The function connects to the database file db/globaltrends_db.sqlite
in the working directory. After connecting to the database connections to the
database tables (through dplyr::tbl) are created. Data from the tables
batch_keywords and batch_time are exported to the tibble
objects keywords_control, keywords_object, time_control,
and time_object.
start_db()The function exports the following objects to the package environment globaltrends_db:
globaltrends_db A DBIConnection object, as returned by
DBI::dbConnect(), connecting to the SQLite database in the working
directory
tbl_doi A remote data source pointing to the table data_doi in the connected SQLite database
tbl_control A remote data source pointing to the table data_control in the connected SQLite database
tbl_mapping A remote data source pointing to the table data_mapping in the connected SQLite database
tbl_object A remote data source pointing to the table data_object in the connected SQLite database
tbl_score A remote data source pointing to the table data_score in the connected SQLite database
countries A character vector containing ISO2 country codes of
countries that add at least 0.1\
us_states A character vector containing ISO2 regional codes of
US states
keywords_control A tibble containing keywords of control
batches
time_control A tibble containing times of control batches
keywords_object A tibble containing keywords of object batches
time_object A tibble containing times of control batches
keyword_synonyms A tibble containing synonymous keywords
SQLite databases only allow one writer at any instant in time. To run parallel downloads use one database for each download client and merge them once all downloads are complete.
initialize_db()
disconnect_db()