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https://issues.apache.org/jira/browse/PHOENIX-538?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14512267#comment-14512267
]
ASF GitHub Bot commented on PHOENIX-538:
----------------------------------------
Github user samarthjain commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/77#discussion_r29098096
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/coprocessor/MetaDataEndpointImpl.java
---
@@ -700,6 +1007,29 @@ private PTable loadTable(RegionCoprocessorEnvironment
env, byte[] key,
return null;
}
+ private PFunction loadFunction(RegionCoprocessorEnvironment env,
byte[] key,
+ ImmutableBytesPtr cacheKey, long clientTimeStamp, long
asOfTimeStamp)
+ throws IOException, SQLException {
+ HRegion region = env.getRegion();
+ Cache<ImmutableBytesPtr,PMetaDataEntity> metaDataCache =
GlobalCache.getInstance(this.env).getMetaDataCache();
+ PFunction function =
(PFunction)metaDataCache.getIfPresent(cacheKey);
+ // We always cache the latest version - fault in if not in
cache
+ if (function != null) {
+ return function;
+ }
+ ArrayList<byte[]> arrayList = new ArrayList<byte[]>(1);
+ arrayList.add(key);
+ List<PFunction> functions = buildFunctions(arrayList, region,
asOfTimeStamp);
+ if(functions != null) return functions.get(0);
+ // if not found then check if newer table already exists and
add delete marker for timestamp
--- End diff --
newer function?
> Support UDFs
> ------------
>
> Key: PHOENIX-538
> URL: https://issues.apache.org/jira/browse/PHOENIX-538
> Project: Phoenix
> Issue Type: Task
> Reporter: James Taylor
> Assignee: Rajeshbabu Chintaguntla
> Fix For: 5.0.0, 4.4.0
>
> Attachments: PHOENIX-538-wip.patch, PHOENIX-538_v1.patch,
> PHOENIX-538_v2.patch, PHOENIX-538_v3.patch, PHOENIX-538_v4.patch,
> PHOENIX-538_v5.patch, PHOENIX-538_v6.patch, PHOENIX-538_v6.patch
>
>
> Phoenix allows built-in functions to be added (as described
> [here](http://phoenix-hbase.blogspot.com/2013/04/how-to-add-your-own-built-in-function.html))
> with the restriction that they must be in the phoenix jar. We should improve
> on this and allow folks to declare new functions through a CREATE FUNCTION
> command like this:
> CREATE FUNCTION mdHash(anytype)
> RETURNS binary(16)
> LOCATION 'hdfs://path-to-my-jar' 'com.me.MDHashFunction'
> Since HBase supports loading jars dynamically, this would not be too
> difficult. The function implementation class would be required to extend our
> ScalarFunction base class. Here's how I could see it being implemented:
> * modify the phoenix grammar to support the new CREATE FUNCTION syntax
> * create a new UTFParseNode class to capture the parse state
> * add a new method to the MetaDataProtocol interface
> * add a new method in ConnectionQueryServices to invoke the MetaDataProtocol
> method
> * add a new method in MetaDataClient to invoke the ConnectionQueryServices
> method
> * persist functions in a new "SYSTEM.FUNCTION" table
> * add a new client-side representation to cache functions called PFunction
> * modify ColumnResolver to dynamically resolve a function in the same way we
> dynamically resolve and load a table
> * create and register a new ExpressionType called UDFExpression
> * at parse time, check for the function name in the built in list first (as
> is currently done), and if not found in the PFunction cache. If not found
> there, then use the new UDFExpression as a placeholder and have the
> ColumnResolver attempt to resolve it at compile time and throw an error if
> unsuccessful.
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