RMySQL (version 0.9-3)

dbApply-methods: Apply R/S-Plus functions to remote groups of DBMS rows (experimental)

Description

Applies R/S-Plus functions to groups of remote DBMS rows without bringing an entire result set all at once. The result set is expected to be sorted by the grouping field.

References

See the Database Interface definition document DBI.pdf in the base directory of this package or http://stat.bell-labs.com/RS-DBI.

See Also

MySQL mysqlDBApply dbSendQuery fetch

Examples

## compute quanitiles for each network agent
con <- dbConnect(MySQL(), group="vitalAnalysis")
rs <- dbSendQuery(con, 
             "select Agent, ip_addr, DATA from pseudo_data order by Agent")
out <- dbApply(rs, INDEX = "Agent", 
        FUN = function(x, grp) quantile(x$DATA, names=FALSE))