matthewmturner opened a new issue #1705:
URL: https://github.com/apache/arrow-datafusion/issues/1705
**Is your feature request related to a problem or challenge? Please describe
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I think that we can simplify creating a `ListingTable` by using some simple
inference and reasonable defaults for `ListingOptions` and `Schema`
**Describe the solution you'd like**
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I would like to update the signature to go from:
```
ListingTable::new(object_store: Arc<dyn ObjectStore>, table_path: String,
file_schema: SchemaRef, options: ListingOptions)
```
to
```
ListingTable::new(object_store: Arc<dyn ObjectStore>, table_path: String,
file_schema: Option<SchemaRef>, options: <ListingOptions>)
```
Then, we can look at the suffix of the `table_path` to infer a file type and
use that for the `format` and `file_extension` parameters of `ListingOptions`.
We could use the below as defaults for the other parameters:
```
let listing_options = ListingOptions {
format: Arc::new(ParquetFormat::default()), // derived from
ListingTable::new(table_path, ..)
collect_stat: true,
file_extension: "parquet".to_owned(), // derived from
ListingTable::new(table_path, ..)
target_partitions: num_cpus::get(),
table_partition_cols: vec![],
};
```
We could then use `listing_options` to create a `Schema`
```
// object_store from ListingTable::new(object_store, table_path, ..)
let resolved_schema = listing_options.infer_schema(object_store.clone(),
filename).await?;
```
The end result is a much simpler interface for creating tables.
Old
```
let filename = "data/alltypes_plain.snappy.parquet";
let listing_options = ListingOptions {
format: Arc::new(ParquetFormat::default()),
collect_stat: true,
file_extension: "parquet".to_owned(),
target_partitions: num_cpus::get(),
table_partition_cols: vec![],
};
let resolved_schema = listing_options
.infer_schema(object_store.clone(), filename)
.await?;
let table = ListingTable::new(
object_store,
filename.to_owned(),
resolved_schema,
listing_options,
);
```
New
```
let filename = "data/alltypes_plain.snappy.parquet";
let table = ListingTable::new(
object_store,
filename.to_owned(),
None,
None,
);
```
**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features
you've considered.
**Additional context**
Add any other context or screenshots about the feature request here.
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