```language
#include <oci.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

OCIError *errhp;
OCIEnv *envhp;
OCICPool *poolhp;
OraText *poolName;
sb4 poolNameLen;

CONST OraText *database = (OraText *)"192.168.0.111";
CONST OraText *username = (OraText *)"SYSDBA";
CONST OraText *password = (OraText *)"SYSDBA";

// #define USE_SESSION_POOL

/* Local functions */
void checkerr(OCIError *errhp, sword status);
void initBySession();
void queryRowsBySession();

int main()
{
    initBySession();

    checkerr(errhp, OCISessionPoolDestroy(poolhp, errhp, OCI_DEFAULT));
    checkerr(errhp, OCIHandleFree((dvoid *)poolhp, OCI_HTYPE_CPOOL));
    checkerr(errhp, OCIHandleFree((dvoid *)errhp, OCI_HTYPE_ERROR));

    return 0;
}

void initBySession()
{
    sword lstat;
    int timeout = 1;

    OCIEnvCreate(&envhp, OCI_THREADED, (dvoid *)0, NULL, NULL, NULL, 0, (dvoid *)0);
    OCIHandleAlloc((dvoid *)envhp, (dvoid **)&errhp, OCI_HTYPE_ERROR, (size_t)0, (dvoid **)0);
    OCIHandleAlloc((dvoid *)envhp, (dvoid **)&poolhp, OCI_HTYPE_SPOOL, (size_t)0, (dvoid **)0);

    printf("envhp: %p, errhp: %p, poolhp: %p\n", &envhp, &errhp, &poolhp);

    checkerr(errhp, OCIAttrSet((dvoid *)poolhp, (ub4)OCI_HTYPE_SPOOL, (dvoid *)&timeout, (ub4)0, OCI_ATTR_SPOOL_TIMEOUT, errhp));

    /* Create the session pool */
    if (lstat = OCISessionPoolCreate(envhp, errhp, poolhp, (OraText **)&poolName, (ub4 *)&poolNameLen,
                                     database, (ub4)strlen((const signed char *)database),
                                     0, 1, 1,
                                     (OraText *)username, (ub4)strlen((const signed char *)username),
                                     (OraText *)password, (ub4)strlen((const signed char *)password),
                                     OCI_DEFAULT))
    {
        printf("Session Pool Created Error\n");
        checkerr(errhp, lstat);
        return;
    }

    printf("Session Pool Created OK\n");
}

void checkerr(OCIError *errhp, sword status)
{
    text errbuf[512];
    sb4 errcode = 0;

    switch (status)
    {
    case OCI_SUCCESS:
        break;
    case OCI_SUCCESS_WITH_INFO:
        (void)printf("Error - OCI_SUCCESS_WITH_INFO\n");
        break;
    case OCI_NEED_DATA:
        (void)printf("Error - OCI_NEED_DATA\n");
        break;
    case OCI_NO_DATA:
        (void)printf("Error - OCI_NODATA\n");
        break;
    case OCI_ERROR:
        (void)OCIErrorGet((dvoid *)errhp, (ub4)1, (text *)NULL, &errcode,
                          errbuf, (ub4)sizeof(errbuf), OCI_HTYPE_ERROR);
        (void)printf("Error - %d, %.*s\n", errcode, 512, errbuf);
        break;
    case OCI_INVALID_HANDLE:
        (void)printf("Error - OCI_INVALID_HANDLE\n");
        break;
    case OCI_STILL_EXECUTING:
        (void)printf("Error - OCI_STILL_EXECUTE\n");
        break;
    case OCI_CONTINUE:
        (void)printf("Error - OCI_CONTINUE\n");
        break;
    default:
        (void)printf("Error - unknown error, status: %d\n", status);
        break;
    }
}