[
https://issues.apache.org/jira/browse/PHOENIX-2417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15102141#comment-15102141
]
ASF GitHub Bot commented on PHOENIX-2417:
-----------------------------------------
Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/147#discussion_r49880903
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/schema/stats/GuidePostsInfo.java
---
@@ -53,22 +70,21 @@
* @param guidePosts
* @param rowCount
*/
- public GuidePostsInfo(long byteCount, List<byte[]> guidePosts, long
rowCount) {
- this.guidePosts = ImmutableList.copyOf(guidePosts);
- int size = 0;
- for (byte[] key : guidePosts) {
- size += key.length;
- }
- this.keyByteSize = size;
+ public GuidePostsInfo(long byteCount, ImmutableBytesWritable
guidePosts, long rowCount, int maxLength, int guidePostsCount) {
+ this.guidePosts = guidePosts;
--- End diff --
Best to make a copy of the ImmutableBytesWritable here in case the caller
uses the ptr again. Note that this doesn't copy the underlying bytes:
this.guidePosts = new ImmutableBytesWritable(guidePosts);
> Compress memory used by row key byte[] of guideposts
> ----------------------------------------------------
>
> Key: PHOENIX-2417
> URL: https://issues.apache.org/jira/browse/PHOENIX-2417
> Project: Phoenix
> Issue Type: Sub-task
> Reporter: James Taylor
> Assignee: Ankit Singhal
> Fix For: 4.7.0
>
> Attachments: PHOENIX-2417.patch, PHOENIX-2417_encoder.diff,
> PHOENIX-2417_v2_wip.patch
>
>
> We've found that smaller guideposts are better in terms of minimizing any
> increase in latency for point scans. However, this increases the amount of
> memory significantly when caching the guideposts on the client. Guidepost are
> equidistant row keys in the form of raw byte[] which are likely to have a
> large percentage of their leading bytes in common (as they're stored in
> sorted order. We should use a simple compression technique to mitigate this.
> I noticed that Apache Parquet has a run length encoding - perhaps we can use
> that.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
