Please see below for general DB migration testing process.
1. DB tables definition verification:
a. Verify the table definition is same as with the Oracle. This will includes number of columns, column data types and primary keys.
2. Data comparison:
a. Compare data with existing Oracle either row level or table level.
b. Make sure to verify special characters are storing properly in MySQL.
c. Do all the functional tests here if the tables are connected with applications.
3. Sequences and Unique keys:
a. Verify unique key constraints are not storing duplicates.
b. Verify sequences are generating properly (DBAs maintain different sequences for different tables based DB architecture)
a. Verify the replication is happening properly (one way or two way…..based on the replication type)
5. Procedure testing:
a. Execute the procedures in packages with all the valid and invalid IN values and verify the OUT parameters data.
b. Repeat the above step by comparing with Oracle (if the same procedure is there in Oracle)
c. Repeat the above steps and verify the appropriate tables data is getting stored properly.
d. Verify NULL values as IN in both the DBs procedures and see the output should be same.
e. Verify all the error messages are coming properly or not with valid error text.
f. Verify timestamp and date formats.
g. Verify unique keys and sequences.
h. Verify whether procedure is going to infinite loop and getting hang in any case.
6. Performance testing:
a. Will be taken care by DBAs.