ceph/src/arrow/ruby/red-parquet/README.md

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  19
  20 # Red Parquet - Apache Parquet Ruby
  21
  22 Red Parquet is the Ruby bindings of Apache Parquet. Red Parquet is based on GObject Introspection.
  23
  24 [Apache Parquet](https://parquet.apache.org/) is a columnar storage format.
  25
  26 [GObject Introspection](https://wiki.gnome.org/action/show/Projects/GObjectIntrospection) is a middleware for language bindings of C library. GObject Introspection can generate language bindings automatically at runtime.
  27
  28 Red Parquet uses [Apache Parquet GLib](https://github.com/apache/arrow/tree/master/c_glib/parquet-glib) and [gobject-introspection gem](https://rubygems.org/gems/gobject-introspection) to generate Ruby bindings of Apache Parquet.
  29
  30 Apache Parquet GLib is a C wrapper for [Apache Parquet C++](https://github.com/apache/arrow/tree/master/cpp/src/parquet). GObject Introspection can't use Apache Parquet C++ directly. Apache Parquet GLib is a bridge between Apache Parquet C++ and GObject Introspection.
  31
  32 gobject-introspection gem is a Ruby bindings of GObject Introspection. Red Parquet uses GObject Introspection via gobject-introspection gem.
  33
  34 ## Install
  35
  36 Install Apache Parquet GLib before install Red Parquet. See [Apache Arrow install document](https://arrow.apache.org/install/) for details.
  37
  38 Install Red Parquet after you install Apache Parquet GLib:
  39
  40 ```text
  41 % gem install red-parquet
  42 ```
  43
  44 ## Usage
  45
  46 ```ruby
  47 require "parquet"
  48
  49 table = Arrow::Table.load("/dev/shm/data.parquet")
  50 # Process data in table
  51 table.save("/dev/shm/data-processed.parquet")
  52 ```