Hi Liya,
Please see below , I have a query as given below
SELECT t_1.ID FROM USERS t_1 where NAME = 'HELLO';
Now I know that I have to fetch two columns from my columnar database i.e.
ID, Name, so need to pass these parameters in my custom Table Scan.
But when I convert the LogicalTableScan to my custom Table scan I do not
have that information, please see the tree below, in the Logical Table Scan
the Input is null, I was hoping that I will have the columns in the
LogicalTableScan, The question is what do I need to do in Calcite to pass
that information to the LogicalTableScan or in my physical operator. The
way I have found is that I create a Rule like ProjectFilterTableScan rule
and then extract what information I need. Is there a better way to do this?
-----------------Logical JSON Plan --------------------
> {
> "rels": [
> {
> "id": "0",
> "relOp": "LogicalTableScan",
> "table": [
> "USERS"
> ],
> "inputs": []
> },
> {
> "id": "1",
> "relOp": "LogicalFilter",
> "condition": {
> "op": {
> "name": "=",
> "kind": "EQUALS",
> "syntax": "BINARY"
> },
> "operands": [
> {
> "op": {
> "name": "CAST",
> "kind": "CAST",
> "syntax": "SPECIAL"
> },
> "operands": [
> {
> "input": 1,
> "name": "$1"
> }
> ],
> "type": {
> "type": "CHAR",
> "nullable": true,
> "precision": 5
> }
> },
> {
> "literal": "HELLO",
> "type": {
> "type": "CHAR",
> "nullable": false,
> "precision": 5
> }
> }
> ]
> }
> },
> {
> "id": "2",
> "relOp": "LogicalProject",
> "fields": [
> "ID"
> ],
> "exprs": [
> {
> "input": 0,
> "name": "$0"
> }
> ]
> }
> ]
> }
>
>> -----------------------------------------------------------
>
>
Thanks and regards
Bhavya
On Fri, Dec 18, 2020 at 11:54 AM Fan Liya <[email protected]> wrote:
> Hi Bhavya,
>
> Sorry I do not understand your question. Why is it difficult to pass sth.
> to child operators?
>
> Best,
> Liya Fan
>
>
> On Fri, Dec 18, 2020 at 12:38 PM Bhavya Aggarwal <[email protected]>
> wrote:
>
> > Hi Liya,
> >
> > Actually the question is how to pass the projection columns to Table Scan
> > as right now in the LogicalTableScan there are no projection columns
> being
> > passed so when I am trying to create my custom JSON , I do not have those
> > projected columns or columns that are being used in the query. I want to
> > understand what is the calcite mechanism for passing it to child
> operators
> > without using Rules as it will be a lot of rule that we need to
> implement.
> >
> > Thanks and Regards
> > Bhavya
> >
> > On Fri, Dec 18, 2020 at 9:47 AM Fan Liya <[email protected]> wrote:
> >
> > > Hi Bhavya,
> > >
> > > It seems the problem is that the json format provided by Calcite does
> not
> > > include properties specific to your operator?
> > > If so, I think you can override RelNode#explainTerms in your operator
> to
> > > attach the properties.
> > >
> > > Best,
> > > Liya Fan
> > >
> > > On Thu, Dec 17, 2020 at 10:45 PM Bhavya Aggarwal <[email protected]>
> > > wrote:
> > >
> > > > Please let me know if we have an example for writing a custom visitor
> > > that
> > > > I can use. I see a RelVisitor class that I can extend but how to make
> > it
> > > to
> > > > visit the specific Physical Operator.
> > > >
> > > > Thanks and Regards
> > > > Bhavya
> > > >
> > > > On Thu, Dec 17, 2020 at 7:43 PM Bhavya Aggarwal <[email protected]>
> > > > wrote:
> > > >
> > > > > Thanks,
> > > > >
> > > > > I tried using the RelJsonWriter and tried to add my custom
> > > implementation
> > > > > in the my custom Rel Nodes but I am not getting all the data in my
> > > child
> > > > > operators. We are trying to use Calcite for a columnar data and we
> > need
> > > > the
> > > > > information of the projections in the TableScan as well because we
> > need
> > > > to
> > > > > pass those projections to read specific columns but I am not able
> to
> > > find
> > > > > the projections in my Table scan. As per my understanding Calcite
> > > should
> > > > be
> > > > > passing this information as it is required for me reading the
> table.
> > > > Please
> > > > > let me know if I need to do something special to get that
> information
> > > in
> > > > > the child operator.
> > > > >
> > > > > Regards
> > > > > Bhavya
> > > > >
> > > > > On Sun, Dec 13, 2020 at 11:32 PM Michael Mior <[email protected]>
> > > wrote:
> > > > >
> > > > >> That would likely be the best approach if you have some specific
> > JSON
> > > > >> format you're trying to generate. If you're happy with a JSON
> format
> > > > >> defined by Calcite, you can look at RelJsonWriter.
> > > > >>
> > > > >> --
> > > > >> Michael Mior
> > > > >> [email protected]
> > > > >>
> > > > >> Le dim. 13 déc. 2020 à 05:36, Muhammad Gelbana <
> [email protected]
> > >
> > > a
> > > > >> écrit :
> > > > >> >
> > > > >> > I would use a visitor to traverse the optimized/physical plan.
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> > On Sun, Dec 13, 2020 at 6:42 AM Bhavya Aggarwal <
> > [email protected]
> > > >
> > > > >> wrote:
> > > > >> >
> > > > >> > > Hi All,
> > > > >> > >
> > > > >> > > We need to generate a JSON object for the physical execution
> > tree
> > > > >> that has
> > > > >> > > been created. Is there an option in Calcite that we can use to
> > do
> > > > >> this. I
> > > > >> > > am not sure what is the right approach to do it. Please let me
> > > know
> > > > if
> > > > >> > > there are different ways to achieve this.
> > > > >> > >
> > > > >> > > Regards
> > > > >> > > Bhavya
> > > > >> > >
> > > > >> > > --
> > > > >> > > Your feedback matters - At Knoldus we aim to be very
> > professional
> > > in
> > > > >> our
> > > > >> > > quality of work, commitment to results, and proactive
> > > communication.
> > > > >> If
> > > > >> > > you
> > > > >> > > feel otherwise please share your feedback
> > > > >> > > <https://forms.gle/Ax1Te1DDpirAQuQ8A> and we would work on
> it.
> > > > >> > >
> > > > >>
> > > > >
> > > > >
> > > > > --
> > > > > *Bhavya Aggarwal*
> > > > > CTO & Partner
> > > > > Knoldus Inc. <http://www.knoldus.com/>
> > > > > +91-9910483067
> > > > > Canada - USA - India - Singapore
> > > > > <https://in.linkedin.com/company/knoldus> <
> > > https://twitter.com/Knolspeak
> > > > >
> > > > > <https://www.facebook.com/KnoldusSoftware/> <
> > https://blog.knoldus.com/
> > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > *Bhavya Aggarwal*
> > > > CTO & Partner
> > > > Knoldus Inc. <http://www.knoldus.com/>
> > > > +91-9910483067
> > > > Canada - USA - India - Singapore
> > > > <https://in.linkedin.com/company/knoldus> <
> > https://twitter.com/Knolspeak
> > > >
> > > > <https://www.facebook.com/KnoldusSoftware/> <
> https://blog.knoldus.com/
> > >
> > > >
> > > > --
> > > > Your feedback matters - At Knoldus we aim to be very professional in
> > our
> > > > quality of work, commitment to results, and proactive communication.
> If
> > > > you
> > > > feel otherwise please share your feedback
> > > > <https://forms.gle/Ax1Te1DDpirAQuQ8A> and we would work on it.
> > > >
> > >
> >
> >
> > --
> > *Bhavya Aggarwal*
> > CTO & Partner
> > Knoldus Inc. <http://www.knoldus.com/>
> > +91-9910483067
> > Canada - USA - India - Singapore
> > <https://in.linkedin.com/company/knoldus> <https://twitter.com/Knolspeak
> >
> > <https://www.facebook.com/KnoldusSoftware/> <https://blog.knoldus.com/>
> >
> > --
> > Your feedback matters - At Knoldus we aim to be very professional in our
> > quality of work, commitment to results, and proactive communication. If
> > you
> > feel otherwise please share your feedback
> > <https://forms.gle/Ax1Te1DDpirAQuQ8A> and we would work on it.
> >
>
--
*Bhavya Aggarwal*
CTO & Partner
Knoldus Inc. <http://www.knoldus.com/>
+91-9910483067
Canada - USA - India - Singapore
<https://in.linkedin.com/company/knoldus> <https://twitter.com/Knolspeak>
<https://www.facebook.com/KnoldusSoftware/> <https://blog.knoldus.com/>
--
Your feedback matters - At Knoldus we aim to be very professional in our
quality of work, commitment to results, and proactive communication. If you
feel otherwise please share your feedback
<https://forms.gle/Ax1Te1DDpirAQuQ8A> and we would work on it.
