[
https://issues.apache.org/jira/browse/CALCITE-529?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14245865#comment-14245865
]
Julian Hyde commented on CALCITE-529:
-------------------------------------
setObject is only allowed if the type is serializable or there is an entry in
the type-mapping for it. Otherwise there is no way to get it from the JDBC
client to the server. Same kind of restrictions I am talking about.
I'm not talking about implementor's stash. Just create a UDF:
{code}
public StashUdf {
public Object apply(String handle) {
return MAP.get(handle);
}
public static String register(Object o) {
String handle = "k" + MAP.size();
MAP.put(handle, o);
return handle;
}
}
{code}
In whatever code you want to reference an object, call StashUdf.register to get
a handle, then generate a RexCall to StashUdf with that handle. {{Stash("k0")}}
will evaluate to your object.
> Allow to pass java object via rexBuilder.makeLiteral()
> ------------------------------------------------------
>
> Key: CALCITE-529
> URL: https://issues.apache.org/jira/browse/CALCITE-529
> Project: Calcite
> Issue Type: Bug
> Affects Versions: 1.0.0-incubating
> Reporter: Vladimir Sitnikov
> Assignee: Julian Hyde
> Labels: newbie
>
> Motivation: Rex is simpler that linq4j.
> For instance,
> 1) Sometimes it is easier to create a {{ProjectRel}} rather than lower the
> expression to low-level linq4j
> 2) XXXToEnumerableRule are easier to accomplish via TableFunctionScan. This
> allows to express the call via Rex and skip linq4j completely.
> For example:
> https://github.com/vlsi/mat-calcite-plugin/blob/master/MatCalcitePlugin/src/com/github/vlsi/mat/optiq/rules/InstanceAccessByClassIdRule.java#L43
> The problem is to pass non-literal java object to enumerable/interpreter
> conventions.
> For enumerable the implementation can use stash. For interpreter it can use
> the value as is, etc.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
