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Home -> Community -> Mailing Lists -> Oracle-L -> data migration
Hi,
We are planning to do two-phase data migration - split by data. In first phase, about 10% of the data will be moved as is - without changing the primary keys (generated from sequences). Once we start using the database with phase 1 data, sequences will generate new primary keys and add to this data - which could be same as primary key for the remaining data, which is not yet migrated. In phase 2, to avoid unique constraint problems, we'll add 1,000,000 to primary keys before we migrate remaining data. This will lead to imbalance of primary keys. After complete migration, we'll have about 10% of the keys with low values and remaining with very high values. What is the impact of this huge gap in primary keys? How will be the performance affected? Is there a way in which we can avoid this huge gap in primary keys (We do not have an option of going for single migration. Business needs force us to test the application with partial data. ) One option I thought of is to use high value keys in first migration itself - but when sequences reach these high values, we'll have same problems of unique constraint being violated.
Thanks.
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