druid/core
Gian Merlino 9c925b4f09
Frame format for data transfer and short-term storage. (#12745)
* Frame format for data transfer and short-term storage.

As we move towards query execution plans that involve more transfer
of data between servers, it's important to have a data format that
provides for doing this more efficiently than the options available to
us today.

This patch adds:

- Columnar frames, which support fast querying.
- Row-based frames, which support fast sorting via memory comparison
  and fast whole-row copies via memory copying.
- Frame files, a container format that can be stored on disk or
  transferred between servers.

The idea is we should use row-based frames when data is expected to
be sorted, and columnar frames when data is expected to be queried.

The code in this patch is not used in production yet. Therefore, the
patch involves minimal changes outside of the org.apache.druid.frame
package.  The main ones are adjustments to SqlBenchmark to add benchmarks
for queries on frames, and the addition of a "forEach" method to Sequence.

* Fixes based on tests, static analysis.

* Additional fixes.

* Skip DS mapping tests on JDK 14+

* Better JDK checking in tests.

* Fix imports.

* Additional comment.

* Adjustments from code review.

* Update test case.
2022-07-08 20:42:06 -07:00
..
src Frame format for data transfer and short-term storage. (#12745) 2022-07-08 20:42:06 -07:00
pom.xml Poison stupid pool (#12646) 2022-07-03 14:36:22 -07:00