????????Batch??????????????????????????????????I/O?????????????????????????????????????????畏??????????????????????????CPU??????
????In List
????????????????????????????????????????????ID????????????些ID??????????????????????????????????????
????????????????????ID??????????????????????
????for: var in ids[] do begin
????SELECT * FROM table_name WHERE id=:var;
????end;
????????????????????????????????????????????????????????????????????????????????ID InList??????????????????谓??????????畏?????????????????
????SELECT * FROM table_name
????WHERE id IN ids[];
???????娲�????
????Inceptor???娲�??????????????娲�?????????????????????娲�????????SQL?????????????????????椤�??????????????????????????????????????????????????娲�?????械??????????????????????????????????????????????校??????????????娲�????????校????????SQL???????????
??????????????娲�?????????????????????
??????????????????????效???
?????????缃�???写??????????SQL??????????璨�???些???????????????????????????????????效???
????4. ??????????????
????CPU????SQL?谢????????????????????????CPU???????????????些???????????????????????纾�???卸?????????????????????????????????????????????????????CPU????????????????????????????????????????屑??????????????????????????????????????????????????????喂婊�????????????????
????????????SQL?械???????????Inceptor????????????????(??????????)?薪???????????????????CPU???????????????????????????琛�??LIKE????????????????CPU??????????????????????????????????????????????????????????????????寰�????In-List???LIKE????In-List?邪???LIKE???锌?????????睢�
????????3??????????????????
????SELECT * FROM table_name
????WHERE column_name LIKE ‘%abc%’;
???????????????????????????‘cabc’??‘abce’??‘cabe’???????????????????????????
????SELECT * FROM table_name
????WHERE column_name IN (‘cabc’?? ‘abce’?? ‘cabe’);
????????4?????In-List??????????SELECT??????????????????屑?小?????In?斜????????????????????????????????屑?????
????SELECT * FROM table_name
????WHERE column_name IN (
????SELECT col_name FROM tbl WHERE gender = ‘f’
????);
????????????????????Hadoop???谐????SQL????路???????????路?????????????????????????????????????些?路??????????????????SQL??????????些???????
?????????????????些????路?????贸????
????1???????????慰?????渭??????????;
????2??????SELECT?????????????渭??????????;
????3????????婕�????????????????????????????????????????????????;
????4????????????????????????????CPU????
????5???????????????????????????妫�???????????SQL??????Hadoop?????懈????????????