Interaction of operators in the kernel.

Xu,Wenjian zeroxwj at
Wed Jul 8 11:42:11 CEST 2015


My objective is to investigate that, given an SPJ query, how are BATs
*physically* processed (changed) among relational algebra operators (e.g.,
select, join). I do not care about how query is translated into execution
plan in MAL, what I care is the interaction of operators in the kernel
(aka., gdk) .

My current plan is to add some debug information in those operators (e.g.,
functions in src/gdk_join.c, src/gdk_select.c) and re-compile the system.
Then, I will pose an SPJ query (through console) and check the system log
to see how those operators are invoked in sequence.

But this method seems inefficient and I would like to ask if there are any
alternatives, for example, is it possible to debug the system
*step-by-step* given an input query (or its logical query plan).

Thank you very much for any kind help.

Best regards,
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the developers-list mailing list