[
https://issues.apache.org/jira/browse/PHOENIX-3744?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16023258#comment-16023258
]
ASF GitHub Bot commented on PHOENIX-3744:
-----------------------------------------
Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/239#discussion_r118311801
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/mapreduce/util/PhoenixMapReduceUtil.java
---
@@ -63,6 +67,66 @@ public static void setInput(final Job job, final Class<?
extends DBWritable> inp
PhoenixConfigurationUtil.setSchemaType(configuration,
SchemaType.QUERY);
}
+ /**
+ *
+ * @param job
+ * @param inputClass DBWritable class
+ * @param snapshotName The name of a snapshot (of a table) to read from
+ * @param tableName Input table name
+ * @param restoreDir a temporary dir to copy the snapshot files into
+ * @param conditions Condition clause to be added to the WHERE clause.
Can be <tt>null</tt> if there are no conditions.
+ * @param fieldNames fields being projected for the SELECT query.
+ */
+ public static void setInput(final Job job, final Class<? extends
DBWritable> inputClass, final String snapshotName, String tableName,
--- End diff --
Why wouldn't we want to take the snapshot here instead of passing in the
snapshot name?
> Support snapshot scanners for MR-based queries
> ----------------------------------------------
>
> Key: PHOENIX-3744
> URL: https://issues.apache.org/jira/browse/PHOENIX-3744
> Project: Phoenix
> Issue Type: Bug
> Reporter: James Taylor
> Assignee: Akshita Malhotra
> Attachments: PHOENIX-3744.patch
>
>
> HBase support scanning over snapshots, with a SnapshotScanner that accesses
> the region directly in HDFS. We should make sure that Phoenix can support
> that.
> Not sure how we'd want to decide when to run a query over a snapshot. Some
> ideas:
> - if there's an SCN set (i.e. the query is running at a point in time in the
> past)
> - if the memstore is empty
> - if the query is being run at a timestamp earlier than any memstore data
> - as a config option on the table
> - as a query hint
> - based on some kind of optimizer rule (i.e. based on estimated # of bytes
> that will be scanned)
> Phoenix typically runs a query at the timestamp at which it was compiled. Any
> data committed after this time should not be seen while a query is running.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
