Java Exception error while reading large data in R from DB using RJDBC.

I didn't have the same exception yet, but please make sure you have a stable connection (avoid wlan).
I personally ran out of memory very often and had to make several queries, combining the results in R instead.

This is probably not the best thing to do, but worked for me to fetch large amounts of data, though it takes a while:
	
res<-dbSendQuery(conn,query)
result<-list()
i=1
result[[i]]<-fetch(res,n=100000)
while(nrow(chunk <- fetch(res, n = 100000))>0){
	i<-i+1
	result[[i]]<-chunk
}
allResults<-do.call(rbind,result)

On 30.10.2012, at 12:32, aajit75 wrote:

Dear List,

Java Exception error while reading large data in R from DB using RJDBC.
I am trying to read large data from DB table(Vectorwise), using RJDBC
connection.
I have tested the connection with small size data and was able to fetch DB
tables using same connection(conn as in my code).  

Please suggest where  am i going wrong or alternate option to solve such
issues  while reading large DB table.

drv <- JDBC(paste(db_driver,  sep = ""),
         paste(db_jar_file,  sep = ""),
         identifier.quote="`")

conn <<- dbConnect(drv, paste(db_server,  sep = ""),
					paste(db_server_lgn,  sep = ""), 
					paste(db_server_pwd,  sep = ""))
s <- sprintf("select * from  cypress_modeldev_account_info")
temp <- dbGetQuery(conn, s) 
Error in .jcheck() : 
Java Exception <no description because toString() failed>.jcall(rp, "I",
"fetch", stride)<S4 object of class "jobjRef">




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