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Oracle Tips by Burleson |
Aggregation
Denormalization
In Oracle data warehouses, a table might have
millions of rows, and SQL queries might take hours to run. To solve
this problem, Oracle has a tool called a materialized view
to pre-summarize data and pre-join table together.
When you pre-summarize data with materialized
views, you don’t need to change your SQL! Oracle has a super-cool
feature called query re-write where Oracle will automatically know
when your SQL can use a pre-summarized result.
So, I have my data, and I want to start building
my database. How can I visualize my data and go through the
normalization process with out constantly recreating the database? For
this, you want to use the Entity Relation Diagram
.
The above book excerpt is from:
Easy Oracle
SQL
Get Started
Fast writing SQL Reports with SQL*Plus
ISBN 0-9727513-7-8
John Garmany
http://www.rampant-books.com/book_2005_1_easy_sql.htm |
