SQL-Server Column Attributes
Lesson 1
Column Attributes for Table
Before you learn how to create, modify, and delete tables in a database, it is important to understand the attributes that are available for columns in SQL Server tables. This is primarily because you will use these attributes when you create or modify tables or design your data model. As discussed later in this module, a table is made up of one or more columns.
These columns, also known as fields, define how the data is stored in a table.
Each one of the columns is made up of attributes and these attributes are discussed throughout this module.
Operational analytics: Columnstore on in-memory tables
No explicit delta rowgroup
Rows (tail) not in columnstore stay in in-memory OLTP table No columnstore index overhead when operating on tail
Background task migrates rows from tail to columnstore in chunks of 1 million rows not changed in last 1 hour.
- Deleted Rows Table (DRT) – Tracks deleted rows
- Columnstore data fully resident in memory Persisted together with operational data
- No application changes required
Learning Objectives
After completing this module, you will be able to:- Identify the correct datatypes to use for your columns
- Specify length, precision, and scale for your columns
- State when to allow null values
- Specify default values for your columns
- Use identity and ROWGUIDCOL flags
- Create and use your own datatypes