Oracle 11g Release 2

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WITH names AS (
     SELECT 'mytabname' tabname
     FROM dual
     UNION ALL
     SELECT 'mytabname1'
     FROM dual
     UNION ALL
     SELECT 'mytabname_'
     FROM dual
     UNION ALL
     SELECT 'mytabnameX'
     FROM dual
     UNION ALL
     SELECT '1mytabname'
     FROM dual
     UNION ALL
     SELECT '_mytabname'
     FROM dual
     UNION ALL
     SELECT 'Xmytabname'
     FROM dual
     UNION ALL
     SELECT '1mytabname_'
     FROM dual
     UNION ALL
     SELECT '1mytabnameX'
     FROM dual
     UNION ALL
     SELECT '_mytabname1'
     FROM dual
     UNION ALL
     SELECT 'Xmytabname1'
     FROM dual
     UNION ALL
     SELECT '_mytabnameX'
     FROM dual
     UNION ALL
     SELECT 'Xmytabname_'
     FROM dual
     UNION ALL
     SELECT '_mytabname_'
     FROM dual
     UNION ALL
     SELECT 'XmytabnameX'
     FROM dual
     UNION ALL
     SELECT '1mytabname1'
     FROM dual
     UNION ALL
     SELECT ' mytabname_'
     FROM dual
     UNION ALL
     SELECT '_mytabname '
     FROM dual
     UNION ALL
     SELECT ' mytabname '
     FROM dual
     UNION ALL
     SELECT ' mytabnameX'
     FROM dual
     UNION ALL
     SELECT 'Xmytabname '
     FROM dual
     UNION ALL
     SELECT ' mytabname1'
     FROM dual
     UNION ALL
     SELECT '1mytabname '
     FROM dual
     UNION ALL
     SELECT '.mytabname '
     FROM dual
     UNION ALL
     SELECT ' mytabname.'
     FROM dual
     UNION ALL
     SELECT '.mytabname.'
     FROM dual
     UNION ALL
     SELECT '*mytabname'
     FROM dual
     UNION ALL
     SELECT ' mytabname*'
     FROM dual
     UNION ALL
     SELECT '*mytabname*'
     FROM dual
     UNION ALL
     SELECT 'defmytabnameabc'
     FROM dual
) SELECT tabname,'start' || tabname || 'end'
  FROM names
  WHERE REGEXP_LIKE ( tabname,
                      '(\W|^)' || 'mytabname' || '(\W|$)', 'i' );

TABNAME	'START'\|\|TABNAME\|\|'END'
mytabname	startmytabnameend
mytabname	start mytabname end
.mytabname	start.mytabname end
mytabname.	start mytabname.end
.mytabname.	start.mytabname.end
*mytabname	start*mytabnameend
mytabname*	start mytabname*end
mytabname	startmytabnameend