Continuations ignored for query

[ohadzeliger]

Summary:
Specifying maxRows:1 for recursive query has no effect
Steps To Reproduce:

1. Look at cte.yamsql
2. Add maxRows:1 to the test:
   • query: with c1 as (select col1, col2 from t1) select col1, col2 from c1
   • maxRows: 1
   • unorderedResult: [{COL1: 10, COL2: 1},
     {COL1: 10, COL2: 2},
     {COL1: 20, COL2: 6},
     {COL1: 20, COL2: 7}]
3. The test still passes

Note: The same happens for UPDATE queries.

[hatyo]

Please note the above query is a normal common table expression (not recursive), I tried to run it with the following configuration and it failed as expected:

- query: with c1 as (select col1, col2 from t1) select col1, col2 from c1
- maxRows: 1
- unorderedResult: [{COL1: 10, COL2: 1},
        {COL1: 10, COL2: 2},
        {COL1: 20, COL2: 6},
        {COL1: 20, COL2: 7}]

On the other hand, continuations are indeed not handled correctly in case of recursive CTE, the reason is that any user-defined row limit and skip set in the execution properties are ignored in the underlying recursive union cursor logic. I made a this PR #3111 to fix exactly that, and with it, continuations now work as expected for recursive CTEs. Example:

- query: with recursive c1 as (
            select id, parent from t1 where parent = -1
            union all
            select b.id, b.parent from c1 as a, t1 as b where a.id = b.parent) select id from c1
- maxRows: 1
- result: [{ID: 1}]
- result: [{ID: 10}]
- result: [{ID: 20}]
- result: [{ID: 40}]
- result: [{ID: 50}]
- result: [{ID: 70}]
- result: [{ID: 100}]
- result: [{ID: 210}]
- result: [{ID: 250}]
- result: []