Hi Julian, We have used calcite JDBC connection to run the queries and get the result set. Now we are struggling to get the planner object from JDBC connection and apply the custom rule to planner. Or to create the JDBC connection with custom planner.
Is there any tutorial available for using custom planner with JDBC connection? Regards, Harshit ________________________________ From: Julian Hyde <jhyde.apa...@gmail.com> Sent: Wednesday, September 18, 2024 12:14 PM To: dev@calcite.apache.org <dev@calcite.apache.org> Cc: Harshit Dwivedi <harshit.dwiv...@rockwellautomation.com>; Dipesh Sachdev <dipesh.sach...@rockwellautomation.com>; Thomas Keller <tkel...@ra.rockwell.com> Subject: EXTERNAL: Re: Questions Regarding Implementing LIMIT Clause Pushdown in Apache Calcite JDBC Driver [Use caution with links & attachments] FilterableTable and ProjectFikterTable were designed to make simple things simple but not go any further. It’s time to learn how to write planner rules. Julian > On Sep 17, 2024, at 22:42, Xiong Duan <xi...@apache.org> wrote: > > As far as I know, you may need to customize the implementation of > SortFilterableTable to support pushing limits. Like FilterableTable, > then you need to implement SortFilterTableScanRule to make sure can > generate the SortFilterableTable. > > Mihai Budiu <mbu...@gmail.com> 于2024年9月17日周二 16:37写道： >> >> Isn't limit stored in an order by clause, with potentially an empty list of >> fields to sort on? >> ________________________________ >> From: Vishal Kore <vishal.k...@rockwellautomation.com.INVALID> >> Sent: Tuesday, September 17, 2024 1:17:15 AM >> To: dev@calcite.apache.org <dev@calcite.apache.org> >> Cc: Harshit Dwivedi <harshit.dwiv...@rockwellautomation.com>; Dipesh Sachdev >> <dipesh.sach...@rockwellautomation.com>; Thomas Keller >> <tkel...@ra.rockwell.com> >> Subject: Questions Regarding Implementing LIMIT Clause Pushdown in Apache >> Calcite JDBC Driver >> >> Hi Devs, >> >> I am currently working on implementing (or extending) a JDBC driver for my >> backend storage system using Apache Calcite. I've implemented the >> FilterableTable interface, which allows pushing down WHERE clause filters to >> the backend using the scan(DataContext ctx, List<RexNode> filters) method. >> However, I'm struggling to push down the LIMIT clause to ensure that only >> the required number of records are retrieved from the backend. I cannot >> figure out how to access the LIMIT clause within the scan method. >> Could you please guide me on how to retrieve or implement the LIMIT clause >> in this context? >> Thanks for your assistance! >> Best regards, >> Vishal Kore
