[CALCITE-4144] Reduce code generation and class loading overhead when getScalar in JaninoRexCompiler.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.24.0
• Component/s: core
• Labels: cache scalar

Environment

version: calcite-core 1.24
mode: filterableTable

• Assignee: Unassigned
• Reporter: zhangchenghui
• Created: 27/Jul/20 14:48
• Updated: 03/Aug/20 09:09

Description

I used the FilterableTable mode in the project, but I found that the query was particularly slow. I used the JProfile tool to troubleshoot the thread time-consuming place, and then through the debug, I found that each request took two places:
1、org.apache.calcite.adapter.enumerable.EnumerableInterpretable#getBindable

This place optimizes the cache settings by setting the cache size.
2、org.apache.calcite.interpreter.JaninoRexCompiler#baz

But this place is not cached, and a new expression string is used every time to create it through reflection.
JProfile tool time consumption:

I originally wanted to add a layer of cache here, but found that the expressions generated each time are different, as follows:

So you can't use the getBindable method to directly add cache.
Is there anything you can optimize here? For example, can you generate a template class in advance, and then generate different objects through different parameter values?

Bring tea to the boss!
Looking forward to your reply!

Issue Links

• is related to: CALCITE-2703 Reduce code generation and class loading overhead when executing queries in the EnumerableConvention