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https://issues.apache.org/jira/browse/ARROW-10958?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Kouhei Sutou resolved ARROW-10958.
----------------------------------
Fix Version/s: 5.0.0
Resolution: Fixed
We can use Arrow Dataset API via Arrow GLib by ARROW-11205 and ARROW-11782.
The following code will work:
{code:c}
GADatasetParquetFileFormat *file_format =
gadataset_parquet_file_format_new();
GADatasetFileSystemDatasetFactory *factory =
gadataset_file_system_dataset_factory_new(GADATASET_FILE_FORMAT(file_format));
g_object_unref(file_format);
GError *error = NULL;
gadataset_file_system_dataset_factory_set_file_system_uri(factory,
"file:///tmp/a.parquet", &error);
GADataset *dataset =
gadataset_dataset_factory_finish(GADATASET_DATASET_FACTORY(factory));
g_object_unref(factory);
GArrowTable *table = gadataset_dataset_to_table(dataset, &error);
g_object_urnef(dataset);
{code}
> [GLib] "Nested data conversions not implemented" through glib, but not
> through pyarrow
> --------------------------------------------------------------------------------------
>
> Key: ARROW-10958
> URL: https://issues.apache.org/jira/browse/ARROW-10958
> Project: Apache Arrow
> Issue Type: Bug
> Components: GLib
> Affects Versions: 2.0.0
> Environment: macOS Catalina 10.15.7
> Reporter: Samay Kapadia
> Assignee: Kouhei Sutou
> Priority: Major
> Fix For: 5.0.0
>
>
> Hey all,
> For some context, I am trying to use Arrow's GLib interface through Julia; I
> have a sense that I can speedup by pandas workflows by using Julia and Apache
> Arrow.
> I have a 1.7GB parquet file that can be read in about 20s by using pyarrow's
> parquet reader
> {code:java}
> pq.read_table(path)
> {code}
> I've tried to do the same thing through the GLib interface in Julia, but I
> see this error instead :(
> {code:python}
> [parquet][arrow][file-reader][read-table]: NotImplemented: Nested data
> conversions not implemented for chunked array outputs
> {code}
> Arrow was installed using {{brew install apache-arrow-glib}} and it installed
> version 2.0.0
> Here's my Julia code:
> {code:python}
> using Pkg
> Pkg.add("Gtk")
> using Gtk.GLib
> using Gtk
> path = "..." # contains columns that are lists of strings
> struct _GParquetArrowFileReader
> parent_instance::Cint
> end
> const GParquetArrowFileReader = _GParquetArrowFileReaderstruct
> _GParquetArrowFileReaderClass
> parent_class::Cint
> end
> const GParquetArrowFileReaderClass = _GParquetArrowFileReaderClass
> struct _GArrowTable
> parent_instance::Cint
> end
> const GArrowTable = _GArrowTable
> struct _GArrowTableClass
> parent_class::Cint
> end
> const GArrowTableClass = _GArrowTableClass
> function
> parquet_arrow_file_reader_new_path(path::String)::Ptr{GParquetArrowFileReader}
> ret::Ptr{GParquetArrowFileReader} = 0
> GError() do error_check
> ret = ccall(
> (:gparquet_arrow_file_reader_new_path,
> "/usr/local/Cellar/apache-arrow-glib/2.0.0/lib/libparquet-glib.200"),
> Ptr{GParquetArrowFileReader},
> (Ptr{UInt8}, Ptr{Ptr{GError}}),
> Gtk.bytestring(path), error_check
> )
> ret != 0
> end
> ret
> end
> function
> parquet_arrow_file_reader_read_table(reader::Ptr{GParquetArrowFileReader})::Ptr{GArrowTable}
> ret::Ptr{GArrowTable} = 0
> GError() do error_check
> ret = ccall(
> (:gparquet_arrow_file_reader_read_table,
> "/usr/local/Cellar/apache-arrow-glib/2.0.0/lib/libparquet-glib.200"),
> Ptr{GParquetArrowFileReader},
> (Ptr{GParquetArrowFileReader}, Ptr{Ptr{GError}}),
> reader, error_check
> )
> ret != 0
> end
> ret
> end
> reader = parquet_arrow_file_reader_new_path(path)
> tbl = parquet_arrow_file_reader_read_table(reader)
> {code}
> Am I doing something wrong or is there a behavior discrepancy between pyarrow
> and glib?
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