File: with_explain.test

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--echo # Verifying the CTE-specific output of EXPLAIN

create table t1(a int);
insert into t1 values(1),(2);

--echo # In JSON "materialized_from_subquery" for the 2 last references
--echo # points to 1st reference: no duplication. In TRADITIONAL,
--echo # The 2 last references are 1) not expanded (underlying tables
--echo # are not shown) 2) shown as <derivedN> where N is ID of 1st
--echo # reference. So users understand we have single materialization.

let $query=
with qn(a) as (select 1 from t1 limit 2)
select * from qn where qn.a=(select * from qn qn1 limit 1) ;

--skip_if_hypergraph  # Depends on the query plan.
eval explain format=json $query;
eval explain format=traditional $query;

let $query=
with qn as (select cast("x" as char(100)) as a from t1 limit 2)
select (select * from qn) from qn, qn qn1;

--skip_if_hypergraph  # Depends on the query plan.
eval explain format=json $query;
eval explain format=traditional $query;

--echo # Recursive query block has a mark:
--echo # "recursive":true in JSON, "Recursive" on its first table in
--echo # TRADITIONAL.

let $query=
with recursive qn as (select cast("x" as char(100)) as a from dual
                      union all
                      select concat("x",qn.a) from qn,t1 where
                      length(qn.a)<10)
select * from qn;

--skip_if_hypergraph  # Depends on the query plan.
eval explain format=json $query;
eval explain format=traditional $query;

drop table t1;