问题
Simple R script
library(RODBC)
odbChannel <- odbcConnect(dsn = "CTPRD03", uid = "BD_RPT_RO", pwd = "****")
df.test <- sqlQuery(channel = odbChannel, query = "select * from DUAL;")
df.test
close(odbChannel)
Produces the following error
shiny@narc07shiny1dev:~/software> Rscript ./RODBC_SIMPLE_TEST.r
Error in odbcQuery(channel, query, rows_at_time) :
'Calloc' could not allocate memory (18446744073709551616 of 22816 bytes)
Calls: sqlQuery -> odbcQuery -> .Call
Execution halted
Warning message:
closing unused RODBC handle 1
Tested odbc outside of R and was able to get results. I'm not sure where the problem is at this point. I'm thinking it is RODBC.
Already uninstalled RODBC and reinstalled the RODBC package and there were no errors during that process, but still have the same results.
Found one case out there with the same problem but there wasn't any resolution. What would be next steps in isolating the problem, any suggestions?
回答1:
I had a similar problem and fixed by adding rows_at_time = 1 to the connection.
odbChannel <- odbcConnect(dsn = "CTPRD03", uid = "BD_RPT_RO", pwd = "****", rows_at_time = 1)
I also found this blurb in the documentation:
https://cran.r-project.org/web/packages/RODBC/RODBC.pdf
Several errors which have been reported as bugs in RODBC 1.3-0 which were in fact ODBC driver errors that can be circumvented by setting rows_at_time = 1 (and the warning under that argument has always been there). The drivers involved have been third-party Oracle drivers and old SQL Server drivers.
回答2:
What type of database architecture are you connecting to? If it doesn't match the version of R you're using, the query won't run. For example, if you're using 64-bit R but you are trying to connect to a Microsoft Access 2007 or earlier database (which is 32-bit) you won't be able to run the query.
If you're using R Studio, go to the 'Tools' menu then 'Global Options' and you can change the version of R you're using to match that of the database.
来源：https://stackoverflow.com/questions/30581046/rodbc-cannot-allocate-memory