Query leads to endless loop (because of Optimizer?)

[tcm-marcel]

Running TPC-H Q13 leads to an endless loop in peloton. I tried to follow the execution path and it seems to me that the optimizer runs in infinitely many tasks and the actual execution never starts. However, I am not familiar with this part of peloton.

TPC-H Q13 (includes creating schema)

```sql CREATE TABLE nation ( n_nationkey INTEGER NOT NULL, n_name CHAR(25) NOT NULL, n_regionkey INTEGER NOT NULL, n_comment VARCHAR(152)); CREATE TABLE region ( r_regionkey INTEGER NOT NULL, r_name CHAR(25) NOT NULL, r_comment VARCHAR(152)); CREATE TABLE part ( p_partkey INTEGER NOT NULL, p_name VARCHAR(55) NOT NULL, p_mfgr CHAR(25) NOT NULL, p_brand CHAR(10) NOT NULL, p_type VARCHAR(25) NOT NULL, p_size INTEGER NOT NULL, p_container CHAR(10) NOT NULL, p_retailprice DECIMAL(15,2) NOT NULL, p_comment VARCHAR(23) NOT NULL ); CREATE TABLE supplier ( s_suppkey INTEGER NOT NULL, s_name CHAR(25) NOT NULL, s_address VARCHAR(40) NOT NULL, s_nationkey INTEGER NOT NULL, s_phone CHAR(15) NOT NULL, s_acctbal DECIMAL(15,2) NOT NULL, s_comment VARCHAR(101) NOT NULL); CREATE TABLE partsupp ( ps_partkey INTEGER NOT NULL, ps_suppkey INTEGER NOT NULL, ps_availqty INTEGER NOT NULL, ps_supplycost DECIMAL(15,2) NOT NULL, ps_comment VARCHAR(199) NOT NULL ); CREATE TABLE customer ( c_custkey INTEGER NOT NULL, c_name VARCHAR(25) NOT NULL, c_address VARCHAR(40) NOT NULL, c_nationkey INTEGER NOT NULL, c_phone CHAR(15) NOT NULL, c_acctbal DECIMAL(15,2) NOT NULL, c_mktsegment CHAR(10) NOT NULL, c_comment VARCHAR(117) NOT NULL); CREATE TABLE orders ( o_orderkey INTEGER NOT NULL, o_custkey INTEGER NOT NULL, o_orderstatus CHAR(1) NOT NULL, o_totalprice DECIMAL(15,2) NOT NULL, o_orderdate DATE NOT NULL, o_orderpriority CHAR(15) NOT NULL, o_clerk CHAR(15) NOT NULL, o_shippriority INTEGER NOT NULL, o_comment VARCHAR(79) NOT NULL); CREATE TABLE lineitem ( l_orderkey INTEGER NOT NULL, l_partkey INTEGER NOT NULL, l_suppkey INTEGER NOT NULL, l_linenumber INTEGER NOT NULL, l_quantity DECIMAL(15,2) NOT NULL, l_extendedprice DECIMAL(15,2) NOT NULL, l_discount DECIMAL(15,2) NOT NULL, l_tax DECIMAL(15,2) NOT NULL, l_returnflag CHAR(1) NOT NULL, l_linestatus CHAR(1) NOT NULL, l_shipdate DATE NOT NULL, l_commitdate DATE NOT NULL, l_receiptdate DATE NOT NULL, l_shipinstruct CHAR(25) NOT NULL, l_shipmode CHAR(10) NOT NULL, l_comment VARCHAR(44) NOT NULL); select c_count, count(*) as custdist from ( select c_custkey, count(o_orderkey) as c_count from customer left outer join orders on c_custkey = o_custkey and o_comment not like '%special%deposits%' group by c_custkey ) as c_orders group by c_count order by count(*) desc, c_count desc; ```

[tcm-marcel]

@chenboy can you take a look at this?

[GustavoAngulo]

@tcm-marcel The loop is caused because this query contains a Left Outer Join. A group in 15721 is working on implementing outer joins in the optimizer (#1280) so it should hopefully be fixed soon. I'll keep the issue open for now.

For the future though we should probably throw an exception for unimplemented SQL functions in the optimizer instead of looping.

[tcm-marcel]

Great, thank you!