sqlite_to_parquet {parquetize}

Convert a sqlite file to parquet format

Description

This function allows to convert a table from a sqlite file to parquet format.
The following extensions are supported : "db","sdb","sqlite","db3","s3db","sqlite3","sl3","db2","s2db","sqlite2","sl2".

Two conversions possibilities are offered :

• Convert to a single parquet file. Argument 'path_to_parquet' must then be used;

• Convert to a partitioned parquet file. Additionnal arguments 'partition' and 'partitioning' must then be used;

Usage

sqlite_to_parquet(
  path_to_file,
  table_in_sqlite,
  path_to_parquet,
  partition = "no",
  compression = "snappy",
  compression_level = NULL,
  ...
)

Arguments

path_to_file

String that indicates the path to the input file (don't forget the extension).

table_in_sqlite

string that indicates the name of the table to convert in the sqlite file

path_to_parquet

String that indicates the path to the directory where the parquet files will be stored.

partition

String ("yes" or "no" - by default) that indicates whether you want to create a partitioned parquet file. If "yes", '"partitioning"' argument must be filled in. In this case, a folder will be created for each modality of the variable filled in '"partitioning"'. Be careful, this argument can not be "yes" if 'max_memory' or 'max_rows' argument are not NULL.

compression

compression algorithm. Default "snappy".

compression_level

compression level. Meaning depends on compression algorithm.

...

additional format-specific arguments, see arrow::write_parquet() and arrow::write_dataset() for more informations.

Value

A parquet file, invisibly

Examples

# Conversion from a local sqlite file to a single parquet file :

sqlite_to_parquet(
  path_to_file = system.file("extdata","iris.sqlite",package = "parquetize"),
  table_in_sqlite = "iris",
  path_to_parquet = tempfile(fileext = ".parquet")
)

# Conversion from a local sqlite file to a partitioned parquet file  :

sqlite_to_parquet(
  path_to_file = system.file("extdata","iris.sqlite",package = "parquetize"),
  table_in_sqlite = "iris",
  path_to_parquet = tempfile(),
  partition = "yes",
  partitioning =  c("Species")
)