rownum À» ÀÌ¿ëÇÏ¸é °¡´É ÇÕ´Ï´Ù.
emp Å×ÀÌºí µÎ°³¸¦ natural Á¶ÀÎÀ» ÇÏ¿© (a,b ¶ó°í ÇÔ) a ÀÇ rownumÀÌ
bÀÇ rownum º¸´Ù Å« ·¹ÄÚµåÀÇ sumÀ» ±¸ÇÏ´Â °Ì´Ï´Ù.
Äڵ带 ¿Ï¼ºÇÏ¸é ´ÙÀ½°ú °°ÀÌ µÇ°ÚÁö¿ä..
select a.empno, a.ename ename, a.sal sal, sum(b.sal)
from
(select /*+index (emp pk_emp)*/ rownum num,empno, ename, sal from emp) a,
(select /*+index (emp pk_emp)*/ rownum num,empno, ename, sal from emp) b
where a.num >= b.num
group by a.empno,a.ename,a.sal
order by a.empno
Âü°í·Î rownumÀº »ç¿ëÇϽǶ§ ÁÖÀÇ ÇÏ¼Å¾ß ÇÏ´Â °ÍÀº ¾Ë°í °è½ÃÁÒ?
Âü°í·Î inline view(from ÀÌÈÄÀÇ select ±¸¹®) ¿¡¼ rownum°ú order by ´Â °°ÀÌ »ç¿ëÇÏÁö ¸¶½Ê½Ã¿ä..
/*+index (emp pk_emp)*/ Àº ÈùÆ®Àý(ÀÏ¹Ý ÁÖ¼®ÀÌ ¾Æ´Ô) À̸ç empÅ×ÀÌºí¿¡¼ µ¥ÀÌÅ͸¦ ÃßÃâÇÒ¶§ pk_empÀÇ ¼ø¼·Î »ÌÀ¸¶ó´Â À̾߱â ÀÔ´Ï´Ù.
a.empno ´Â ¸¶Áö¸·À¸·Î µ¥ÀÌÅ͸¦ Á¤·ÄÇϱâ À§ÇØ ¾î¿¼ö ¾øÀÌ Ãâ·ÂÇÏ¿´½À´Ï´Ù.
±×·³ µµ¿òÀÌ µÇ¼Ì±â¸¦..
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