rash67 opened a new pull request, #12879:
URL: https://github.com/apache/druid/pull/12879
### Description
This PR should serve as a simple example of how to do entire column storage
which uses delta encoding as well as block compression (default LZ4).
Discussion:
This implementation was designed and discussed with Eric Tschetter offline.
###Details
-Add classes for writing cell values in LZ4 block compressed format.
Payloads are indexed by element number for efficient random lookup
-update SerializablePairLongStringComplexMetricSerde to use block
compression
-SerializablePairLongStringComplexMetricSerde also uses delta encoding
of the Long by doing 2-pass encoding: buffers first to find min/max
numbers and delta-encodes as integers if possible
Entry points for doing block-compressed storage of byte[] payloads
are the CellWriter and CellReader class. See
SerializablePairLongStringComplexMetricSerde for how these are used
along with how to do full column-based storage (delta encoding here)
which includes 2-pass encoding to compute a column header
<hr>
##### Key changed/added classes in this PR
* CellReader
* CellWriter
* SerializablePairLongStringComplexMetricSerde
* SerializablePairLongStringColumnSerializer
<hr>
<!-- Check the items by putting "x" in the brackets for the done things. Not
all of these items apply to every PR. Remove the items which are not done or
not relevant to the PR. None of the items from the checklist below are strictly
necessary, but it would be very helpful if you at least self-review the PR. -->
This PR has:
- [ X] been self-reviewed.
- [ X] added documentation for new or modified features or behaviors.
- [ X] added Javadocs for most classes and all non-trivial methods. Linked
related entities via Javadoc links.
- [ X] added or updated version, license, or notice information in
[licenses.yaml](https://github.com/apache/druid/blob/master/dev/license.md)
- [ X] added comments explaining the "why" and the intent of the code
wherever would not be obvious for an unfamiliar reader.
- [ X] added unit tests or modified existing tests to cover new code paths,
ensuring the threshold for [code
coverage](https://github.com/apache/druid/blob/master/dev/code-review/code-coverage.md)
is met.
- [ ] added integration tests.
- [ X] been tested in a test Druid cluster.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
