Partitioning is an optimization technique used to divide a table into certain parts based on some attributes.
This includes schema evolution, partition evolution, and table version rollback — all possible without the need for costly table rewrites or table migration.
hidden partitioning
Only data that is written to the table after evolution is partitioned with the new spec, and the metadata for this new set of data is kept separately.
Data partitioned on multiple columns creates multiple layers of folders, with each top-level folder containing one folder for each of the second-level partition values.
| 项目 | 资源 | 投入时间段 | 投入百分比(及周末加班情况) |
|---|---|---|---|
| 中银项目 | 桂权力 | 12.5 - 12.17 | 25% (12.6 周日加班半天，12.11-12.12 周末加班1天，12.15 场内出差) |