Indexes are optional structures associated with tables used to speed query execution and/or guarantee uniqueness. Create an index if there are frequent retrieval of fewer than 10-15% of the rows in a large table and columns are referenced frequently in the WHERE clause. Implied tradeoff is query speed vs. update speed. Oracle automatically update indexes. Concatenated index max. is 16 columns.
How can variables be passed to a SQL routine?
What SQLPlus command is used to format output from a select?
What special Oracle feature allows you to specify how the cost based system treats a SQL statement?
ou want to group the following set of select returns, what can you group on? Max(sum_of_cost), min(sum_of_cost), count(item_no), item_no?
What is tkprof and how is it used?
What is explain plan and how is it used?
What is the default ordering of an ORDER BY clause in a SELECT statement?
You are joining a local and a remote table, the network manager complains about the traffic involved, how can you reduce the network traffic?
You want to determine the location of identical rows in a table before attempting to place a unique index on the table, how can this be done?
How do you prevent Oracle from giving you informational messages during and after a SQL statement execution?
rendc.org
Whether it is technological solutions or user-oriented innovations, We have put together for you the best sources of HR Interview Questions and Answers, Tech Ideas, and Programming Tutorials."
Get all the latest information on rendc.org
© 2022 | All rights reserved.
RENDC
welcome to www.rendc.org
