docs/source/user-guide/parquet.md

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# Parquet

DataFusion Java reads Parquet through two entry points on `SessionContext`:
`registerParquet` to expose a file as a named table, and `readParquet` to
get a `DataFrame` directly.

## Register a table

```java
ctx.registerParquet("orders", "/path/to/orders.parquet");

try (DataFrame df = ctx.sql("SELECT * FROM orders LIMIT 10")) {
    df.show();
}
```

The file's footer is read at registration time. The table remains in the
catalog for the lifetime of the `SessionContext`.

## Read a DataFrame directly

```java
try (DataFrame df = ctx.readParquet("/path/to/orders.parquet")) {
    df.show();
}
```

`readParquet` skips the catalog and hands back a `DataFrame` straight
away.

## ParquetReadOptions

Both entry points accept a `ParquetReadOptions` to tune the underlying
read. Construct one directly and chain setters:

```java
ParquetReadOptions opts = new ParquetReadOptions()
    .fileExtension(".parquet");

ctx.registerParquet("orders", "/path/to/orders.parquet", opts);
// or
try (DataFrame df = ctx.readParquet("/path/to/orders.parquet", opts)) {
    df.show();
}
```

The supported setters track what DataFusion exposes on its Rust
`ParquetReadOptions` builder. Inspect the class on the Java side for the
exact setters available in the version you are using.