# * <tt>:database</tt> -- The name of the database. No default, must be provided.
# * <tt>:schema_search_path</tt> -- An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the <tt>:schema_order</tt> option.
# * <tt>:encoding</tt> -- An optional client encoding that is used in a SET client_encoding TO <encoding> call on the connection.
# * <tt>:min_messages</tt> -- An optional client min messages that is used in a SET client_min_messages TO <min_messages> call on the connection.
# * <tt>:allow_concurrency</tt> -- If true, use async query methods so Ruby threads don't deadlock; otherwise, use blocking query methods.
# * <tt>:host</tt> - Defaults to "localhost".
# * <tt>:port</tt> - Defaults to 5432.
# * <tt>:username</tt> - Defaults to nothing.
# * <tt>:password</tt> - Defaults to nothing.
# * <tt>:database</tt> - The name of the database. No default, must be provided.
# * <tt>:schema_search_path</tt> - An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the <tt>:schema_order</tt> option.
# * <tt>:encoding</tt> - An optional client encoding that is used in a <tt>SET client_encoding TO <encoding></tt> call on the connection.
# * <tt>:min_messages</tt> - An optional client min messages that is used in a <tt>SET client_min_messages TO <min_messages></tt> call on the connection.
# * <tt>:allow_concurrency</tt> - If true, use async query methods so Ruby threads don't deadlock; otherwise, use blocking query methods.
classPostgreSQLAdapter<AbstractAdapter
# Returns 'PostgreSQL' as adapter name for identification purposes.