Ali Shaik's Database Diary

  Differences between the Developer, Standard, and Enterprise Editions for SQL Server Always On Availability Groups SQL Server Always On Availability Groups is a high-availability and disaster recovery solution that is available in SQL Server Developer, Standard, and Enterprise Editions. However, the specific features and limitations of Always On Availability Groups may differ across these editions. Maximum number of replicas: Developer Edition supports up to two replicas (primary and one secondary). Standard Edition supports up to two replicas (primary and one secondary). Enterprise Edition supports up to eight replicas (one primary and seven secondary). Readable secondary replicas: Developer Edition supports readable secondary replicas for reporting or backup purposes. Standard Edition supports readable secondary replicas for reporting or backup purposes. However, it does not support read-only routing. Enterprise Edition supports both readable secondary replicas and read-only rou...

  Here are a few of the main differences: Schema: In SQL Server, you need to define a schema for your database before you can create tables and insert data. The schema defines the structure of the data and specifies the data types, constraints, and relationships between tables. In MongoDB, you do not need to define a schema before inserting data. MongoDB is a schema less database, which means it can store data in any format without pre defining a structure. Tables and Collections: In SQL Server, data is stored in tables, which are made up of rows and columns. In MongoDB, data is stored in collections, which are made up of JSON-like documents. Collections are similar to tables in that they can contain multiple documents with similar attributes, but they do not enforce a strict schema. Query Language: In SQL Server, you use the Structured Query Language (SQL) to query and manipulate data. SQL is a declarative language that uses a set of predefined commands to interact w...

Query Store  If you are working with SQL Server 2016 or higher, even Express, there is a new native tool that you should know about: Query Store. Query Store is a feature that can be enabled on any SQL Server 2016 instance or higher, even when compatibility mode is lower. In this blog post, we will explore the features of Query Store and how to configure it. Query Store Features: Query Store is a native tool that captures historical query information. Unlike previous native tools, data captured by Query Store will outlive performance changes, failovers, reboots, and even SQL upgrades because data is stored in tables inside each database. There is minimal I/O impact since the data collected is stored in memory then asynchronously persisted to disk. Query Store gathers two important parts of historical query information. First, we have plan details with stats detailing if a seek or scan was performed and the number of plans our queries have in cache. Then we have runtime stats ...