R/tdSpool.R

In tranlm/tdR: Teradata interaction and query package

# TODO: Function to grab Teradata spool usage.
#
# Author: Linh Tran
# Date: Mar 10, 2016
# Email: Linh_m_tran@apple.com
###############################################################################


#' @title tdSpool
#'
#' @description Queries Teradata for spool use. Can take a JDBC connection
#' object (\code{conn}) if provided. If no JDBC connection is provided, then
#' a connection is attempted using the \code{user}, and \code{password} provided.
#' If none is provided, then tries to locate a connection object (\code{conn})
#' in the global environment.
#'
#' If a connection profile (e.g. username, password, etc.) is provided, then
#' an attempt is made to connect to Teradata. Once the query is run, the
#' connection is then closed. If a connection object (\code{conn}) is provided
#' to the function (or one is found globally), then the connection remains
#' open.
#'
#' @param user Username to grab CPU use from. Defaults to the \code{username}
#' used in the Teradata connection.
#' @param ... Optional connection settings.
#'
#' @return A \code{data.frame} object is returned with all of the Teradata
#' spool information.
#'
#' @examples
#' ## NOT RUN ##
#' ## Connect to default data warehouse and data base
#' # tdSpool(<username>, <password>)
#'
#' ## Runs query using a separately established connection
#' # conn = tdConn(<username>, <password>)
#' # tdSpool(conn=conn)
#'
#' ## Uses same connection, but allows code to find globally
#' # tdSpool()
#'
#' @export
tdSpool = function(user="user", ...) {

	## Connection ##
	conn = tdCheckConn(list(...))

	query = gettextf(
			"select
				min(peakspool) MinSpool,
				avg(peakspool) MeanSpool,
				max(peakspool) MaxSpool,
				100*max(currentspool)/max(coalesce(maxprofilespool, maxspool)) as PercentInUse
				from dbc.DiskSpace
				where DatabaseName = %s;", user)
	tableInfo = td(query, conn=conn)

	## Connection ##
	if (	attr(conn, "tmpConnection")) DBI::dbDisconnect(conn)

	return(tableInfo)
}