When the text and blob data type column is used in Innodb Engine. The value which are stored in that field is stored in off-page not stored in page (The default Size of Innodb page is 16kb).
My Questions are 1. What is the off-page mean? 2. How its is accessed while retrieving the value from off-page?
- What is the off-page mean
I means that it is stored in a separate area, so it doesn't bloat the main index. This way, the size of the pages can stay identical and exact (the exact storage space required for everything other types is known), and it makes accessing the data faster.
- How its is accessed while retrieving the value from off-page?
A 20-byte pointer is stored and it contains the address of the rest of the column.
PS. I think this question would be better suited for DBA