internal class Program
    {
        private static void Main()
        {
            var stopwatch = Stopwatch.StartNew();

          //  DateTime dt = new DateTime();
            try
            {
                const string oradb = "Data Source = 192.168.137.70/xe; " +
                                     "User id = useridb; Password = user1234";
#pragma warning disable 618
               var con = new OracleConnection(oradb);
#pragma warning restore 618
                con.Open();


#pragma warning disable 618
                var cmd = new OracleCommand {Connection = con};
#pragma warning restore 618



                for (var i = 0; i < 1000; i++)
                {
                    cmd.CommandText = "Insert into test (datetime) values (sysdate)";
                    //cmd.CommandText = "Select max(datetime) from test";
                    var dr = cmd.ExecuteReader();
                    dr.Read();

                   // dt = Convert.ToDateTime(dr.GetValue(0));
                    dr.Close();
                   // Thread.Sleep(50);
                }



                stopwatch.Stop();
                var averageTime = new TimeSpan(stopwatch.ElapsedMilliseconds / 1000);
                Console.WriteLine("Запись успешна {0},  {1}", averageTime, dt);
            }
            catch (Exception e)
            {
                Console.WriteLine("Error{0}", e.Message);
            }
            Console.ReadKey();
        }
    }

EXPLAIN PLAN FOR INSERT INTO TABLE values(10)

select name, value from v$parameter where name in ('timed_statistics','user_dump_dest');

select s.username, s.status, s.sid, s.serial#, sql_trace, s.program, p.spid
from v$session s join v$process p on s.paddr = p.addr
where s.username = 'SH1';

USERNAME      STATUS          SID    SERIAL# SQL_TRAC PROGRAM                        SPID
------------- -------- ---------- ---------- -------- ------------------------------ ------
SH1           ACTIVE          139         41 DISABLED SQL Developer                  26596
SH1           INACTIVE         15         92 DISABLED sqlplus@mpsrv (TNS V1-V3)      25930

exec sys.dbms_monitor.session_trace_enable(session_id=>139, serial_num=>41, waits=>true, binds=>false);
exec sys.dbms_monitor.session_trace_enable(session_id=>15,  serial_num=>92, waits=>true, binds=>false);

insert into tab1 (time) values (sysdate);
commit;

exec sys.dbms_monitor.session_trace_disable(session_id=>139, serial_num=>41);
exec sys.dbms_monitor.session_trace_disable(session_id=>15,  serial_num=>92);

$ ls -1t *26596.trc *25930.trc
myoradb_ora_25930.trc
myoradb_ora_25507.trc

tkprof myoradb_ora_25930.trc sqlp_25930.prf explain=sh1/sh1
tkprof myoradb_ora_26596.trc sqld_26596.prf explain=sh1/sh1

********************************************************************************
count    = number of times OCI procedure was executed
cpu      = cpu time in seconds executing
elapsed  = elapsed time in seconds executing
disk     = number of physical reads of buffers from disk
query    = number of buffers gotten for consistent read
current  = number of buffers gotten in current mode (usually for update)
rows     = number of rows processed by the fetch or execute call
********************************************************************************
SQL ID: f281fbsngrwq0
Plan Hash: 0
insert into tab1 (time)
values
 (sysdate)


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      0.00       0.00          0          0          0           0
Execute      1      0.00       0.00          0          1          5           1
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        2      0.00       0.00          0          1          5           1

Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 151  (SH1)

Rows     Row Source Operation
-------  ---------------------------------------------------
      0  LOAD TABLE CONVENTIONAL  (cr=1 pr=0 pw=0 time=0 us)


Rows     Execution Plan
-------  ---------------------------------------------------
      0  INSERT STATEMENT   MODE: ALL_ROWS
      0   LOAD TABLE CONVENTIONAL OF 'TAB1'


Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  SQL*Net message to client                       1        0.00          0.00
  SQL*Net message from client                     1        0.00          0.00
********************************************************************************

********************************************************************************
SQL ID: gck3089qg8n7x
Plan Hash: 0
insert into tab1 (time)
values
 (sysdate)

...
Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  Disk file operations I/O                        1        0.00          0.00
  log file sync                                   1        0.01          0.01
  SQL*Net message to client                       1        0.00          0.00
  SQL*Net message from client                     1        4.07          4.07