{"id":635,"date":"2008-10-03T12:09:20","date_gmt":"2008-10-03T11:09:20","guid":{"rendered":"http:\/\/soci.hu\/blog\/?p=635"},"modified":"2008-10-03T12:09:20","modified_gmt":"2008-10-03T11:09:20","slug":"guid-os-clustered-index-teljesitmeny","status":"publish","type":"post","link":"https:\/\/soci.hu\/blog\/index.php\/2008\/10\/03\/guid-os-clustered-index-teljesitmeny\/","title":{"rendered":"GUID-os clustered index teljes\u00edtm\u00e9ny"},"content":{"rendered":"<p>Sokan nem identity-s int-et hanem uniqueidentifiert haszn\u00e1lnak pk-k\u00e9nt olyan t\u00e1bl\u00e1kban, amelyet t\u00f6bb helyen m\u00f3dos\u00edtanak, pl. replik\u00e1ci\u00f3s fel\u00e1ll\u00e1sban. Nagyon helyesen.<br \/>\nA gond csak az, hogy a NEWID()-val gener\u00e1lt \u00e9rt\u00e9kek t\u00e9nyleg nagyon v\u00e9letlenszer\u0171 \u00e9rt\u00e9kek (\u00e9s a k\u00f6zhiedelemmel ellent\u00e9tben <em>nincs<\/em> benne a MAC address, mint r\u00e9gen). Ha a gener\u00e1lt \u00e9rt\u00e9ket egy clustered indexes (leggyakrabban primary key-es) oszlopban haszn\u00e1ljuk, akkor ez egym\u00e1s ut\u00e1n k\u00f6vetkez\u0151 besz\u00far\u00e1sok v\u00e9letlenszer\u0171 helyre ker\u00fclnek az adatb\u00e1zis f\u00e1jlban (ez \u00edgy pongyola, de nem akarom t\u00falr\u00e9szletezni), \u00e9s sz\u00e9tt\u00f6redezik a t\u00e1bla ezer darabra, r\u00e1ad\u00e1sul a lapok nem lesznek j\u00f3l kit\u00f6ltve, \u00e9s m\u00e9gis sok page split lesz. Sz\u00f3val g\u00e1z lesz az insert teljes\u00edtm\u00e9nye. Ezen seg\u00edthet a NEWSEQUENTIALID f\u00fcggv\u00e9ny, ennek teljes\u00edtm\u00e9ny\u00e9t \u00e9s fragment\u00e1l\u00e1si hat\u00e1s\u00e1t vizsg\u00e1lja <a href=\"http:\/\/www.fotia.co.uk\/fotia\/DY.19.NewSequentialId.aspx\">ez a cikk<\/a>.<br \/>\nAkinek ilyen jelleg\u0171 az adatb\u00e1zisa felt\u00e9tlen olvassa el a cikket. Sz\u00e1zszoros fragment\u00e1ci\u00f3 eset\u00e9n csak meg\u00e9ri elgondolkodni, nem?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Sokan nem identity-s int-et hanem uniqueidentifiert haszn\u00e1lnak pk-k\u00e9nt olyan t\u00e1bl\u00e1kban, amelyet t\u00f6bb helyen m\u00f3dos\u00edtanak, pl. replik\u00e1ci\u00f3s fel\u00e1ll\u00e1sban. Nagyon helyesen. A gond csak&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,4,21,58],"tags":[],"class_list":["post-635","post","type-post","status-publish","format-standard","hentry","category-adatbazisok","category-szakmai-elet","category-sql-server-2005","category-sql-server-2008"],"_links":{"self":[{"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/635","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=635"}],"version-history":[{"count":1,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/635\/revisions"}],"predecessor-version":[{"id":636,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/635\/revisions\/636"}],"wp:attachment":[{"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=635"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=635"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/soci.hu\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}