tag:blogger.com,1999:blog-34560741.post8710498230349923347..comments2023-11-02T12:22:23.089+03:00Comments on The Momen Blog: OOW-2012: Oracle 12c New FeaturesAsif Momenhttp://www.blogger.com/profile/08802175768050555784noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-34560741.post-6985136138557690892012-10-09T12:38:01.137+03:002012-10-09T12:38:01.137+03:00Hi Asif,
Adding Columns with a Default Value can ...Hi Asif,<br /><br />Adding Columns with a Default Value can be a "metadata only defualts" operation in 11g yet.<br /><br />http://www.oracle.com/technetwork/articles/sql/11g-schemamanagement-089869.html<br /><br />So, maybe they improved, in 12c, when this can be done.<br /><br />JoaquinJoaquin Gonzalezhttps://www.blogger.com/profile/12638256027643700661noreply@blogger.comtag:blogger.com,1999:blog-34560741.post-27412222896954114072012-10-08T12:45:31.818+03:002012-10-08T12:45:31.818+03:00Hi Iggy,
Here are the answers:
A-1:
I am trying...Hi Iggy,<br /><br />Here are the answers:<br /><br />A-1:<br /><br />I am trying to recollect my thoughts on this. Give me sometime to dig more details for this. <br /><br />A-2:<br />Typically when you add a new column with a default value to an existing table, Oracle visits each and every record and adds the new column with the default value. This operation is time & resource consuming when performed on a huge table. Starting 12c, this operation will be a "metadata only defaults" operation. Meaning, the alter statement will be non-resource intensive and completes very fast. Only the metadata of the column is updated to the default-value but not each and every row.<br /><br />AsifAsif Momenhttps://www.blogger.com/profile/08802175768050555784noreply@blogger.comtag:blogger.com,1999:blog-34560741.post-90446199729361562832012-10-07T14:40:53.467+03:002012-10-07T14:40:53.467+03:00Hi, Asif,
RE: "Default on null: A default va...Hi, Asif,<br /><br />RE: "Default on null: A default value is inserted into the column When it's null."<br /><br />How is this different from the "DEFAULT expr NOT NULL" clause of CREATE TABLE and ALTER TABLE?<br /><br />RE: "Improved defaults - metadata only defaults: Now add new default columns to a table on the fly. 12c does that for you."<br /><br />How is this different from the ADD clause of ALTER TABLE?<br /><br />IggyIggy Fernandezhttps://www.blogger.com/profile/02051194430083225321noreply@blogger.com