dbSendQuery using ROracle hangs while retrieving data

user9048328

Hi All,

I am facing issue with ROracle on Linux 7.X while fetching data from Oracle 12c Database (different box) using 18c client. While fetching data from R - R version 3.5.0 (2018-04-23) -- "Joy in Playing" using ROracle 1.3.1 and DBI 1.1.0 R package, process gets stuck and never comes out.

Psuedo code:

setwd("/srv/shiny-server/SimulationEngine_SIT/STDJD")

source("password_encryption.R")

library(ROracle)

library(DBI)

con <- dbConnect(drv=dbDriver("Oracle"),username=get_user(),password=get_decrypted_pass(),dbname=connect_string(),prefetch = FALSE)

S <- paste("select code, yearval, freq_code, freq_num, dataval from data_sim")

res <- dbSendQuery(con,S)

data <- fetch(res,n=-1)

When the last line is executed, process hangs and R console is not returned. Not sure where the problem lies , but i have never faced this issue earlier. Please help where am i going wrong here.

Sherry Lamonica-Oracle

How many rows are contained in the resulting table?  Does the hang still occur if you change n=-1 (fetch all records) to n=10 (fetch only the first 10 records)?

Sherry

user9048328

Hi Sherry,

Thanks for your reply. The resulting table contains 10838 records. Snapshot attached. Yes its still hangs when n is set to 1 or 10 and prefetch =  FALSE.

When I try setting prefetch = TRUE, n=1 and 200 works but hangs when n = 2000. Screenshot attached.

Sherry Lamonica-Oracle

I've tried to reproduce the problem but haven't been successful. Is it possible for you to send me a dummy data set that demonstrates the hang?

Thanks,
Sherry