| # DataMap Developer Guide |
| |
| ### Introduction |
| DataMap is a data structure that can be used to accelerate certain query of the table. Different DataMap can be implemented by developers. |
| Currently, there are two 2 types of DataMap supported: |
| 1. IndexDataMap: DataMap that leveraging index to accelerate filter query |
| 2. MVDataMap: DataMap that leveraging Materialized View to accelerate olap style query, like SPJG query (select, predicate, join, groupby) |
| |
| ### DataMap provider |
| When user issues `CREATE DATAMAP dm ON TABLE main USING 'provider'`, the corresponding DataMapProvider implementation will be created and initialized. |
| Currently, the provider string can be: |
| 1. preaggregate: one type of MVDataMap that do pre-aggregate of single table |
| 2. timeseries: one type of MVDataMap that do pre-aggregate based on time dimension of the table |
| 3. class name IndexDataMapFactory implementation: Developer can implement new type of IndexDataMap by extending IndexDataMapFactory |
| |
| When user issues `DROP DATAMAP dm ON TABLE main`, the corresponding DataMapProvider interface will be called. |
