Reputation: 1505
I have dumped a database using phpmyadmin and had 390MB and then imported it using command line into new database, then it showed the size 360.
Why this imported database is smaller? Thanks.
Upvotes: 2
Views: 451
Reputation: 39950
When you delete data from a database, the records usually aren't actually deleted from the database files, just marked as deleted – the space can be reused for new records later. When you export a database, these deleted records naturally aren't exported, or recreated when you import the database.
This reuse saves a little time when records are added, because you don't always have to make the file larger. And it saves a lot of time when deleting records – deleting something from the middle of a file involves shifting all the data that comes after it.
Upvotes: 2