Hoisting literals

[Homer <lo...@gmail.com>]

Hi,

I am wondering if this is something that has already in calcite but I 
cannot seem to find it.

Imagine that it is common to run a large number of very similar machine 
generated queries that just change the literals in the sql query

for example (the real queries would be much more complex)

Select * from emp where empno = 1
Select * from emp where empno = 2
...

etc

The plan that is likely being generated for these kind of queries is 
going to be very much the same each time, so to save some time, I would 
like to recognize that the literals are all that have changed in a query 
and use the previously optimized execution plan and just replace the 
literals?

Is there anything I can leverage in calcite (or is the functionality 
already there?) for this kind of thing?

thanks,
Homer

Re: Hoisting literals

[Julian Hyde <jh...@apache.org>]

It isn’t, but it would be really useful. I’ve logged https://issues.apache.org/jira/browse/CALCITE-963 <https://issues.apache.org/jira/browse/CALCITE-963> with an outline of how it could be implemented.

Julian


> On Nov 11, 2015, at 9:33 AM, Homer <lo...@gmail.com> wrote:
> 
> Hi,
> 
> I am wondering if this is something that has already in calcite but I cannot seem to find it.
> 
> Imagine that it is common to run a large number of very similar machine generated queries that just change the literals in the sql query
> 
> for example (the real queries would be much more complex)
> 
> Select * from emp where empno = 1
> Select * from emp where empno = 2
> ...
> 
> etc
> 
> The plan that is likely being generated for these kind of queries is going to be very much the same each time, so to save some time, I would like to recognize that the literals are all that have changed in a query and use the previously optimized execution plan and just replace the literals?
> 
> Is there anything I can leverage in calcite (or is the functionality already there?) for this kind of thing?
> 
> thanks,
> Homer