[
https://issues.apache.org/jira/browse/PHOENIX-3744?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16023277#comment-16023277
]
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_r118314328
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/mapreduce/util/PhoenixConfigurationUtil.java
---
@@ -192,6 +196,18 @@ public static void setOutputTableName(final
Configuration configuration, final S
public static void setUpsertColumnNames(final Configuration
configuration,final String[] columns) {
setValues(configuration, columns, MAPREDUCE_UPSERT_COLUMN_COUNT,
MAPREDUCE_UPSERT_COLUMN_VALUE_PREFIX);
}
+
+ public static void setSnapshotNameKey(final Configuration
configuration, final String snapshotName) {
+ Preconditions.checkNotNull(configuration);
+ Preconditions.checkNotNull(snapshotName);
+ configuration.set(SNAPSHOT_NAME_KEY, snapshotName);
--- End diff --
The idea of having the snapshot name in the configuration is not going to
translate well when we want to expose snapshot reads for queries in general as
the configuration is a global object.
> 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)
