Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

SQL Server 2008ÐÐÊý¾ÝºÍÒ³Êý¾ÝѹËõ½âÃÜ

SQL ServerµÄÐÔÄÜÖ÷Ҫȡ¾öÓÚ´ÅÅÌI/OЧÂÊ£¬Ìá¸ßI/OЧÂÊijÖÖ³ÌÐòÉϾÍÒâζ×ÅÌá¸ßÐÔÄÜ¡£SQL Server 2008ÌṩÁËÊý¾ÝѹËõ¹¦ÄÜÀ´Ìá¸ß´ÅÅÌI/O¡£
Êý¾ÝѹËõÒâζ׿õСÊý¾ÝµÄÓдÅÅÌÕ¼ÓÃÁ¿£¬ËùÒÔÊý¾ÝѹËõ¿ÉÒÔÓÃÔÚ±í£¬¾Û¼¯Ë÷Òý£¬·Ç¾Û¼¯Ë÷Òý£¬ÊÓͼË÷Òý»òÊÇ·ÖÇø±í£¬·ÖÇøË÷ÒýÉÏ¡£
Êý¾ÝѹËõ¿ÉÒÔÔÚÁ½¸ö¼¶±ðÉÏʵÏÖ£ºÐм¶±ðºÍÒ³¼¶±ð¡£Ò³¼¶±ðѹËõ°üÀ¨Ðм¶±ðѹËõ¡£±íºÍË÷ÒýÔÚ´´½¨µÄͬʱ¾Í¿ÉÒÔѹËõ£¬Ò²¿ÉÒÔʹÓÃAlter Table Rebuild With »òÊÇ Alter Index Rebuild WithÓ﷨ѹËõÒÑ´æÔÚ±í»òÊÇË÷Òý¡£µ±¶Ñ(Heap)ÉϵÄѹËõ״̬¸Ä±äʱ£¬ËùÓеķǾۼ¯Ë÷ÒýÒ²»áÖØ½¨¡£
ÏÂÃæÈÃÎÒÃÇ¿´¿´Ñ¹Ëõ¹ý³Ìµ½µ×¶¼×öÁËЩʲô¡£
ÐÐѹËõ£º
1.¼õÉÙÔªÊý¾ÝÍ·¼Ç¼Êý¾Ý¡£
2.ËùÓеÄÊýÖµÀàÐÍ(integer,decimal,float)»ò»ùÓÚÊýÖµÀàÐ͵ÄÀàÐͶ¼»á±»Ñ¹Ëõ(datetime,money)¡£±ÈÈ磬100±»´æÔÚÒ»¸öintÐÍ×Ö¶ÎÖУ¬Õ¼4룬µ«ÊÇ´Ó0~255Ö»ÐèÒª1λ£¬Ñ¹Ëõºó£¬¾Í½ÚÊ¡ÁË3byte¿Õ¼ä¡£
3.CharºÍNChar¶¼±»´æ·ÅÓڿɱ䳤¶ÈµÄÀàÐÍÖС£Ô­ÒòͬÉÏ¡£±ÈÈ磬CSDN±»´æÔÚChar(10)ÖУ¬µ«ÊÇËüÖ»ÐèÒªChar(4)¿Õ¼ä£¬ËùÒÔѹËõºó¾ÍÊÍ·ÅÁËChar(6)¸ö¿Õ¼ä¡£
4.ËùÓÐÀàÐ͵ÄNULLºÍ0¶¼²»Õ¼×Ö½ÚÁË¡£
ҳѹËõ£º
1.½øÐÐÐÐѹËõ¡£
2.ǰ±êѹËõ£ºÃ¿Ò»Ò³ÖеÄËùÓÐÁУ¬ÔÚÐбêÍ·ÏÂÃæ£¬Ã¿Ðж¼´æ´¢×ÅÒ»¸öÐж¨ÒåÖµ£¬Ñ¹Ëõºó£¬ËùÓÐÐе͍ÒåÖµ¶¼±»Ìæ»»³ÉÐÐÍ·ÖµµÄÒýÓá£
3.×ÖµäѹËõ£º×ÖµäѹËõºÍǰ±êѹËõÀàËÆ¡£Ç°±êѹËõÖУ¬Ò»¸öÓëÆäËûÆÕֵͨ²»Í¬µÄÖµ±»¶¨Ò嵽ÿһÁÐÉÏ¡£µ«ÊÇ×ÖµäѹËõÖУ¬Ã¿Ò»Ò³ÖÐËùÓÐÁÐµÄÆÕֵͨ±»´æÔÚÏÂÒ»ÐеÄÐÐÍ·Ç°Ãæ¡£È»ºó£¬ÕâЩֵ±»Ìæ»»³ÉÐÂÐеÄÒýÓÃÖµ¡£
ÏÂÃæÎÒÃÇÀ´¿´Ò»¸öÀý×Ó:
USE tempdb
GO
CREATE TABLE TestCompression (col1 INT, col2 CHAR(50))
GO
INSERT INTO TestCompression VALUES (10, 'compression testing')
GO 5000
-- Original
EXEC sp_spaceused TestCompression
GO
-- DATA_COMPRESSION = ROW
ALTER TABLE TestCompression
REBUILD WITH (DATA_COMPRESSION = ROW);
GO
EXEC sp_spaceused TestCompression
GO
-- DATA_COMPRESSION = PAGE
ALTER TABLE TestCompression
REBUILD WITH (DATA_COMPRESSION = PAGE);
GO
EXEC sp_spaceused TestCompression
GO
-- DATA_COMPRESSION = NONE
ALTER TABLE TestCompression
REBUILD WITH (DATA_COMPRESSION = NONE);
GO
EXEC sp_spaceused TestCompression
GO


Ïà¹ØÎĵµ£º

Ò»¸ö×Ö¶ÎÆ¥ÅäµÄsqlÓï¾äÊéд

Õ⼸Ì츺ÔðÒ»¸ö¼Ò½ÌÃÅ»§ÍøÕ¾µÄ¿ª·¢£¬»ùÓÚcakephp¿ò¼Ü¡£ÔÚÅàѵ»ú¹¹±í£¨schools£©ÖдæÔÚÒ»¸ö×Ö¶ÎsubjectÓÃÀ´´æ´¢ÁíÒ»¸öÊý¾Ý±í
£¨subjects£©ÖмǼµÄidÖµ£¬ÇÒ´æ´¢ÐÎʽΪ£º'1,2,3,4,5'¡£µ«ÊÇÔÚÓ¦Óø߼¶ËÑË÷¹ýÂËÊ±Ò³ÃæselectÑ¡ÏîoptionµÄ´«ÖµÎª
subjectsµÄidÖµ£¬ÐèÒªÅжϲéѯ±íschoolsÖÐsubject×ֶδæÔÚ´Ëid£¬¼´²éѯÏÔʾ´Ë¼Ç¼ ......

SQLº¯Êý´óÈ«

¾ÛºÏº¯Êý
MAX(×Ö¶Î)      
Çóij×Ö¶ÎÖеÄ×î´óÖµ
MIN(×Ö¶Î)
    
Çóij×Ö¶ÎÖеÄ×îСֵ
AVG(×Ö¶Î)
     
Çóij×Ö¶ÎÖÐµÄÆ½¾ùÖµ
SUM(×Ö¶Î)
    
Çóij×Ö¶ÎÖеÄ×ܺÍ
COUNT(×Ö¶Î) 
ͳ¼ÆÄ³×ֶηǿռͼÊý
COUNT
......

SQL ServerÀïÃæµÄUËø

XËø¼´ÊÇÎÒÃdz£ËµµÄÅÅËüËø£¬UËøºÜÉÙ¼û£¬Ö»ÔÚ¸üÐÂʱ»á³öÏÖ¡£UËøÆäʵÊÇXËøµÄÒ»ÖÖ£¬µ±Êý¾Ý¸üÐÂʱ£¬UËøÊ×Ïȼӵ½Òª¸üеÄÊý¾ÝÉÏ(¼´Ê¹Ä¿±êÉÏÃæÓÐSËø£¬UËø»¹ÊÇ¿ÉÒÔ¼ÓÉÏ)£¬µÈÄ¿±ê¿ÉÒÔ±»¸üÐÂʱ£¬UËø¼´×ª±äΪXËø¡£ ÈçÐè×ªÔØ£¬Çë×¢Ã÷±¾ÎÄÔ­´´×ÔCSDN TJVictorרÀ¸£ºhttp://blog.csdn.net/tjvictor ......

SQL Server´æ´¢¹ý³Ì½éÉÜ


ÕªÒª£º±¾ÎĽéÉÜÁËSQL Server´æ´¢¹ý³ÌÏà¶ÔÓÚÆäËûµÄÊý¾Ý¿â·ÃÎÊ·½·¨µÄÓŵ㼰SQL Server´æ´¢¹ý³ÌµÄ·ÖÀàµÈ¡£
SQL Server´æ´¢¹ý³ÌÊÇÒ»¸ö±»ÃüÃûµÄ´æ´¢ÔÚ·þÎñÆ÷ÉϵÄTransacation-SqlÓï¾ä¼¯ºÏ,ÊÇ·â×°ÖØ¸´ÐÔ¹¤×÷µÄÒ»ÖÖ·½·¨,ËüÖ§³ÖÓû§ÉùÃ÷µÄ±äÁ¿¡¢Ìõ¼þÖ´ÐÐºÍÆäËûÇ¿´óµÄ±à³Ì¹¦ÄÜ¡£
SQL Server´æ´¢¹ý³ÌÏà¶ÔÓÚÆäËûµÄÊý¾Ý¿â·ÃÎÊ·½·¨Ó ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ