Quickest way to count table'srows

Question

Hi,
Can someone tell me the quickest wayo the count the number of rows in a table. I have large tables (many many millions of rows) and would like to obtain the row count as quickly as possible as i will be monitoring the size via OCI;
Cheers,
Warren

Answer 1

Donald
Can you prove that SELECT COUNT('X') FROM ..
is faster than SELECT COUNT(*) FROM ...
The suggestion for keeping the table analyzed then select NUM_ROWS from all_tables is good, Except that for an OLTP application, this would not be very practical.
If possible what can be done is
Create Table MY_TAB_COUNTS (NUM_ROWS NUMBER);
Insert into MY_TAB_COUNTS (select count(*) from THE_TABLE);
COMMIT;
Create or Replace Trigger T_AID_COUNTS
AFTER insert or delete on THE_TABLE
FOR EACH ROW
declare
begin
  if INSERTING then
     update MY_TAB_COUNTS Set Num_Rows = (Num_Rows + 1);
  else
     update MY_TAB_COUNTS Set Num_Rows = (Num_Rows - 1);
  end if;
end;
/Then, when the row counts is needed:
Select Num_Rows from MY_TAB_COUNTS;