Thursday, October 8, 2015

SQL - Data Pages

There are two types of sql pages -
User Data Pages - Stores data inserted by user in pages
System Configuration Pages - IAM Page, Index Page etc

Index Allocation Map (IAM) Page - Store information about actual data pages, Page_type =10
Data Page - Stores Actual data. Page_Type =1
Page id 697 is IAM page that contains information of data pages like page id 696, 698..

Sql stores data in one page if data exceeded it start to write data in next new page and so on.

One page size total 8 KB = 8192 Bytes

--------------------
Section-1
Page Header 92 Bytes
--------------------
Section-2
Actuall Data Uses remaining Bytes out of 8192
--------------------
Section-3
Offset Table 2Bytes per record (stored in section 2)
--------------------

No comments:

Post a Comment

CI/CD - Safe DB Changes/Migrations

Safe DB Migrations means updating your database schema without breaking the running application and without downtime . In real systems (A...