEDERATION statement is re-run if your transient error handling kicks in.
The links Alexander posted are all good to read.
Did you read the article by George Huey in MSDN Magazine?
It covers transition from an existing SQL or Azure SQL DB to a DB with federations in the section called "Migrating Database Schema from SQL Server or SQL Azure to SQL Azure Federation".
Right after that I would recommend to read the tutorial on data querying (part1, part2).
You will have to change your queries if they want to access the data from federations. Basically, every federation is an independent SQL database and you have first to establish connection to correct federation before querying for data.
There are also some peculiarities how to use federations with Entity Framework, partially due to additional overhead for connection to federation instance, and partially because federations do not provide support for MARS operations (article).
Related
I am planning to make a software (ASP.NET 4.6.1 MVC with Entity Framework), which does a lot of reading from DB. Therefor I have one database, which contains all global information, projects etc. and now I am thinking to either bring all the content into the same DB but in different tables or to create a DB for each bigger group.
Now as there is a lot of reading going on, is it bad practise to have the connection information in the main db and then to connect to a different DB? Otherwise I would have the project information in the primary database and the content in a different table on the same DB.
Are there any notable delays to connect to a different DB to retrive the information?
If it's all your data, for your application, it should all go in the same database. Definitely use different tables. You should read up on entity design and normalization... and if you really need to do that, you may already be in over your head.
I am new to Oracle database and I wanted to create a database in Oracle. I followed this link to create a database:
http://www.fehily.com/books/createdb/createdb_oracle_11g_2.html
In Microsoft SQL Server, when we create a database, we use the create database command and the database creation is instantaneous [within fraction of seconds], but the Database Tool as described in link above took couple of minutes to create the database. Is database creation in Oracle this much slower?
Searching more about it, I have a feeling that this database created using above tool in Oracle is not equivalent to the database we create in SQL Server. Rather, the schema/user in oracle is appearing to be equivalent to database in SQL Server. Is it true?
So, If I want multiple databases in Oracle, do I create a single database and then multiple schemas inside that single database? And then are those multiple Schemas are my databases?
I am very much confused about all this. Can someone please refer me to a nice article/book that explains these things in oracle in detail?
For most purposes, yes you would indeed map a SQL server database to an Oracle schema (=user).
The term "database" in Oracle does not mean the same as in SQL Server. An Oracle "database" (from a technical point of view) is more like a SQL Server instance/installation, rather than a "database" in SQL Server.
SQL Server has two levels of namespace: database and schema. Whereas Oracle only has a single level of namespaces: a schema (which has a 1:1 relation to a user)
SQL Server and Oracle both support Schema.
A Schema is like a new database but it is not a new database
Maybe you are confused, Mysql doesn't support schemas but SQL server offers full support for it.
In mysql your database is a schema, to only difference is that it doesn't support multi schemas
For the part of creating multi databases or a single database if multiple schemas it all depend in your specific situation, you should test thinks like performance and how much money you want to spend, a multi database approach can be very expensive unlike a multi Schema approach
I want to create a new project on contract management system. In this I have to manage multiple organizations and want to create new instance in sql server dynamically for each organization in a saas environment. How is this posiible? I am using asp.net for development. Any help would be appreciated.
A true SaaS application has a single application and database. It has the ability to have multiple tenants use the application. All data in the database needs to know what tenant it belongs too.
For instance if you have a booking system: Your customers sign up to use the software and become a row in the customer table with an ID. When a booking is made it has a customerID column as a foreign key to the customer table. Then all reports, booking views etc are done for that tenant using their customer id. You as a service provider can then run reports on all customers/tenants for your own purposes. Multiple tenants can use the system and all their data be in the same set of tables. This then means when you need to cluster replicate backup etc it is a single db, and a single migration for schema updates.
See these wiki's on multitenancy and SaaS
This of course requires your DB schema (and your app) to support this - if you are unable to change the schema then there are a number of options to up a new DB based upon the technology you are using. If you are using code first EF, then there will be db creation and migration scripts you can use. Otherwise it may justhave to be a sql script you have to generate and then maintain and run this each time a new customer is required. Personally i would rather have a single DB with an appropriate schema.
I'm currently developing an app where the users are first asked to create an account trough a website (ASP.NET) to use the app. For a special reason I need to automatically generate a database for each customer creating an account, on the hosted SQL Server. The databases for all the customers are the same.
I was thinking about doing like that: as I have the script for creating the database, I was thinking to insert it in stored procedure or a trigger that will be launched as soon as the user has fully created his account.
I don't really see other solutions, maybe somebody could give me some guidelines? Thanks in advance.
I think such a design has been shown to not scale. I'd recommend redesigning the schema to allow multiple customers in a single database.
Amazon does not such thing. Neither should you.
I agree duffymo on you would have scalability issues.
However there are situations where in you might prefer separate database as your multi-tenant data approach.
In my last project I had to adopt separate DB approach as business wanted complete isolation for each customer. It was a school administrative system and number of customer was not expected to grow in more than three digits in 5-10 years time.
So the solution I designed was, I used Entity Framework code first approach. Every school will have a unique school identifier which will be used to name the database uniquely for each school. The connection string was generated at runtime obviously. A connection factory was used to create the appropriate DataContext based on passed school identifier. The database is created on first usage if not exist. At the same time SQL script was executed to create db users during db creation if not exist.
If this approach sounds appealing I can share code snippet if that helps.
Am very new to azure federation.In my project there is an SQL azure database and now we want to use azure federation for scaling that database.
Is it possible to Federate the existing table ?.
How can I achieve this on my existing table casedetails. Am planning to federate the table based on customer_Id.From where should i begin.
in my scenario casedetails table against customerid which is the FK from Customer table.
Will it affect the queries used in the existing web application to fetch and insert values to the database ?.
How can i migrate data into the federated databse.. I am also facing a problem from identity not supported in federation. few of my tables contains identity specification and lots of data. Please reply if u have any insight relating to the problem.
Thanks in advance.