Returned number of rows inserted is incorrect

[scsmithr]

Description

> select count(*) from ctas3;
┌─────────────────┐
│ COUNT(UInt8(1)) │
│ ──              │
│ Int64           │
╞═════════════════╡
│ 1000            │
└─────────────────┘
> insert into ctas3 select * exclude registration_dttm from './testdata/parquet/userdata1.parquet';
Inserted 0 rows
> select count(*) from ctas3;
┌─────────────────┐
│ COUNT(UInt8(1)) │
│ ──              │
│ Int64           │
╞═════════════════╡
│ 2000            │
└─────────────────┘

[adhish20]

delta-rs does not currently support output metrics for create and insert operations. Open issue : delta-io/delta-rs#1152

We are just defaulting to 0 while trying to get the output_rows from ExecutionPlan right now

[scsmithr]

This doesn't feel like a delta-rs issue. We're calculating number of rows inserted by reading the metrics from the input source: https://github.com/glaredb/glaredb/blob/863ea8670ccfc80cc88aac3d5a7c1f39b8169652/crates/datasources/src/native/insert.rs#L121-L124

We can see that it works for some sources, and not for others:

> create table t (a int);
Table created
> insert into t select * from generate_series(1, 3);
Inserted 3 rows

> create table ctas2 as select * exclude registration_dttm from './testdata/parquet/userdata1.parquet';
Table created
> insert into ctas2 select * exclude registration_dttm from './testdata/parquet/userdata1.parquet';
Inserted 0 rows

But interestingly this works correctly for temp tables:

> create temp table ctas2 as select * exclude registration_dttm from './testdata/parquet/userdata1.parquet';
Table created
> insert into ctas2 select * exclude registration_dttm from './testdata/parquet/userdata1.parquet';
Inserted 1000 rows