db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Steen Jansdal <st...@jansdal.dk>
Subject Re: Derby Engine Architecture Qucik Overview
Date Mon, 16 Aug 2004 07:08:36 GMT
Daniel John Debrunner wrote:

> ~  1  parse using a parser generated by Javacc, results in a tree of
> query nodes

How is Javacc compared to ANTLR? How does the output from
Javacc look like? The output from ANTLR is a nice looking
readable java file that you can debug/single step through.
Note: I have absolutely no experience with Javacc.

> ~  4  generation of a Java class (directly to byte code)  to represent
> the statement plan
> ~  5  loading of the class and creation of an instance to represent that
> connection's state of the query
> The generated statement plan is cached and can be shared by multiple
> connections. DDL statements (e.g. CREATE TABLE use a common statement
> plan to avoid generation of a Java class file)

Interesting concept! How is the speed compared to a "normal"
plan executer? The first couple of times the statement plan
are executed, it would be interpreted. Only after a number
of executions the hot spot compiler will decide to compile
this into native code.

Is this concept also supported in J2ME?


Steen Jansdal

Derby is a project of the Apache Incubator (http://incubator.apache.org)

To unsubscribe, e-mail: derby-dev-unsubscribe@db.apache.org
For additional commands, e-mail: derby-dev-help@db.apache.org

View raw message