Mysqldump generated file that is smaller size then database [closed]

Solution 1:

• The dump does not include the INDEXes other than the PRIMARY KEY.
• The dump does not include "free space" in the disk files.
• The dump is text, not binary. For example a BIGINT takes 8 bytes in the file, but if, say, the value is "1" it takes 2 bytes in the dump: "...,1,..." (the number plus one of the commas).
• On the other hand, some numbers, strings, dates, etc, will take more space in the dump.
• An empty table takes a minimum of something like 24KB on disk, but only a few hundred bytes (mostly for the CREATE TABLE) in the dump.
• The dump is a text file; look at some of it (via more or less or something like that).

So, your 3:1 shrinkage is quite feasible. And a 2:1 expansion is possible.