What is the reason of high CPU cost but low IO cost?
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<p>I am running a query on a table which only has 283 records. The query is going for Full table scan as no indexed column value is passed in predicate. </p>

<p>Cost is only 12 , but CPU cost is very high - 4,75,189.</p>

<p>What is the reason for high CPU cost even though the table has very less no of records?</p>

<p>What is the difference between Cost &amp; CPU Cost?</p>

<p>PL SQL developer is used as an IDE.</p>

<p>Query -:</p>

<pre><code>SELECT     qmh_client, qmh_ip_timestamp, qmh_plant, qmh_key_tsklst_grp,
           qmh_grp_cntr, qmh_valid_dt, qmh_tdc_desc, qmh_cert_std,
           qmh_tsklst_usage, qmh_statu, qmh_lot_size_from, qmh_lot_size_to,
           qmh_tl_usage_uom, qmh_ctyp, qmh_cp_no, qmh_cp_version, qmh_tdform,
           qmh_ref_tdc, qmh_licn_no, qmh_guege_len, qmh_ip_activity,
           qmh_cp_activity, qmh_ip_sts_code, qmh_cp_sts_code, qmh_ltext_act,
           qmh_ltxt_sts_code, qph_ip_id, qmh_ip_mess, qmh_cp_id, qmh_cp_mess,
           qmh_rfd, qmh_smtp_addr, qmh_crt_time, qmh_crt_date, qmh_crt_by,
           qmh_ip_upd_time, qmh_ip_upd_date, qmh_ip_upd_by, qmh_cp_upd_time,
           qmh_upd_date, qmh_cp_upd_by, qmh_clas_sts_code, qmh_clas_id,
           qmh_clas_mess, qmh_clas_upd_time, qmh_clas_upd_date,
           qmh_clas_upd_by, qmh_prd_ind, qmh_tdc_type, qmh_pi_status
      FROM ipdmdm.t_qm_insp_hdr
     WHERE qmh_pi_status = 'N'
FOR UPDATE
</code></pre>