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https://issues.apache.org/jira/browse/PHOENIX-4278?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16360488#comment-16360488
]
ASF GitHub Bot commented on PHOENIX-4278:
-----------------------------------------
Github user ohadshacham commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/291#discussion_r167501024
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/query/ConnectionQueryServicesImpl.java
---
@@ -850,19 +849,12 @@ private void addCoprocessors(byte[] tableName,
HTableDescriptor descriptor, PTab
&& !SchemaUtil.isMetaTable(tableName)
&& !SchemaUtil.isStatsTable(tableName)) {
if (isTransactional) {
- if
(!descriptor.hasCoprocessor(PhoenixTransactionalIndexer.class.getName())) {
-
descriptor.addCoprocessor(PhoenixTransactionalIndexer.class.getName(), null,
priority, null);
- }
--- End diff --
Let's skip this for now and add a release note.
> Implement pure client side transactional index maintenance
> ----------------------------------------------------------
>
> Key: PHOENIX-4278
> URL: https://issues.apache.org/jira/browse/PHOENIX-4278
> Project: Phoenix
> Issue Type: Improvement
> Reporter: James Taylor
> Assignee: Ohad Shacham
> Priority: Major
> Attachments: PHOENIX-4278.4.x-HBase-1.3.v1.patch
>
>
> The index maintenance for transactions follows the same model as non
> transactional tables - coprocessor based on data table updates that looks up
> previous row value to perform maintenance. This is necessary for non
> transactional tables to ensure the rows are locked so that a consistent view
> may be obtained. However, for transactional tables, the time stamp oracle
> ensures uniqueness of time stamps (via transaction IDs) and the filtering
> handles a scan seeing the "true" last committed value for a row. Thus,
> there's no hard dependency to perform this on the server side.
> Moving the index maintenance to the client side would prevent any RS->RS RPC
> calls (which have proved to be troublesome for HBase). It would require
> returning more data to the client (i.e. the prior row value), but this seems
> like a reasonable tradeoff.
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