Re: Sql*Loader, Bequeath and ulimit

ErikYkema <erik.ykema_at_gmail.com> wrote:
> We just experienced the following ulimit event in a production
> Sql*Loader run, and I am looking for your help in understanding why it
> is as we saw.
>
> Oracle EE 817_at_AIX5L.
> Ulimit for Oracle for fsize is unlimited, ulimit fsize for user that
> calls sqlldr is 2 GB. We insert (not direct path) and connect using
> beq (no @SID in connect string) and receive a message like:
> ORA-01115: IO error reading block from file 1 (block # 5970)
> ORA-01110: data file 1: '/db8/rstst/system.dbf'
> ORA-27092: skgfofi: size of file exceeds file size limit of the
> process
>
> It turns out that this datafile is around 2GB in size.
> I first thought that the instance had been started in a wrong way,
> using wrong (2GB) ulimit. A bounce of the instance with correct
> environment didn't solve it.
>
> We were able to insert the rows using Sql*Plus inserts manually (and
> to extend the dbf.)
>
> We found some references on the internet confirming the problem and
> the following suggested approaches:
> - either make sure the user that calls sqlldr has a ulimit at least
> equal to oracle
> - and/or make sure not to connect sqlldr using beq
>
> An operator assures us that he has set the ulimit fsize (hard and
> soft) for the calling user to 4 GB, and still was not able to complete
> the sqlldr run succesfully, on the same error.
>
> Now our assumption for explaining this is:
> When calling the sqlldr executable using beq, the oracle server side
> process that writes (and reads) the data file does not have exactly
> the same ulimit as the other instance oracle processes. It also seems
> not to have the calling user's ulimit. (If the operator's observation
> was correct.)
>
> Why would/could this process be different? What is exactly the nature
> of this process? Or is something else going on?
> Would this case also hold for imp and other Oracle Utilities?

I can confirm everything except for the operator's observations.

• When you use BEQ protocol, the server process is forked from the client process (as you can verify with ps). This is the same for all client utilities like sqlldr, imp, or impdp.
• A forked process will inherit the ulimit settings from the parent process, even if it is SETUID like oracle (I checked this with a small C program).

So when using sqlldr via BEQ protocol, the ulimits of the calling user should apply.

I would double check your operator's assumption; try and set ulimit -f to the desired value manually, check it with ulimit -a, then start the sqlldr process from the same shell and see what happens.

Yours,
Laurenz Albe

PS: This is the C program I used to check my claim:

#include <stdio.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/resource.h>

int main(int argc, char **argv) {
        struct rlimit64 rl;

        if (-1 == getrlimit64(RLIMIT_FSIZE, &rl)) {
                perror("getrlimit");
                return 1;
        }

        printf("Current file size limit: %lld bytes\n", rl.rlim_cur);
        return 0;