parquet-cli/README.md

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## Building

You can build this project using maven:

```
./mvnw clean install -DskipTests
```


## Running

The build produces a shaded Jar that can be run using the `hadoop` command:

```
hadoop jar parquet-cli-1.12.3-runtime.jar org.apache.parquet.cli.Main
```

For a shorter command-line invocation, add an alias to your shell like this:

```
alias parquet="hadoop jar /path/to/parquet-cli-1.12.3-runtime.jar org.apache.parquet.cli.Main --dollar-zero parquet"
```

### Running without Hadoop

To run from the target directory instead of using the `hadoop` command, first copy the dependencies to a folder:

```
./mvnw dependency:copy-dependencies
```

Then, run the command-line and add `target/dependencies/*` to the classpath:

```
java -cp 'target/parquet-cli-1.12.3.jar:target/dependency/*' org.apache.parquet.cli.Main
```

Note that you shouldn't include the runtime jar used above into the classpath in this case.
In that jar, the `org.apache.avro package` is relocated for avoiding conflict with Hadoop's one.
That relocation changes method signatures, so it can cause `NoSuchMethodError` depending on the class loading order.
See PARQUET-2142 for details.


### Help

The `parquet` tool includes help for the included commands:

```
parquet help
```
```
Usage: parquet [options] [command] [command options]

  Options:

    -v, --verbose, --debug
        Print extra debugging information

  Commands:

    help
        Retrieves details on the functions of other commands
    meta
        Print a Parquet file's metadata
    pages
        Print page summaries for a Parquet file
    dictionary
        Print dictionaries for a Parquet column
    check-stats
        Check Parquet files for corrupt page and column stats (PARQUET-251)
    schema
        Print the Avro schema for a file
    csv-schema
        Build a schema from a CSV data sample
    convert-csv
        Create a file from CSV data
    convert
        Create a Parquet file from a data file
    to-avro
        Create an Avro file from a data file
    cat
        Print the first N records from a file
    head
        Print the first N records from a file
    column-index
        Prints the column and offset indexes of a Parquet file
    column-size
        Print the column sizes of a parquet file
    prune
        (Deprecated: will be removed in 2.0.0, use rewrite command instead) Prune column(s) in a Parquet file and save it to a new file. The columns left are not changed.
    trans-compression
        (Deprecated: will be removed in 2.0.0, use rewrite command instead) Translate the compression from one to another (It doesn't support bloom filter feature yet).
    masking
        (Deprecated: will be removed in 2.0.0, use rewrite command instead) Replace columns with masked values and write to a new Parquet file
    footer
        Print the Parquet file footer in json format
    bloom-filter
        Check bloom filters for a Parquet column
    scan
        Scan all records from a file
    rewrite
        Rewrite one or more Parquet files to a new Parquet file
    size-stats
        Print size statistics for a Parquet file

  Examples:

    # print information for create
    parquet help meta

  See 'parquet help <command>' for more information on a specific command.
```