What is SQL cache dependency?
Using SQL cache dependency, you could cache your product information and create a dependency on a database table or row change. When the data changes—and only then—the cache items based on that data are invalidated and removed from the cache.
What is cache dependency?
Cache dependencies allow the application to automatically clear cached data when related objects are modified. The system uses dummy cache keys to create dependencies between cached data and other objects. Dummy keys are cache items without any data that represent objects or groups of objects.
How is cache used with SQL?
In SQL Server, the buffer cache is the memory that allows you to query frequently accessed data quickly. When data is written to or read from a SQL Server database, the buffer manager copies it into the buffer cache (aka the buffer pool).
What are dependencies in cache and types of dependencies?
Types of Cache Dependencies – Caching pages and data
- a. File based dependencies.
- b. Key-based dependencies.
- c. Time-based dependencies.
- d. All of the above.
Which of the following commands enable cache dependency?
To enable a cache dependency on a particular database, run this command: aspnet_regsql.exe -S server -U user -P password -d database -ed This creates a new table, AspNet_SqlCacheTablesForChangeNotification, in the designated database.
What method is used to add the dependency cache item?
Insert method
To set up a dependency, you create an instance of the CacheDependency class, specifying the files, keys, or directories on which the item is dependent, and then pass the dependency to the Add or Cache. Insert method.
Which method is used to add the dependent cache item?
the Insert method
Adding items to the cache using the Insert method. Adding an item to the cache and adding a dependency so that the item is removed from the cache when the dependency changes. You can set dependencies based on other cache items, on files, and on multiple objects.
How do I clear the buffer cache in SQL Server?
By cleaning the buffer pool before each test run SQL Server will have to re-read the data it needs from disk. To clean the buffer pool you execute the command: DBCC DROPCLEANBUFFERS. Next you should remove your execution plans from the procedure cache.
How does database cache work?
A database cache supplements your primary database by removing unnecessary pressure on it, typically in the form of frequently accessed read data. When the underlying data changes on the database table, the database updates its cache automatically, which is great.
Does SQL Server cache query results?
SQL Server does NOT cache results from a query. This is the important distinction. When you use application cache, you store your result-sets in Memcached RAM. Then reuse them over and over again without connecting to the database server, thus offloading workloads from your database server.
How to make a cache dependent on a SQL query?
You can use the SqlCacheDependency class to add items to your application’s Cache that are dependent on either a SQL Server database table or on an SQL query when using SQL Server 2005. You can also use this class with the directive to make an output-cached page or a user control dependent on a SQL Server database table.
How to insert SQL data into the cache?
In the code behind, to insert the data into Cache, first instantiate the SqlCacheDependency object by passing the database entry name (this name is name of the database defined in the databases element of SqlCacheDependency in the web.config file) and table name (PersonalDetail), then add it as dependency into the Cache using Cache.Insert method.
Can a cache object be inherited from SQL Server?
Establishes a relationship between an item stored in an ASP.NET application’s Cache object and either a specific SQL Server database table or the results of a SQL Server 2005 query. This class cannot be inherited. The following code example uses the SqlDataSource and GridView controls to display a database table.
When to remove a cache from a database?
Ideally, the database data would remain cached until the underlying data has been modified in the database; only then would the cache be evicted. This approach maximizes the performance benefits of caching and minimizes the duration of stale data.