Hi, kyungnam! On Mar 24, kyungnam wrote:
Hi, Sergei!
Thanks for your advice and I agree with you.
Accoring to your advice, It's not a good plan to pass some data to my plugin agent from sql_parse.cc because it needs to compile mariadb server.
So I hava a another concept.
Instead of put some code to sql_parse.cc, plugin collects a some data like below sample conceptual code.
I_List_iterator<THD> it(threads); while ((tmp_thd=it++)) { if ((tmp_thd->get_command() == COM_QUERY) ||(tmp_thd->get_command() == COM_STMT_EXECUTE) ) continue; char* sql = tmp_thd->query(); if(sql) { ... send_data(); } }
In this case, I though that it doesn't need to compile maria server, but it need to recompile whenever structure of THD is changed.
Yes, that's better. There are many plugins that access THD, even though THD is not officially a part of the plugin API.
Otherwise, if i hardcode directly into the server, can I contribute this community ?
Sure. You can contribute anything. The question is whether community will accept and use your contribution. I think the your contribution will be used more if it won't require anyone to recompile the server.
Additionally, you asked me about what information I want to collect.
I want to collect data like below.
* events_statements_current * events_stages_current * events_waits_current * events_statements_summary_by_digest
Oh, my. These are stored in the internal perfschema data structures. I don't think you can get them even from sql_parse.cc
These data easily collected by sql . but it's hard to collect by access memory.(THD or something else.)
I wonder if it is possible to collect these data without using pfs (or psi) data structure.
I doubt it. The only reasonable way to get this is to query performance schema. Either using SQL or with a lower-level handler interface. You can do either from your plugin. Regards, Sergei