Hi,

I do not understand why

set planonly;
with recursive
CTE_CNT1 as (select 0 as I
from RDB$DATABASE
union all select I + 1
from CTE_CNT1
where I < 9),

CTE_CNT2 as (select I, 0 as J
from CTE_CNT1
union all select J * 10 + c1.I, c2.J + 1
from CTE_CNT1 c1
join CTE_CNT2 c2 on c2.J < 10)

select I from CTE_CNT2;

fails with:
Statement failed, SQLSTATE = 42S22
Dynamic SQL Error
-SQL error code = -206
-Column unknown
-C2.J
-At line 14, column 15

while the similar

with recursive
CTE_CNT1 as (select 0 as I
from RDB$DATABASE
union all select I + 1
from CTE_CNT1
where I < 9),

CTE_CNT2 as (select 0 as I, 0 as J
from RDB$DATABASE
union all select J * 10 + c1.I, c2.J + 1
from CTE_CNT1 c1
join CTE_CNT2 c2 on c2.J < 10)

select I from CTE_CNT2;

succeds with

PLAN (CTE_CNT2 RDB$DATABASE NATURAL, CTE_CNT2 CTE_CNT1 RDB$DATABASE
NATURAL, JOIN ())

Frank

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