dbApply-methods {RPostgreSQL} | R Documentation |
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.
Methods
- res
a PostgreSQL result set (see
dbSendQuery
).- ...
any additional arguments to be passed to
FUN
.
References
See the Database Interface definition document
DBI.pdf
in the base directory of this package
or
https://cran.r-project.org/package=DBI.
See Also
PostgreSQL
postgresqlDBApply
dbSendQuery
fetch
Examples
## Not run:
## compute quanitiles for each network agent
con <- dbConnect(PostgreSQL(), user="user", password="passwd",dbname="dbname")
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))
## End(Not run)
[Package RPostgreSQL version 0.7-6 Index]