adding a configuration type (masking.yml) that doesn't change data cardinality

[kibitan]

background

when we want to use anonymized data for performance tuning purpose, we don't want to change data cardinality in records, otherwise, it is not showing the correct sql execution plan.

grammar

pass with digit

users:
  email:  anonymized+%{hash,4}@example.com

expected result

before

expected result

MySQL [mydb]> SELECT id, email FROM users ORDER BY id;
+----+----------------------------+
| id | email                      |
+----+----------------------------+
|  1 | [email protected]            |
|  2 | [email protected]          |
|  3 | [email protected]            |
+----+----------------------------+

MySQL [mydb]> SELECT id, email FROM users ORDER BY id;
+----+----------------------------+
| id | email                      |
+----+----------------------------+
|  1 | [email protected] | <- same data outputs same data
|  2 | [email protected] |
|  3 | [email protected] | <- same data outputs same data
+----+----------------------------+

Tech tips

• it can be a performance regression

[kibitan]

this is same with #71