The Batch operation DataBaseIndexPersist.persistIndex() is executed to perform the backup for all indices. The process for persisting each index is to:-
- Read current persisted index
- Read new or modified data from staging table data
- Generate an in-memory index with 1) + 2) above.
- Save newly generated in-memory index to the database.
- Repeat 1) to 4) for each search service.