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Former Member
Aug 21, 2015 at 11:27 PM

Does Hana use nested loop Join on two column tables?

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We have two column tables - emp and dept.

There is an index on emp.ename.

There is an index on dept.deptno.

Below are the SQ

create column table emp

(

ename varchar2(30),

dept_no integer

)

create column table dept

(

deptno integer,

dname varchar2(30)

)

create index emp_i1 on emp(ename)

create index dept_i1 on dept(deptno)

select ename, dname

from emp, dept

where ename = 'john'

and dept.deptno = emp.dept_no

Below is the output when we explain plan using HANA studio.

The question here is

1. What is the join method used? we expect nested loop to be used

2. why do we see 10,000 as output instead of 1 for DEPT table.

3. Can we control Join method and Join order?

Please provide your suggestions.

@John Appleby

Regards,
Raj

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