Hi, Sriram!

First: please don't forget to cc: the list maria-developers@lists.launchpad.net
Thank you.

On Mar 18, sriram patil wrote:
> Hi Sergei,
>
> I was going through the source code and was able to figure out the
> flow of query execution and major functions through which a query goes
> before execution.
>
> The query execution majorly dwells in the "sql" directory of the
> source code. So, I think I will have to make changes in the following
> files throughout the project,
>
>    - sql_parse.cc (do_command, dispatch_command, mysql_execute_command)

Yes. And also sql_yacc.yy - to extend the parser.
And the implementation of these commands, for example, sql_acl.cc for
CREATE/DROP USER, sql_trigger.cc for CREATE/DROP TRIGGER, etc.

>    - sql_prepare.cc (Prepared_statement::execute_loop,
>    Prepared_statement::execute)

No, hopefully, this will work automatically.

> What I am not sure about is will I have to create a handler for some of
> these commands?

You are not creating new commands

> And will lower level storage engine code changes required?

I don't think so.

> > > I am interested to work on "CREATE OR REPLACE, CREATE IF NOT EXISTS, and
> > > DROP IF EXISTS" project as part of GSOC 2014. I want to apply my subject
> > > knowledge at a bigger level which will also give me an idea about the
> > > practical issues while implementing the features.
> > >
Regards,
Sergei