6. What SQLPlus command is used to format output from a select?
Level: low Expected answer: This is best done with the COLUMN command.
View Article7. You 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 Level: Intermediate Expected answer: The only column that can be grouped on is the “item_no” column, the rest have aggregate functions...
View Article8. What special Oracle feature allows you to specify how the cost based...
Level: Intermediate to high Expected answer: The COST based system allows the use of HINTs to control the optimizer path selection. If they can give some example hints such as FIRST ROWS, ALL ROWS,...
View Article9. You want to determine the location of identical rows in a table before...
Level: High Expected answer: Oracle tables always have one guaranteed unique column, the rowid column. If you use a min/max function against your rowid and then select against the proposed primary key...
View Article10. What is a Cartesian product?
Level: Low Expected answer: A Cartesian product is the result of an unrestricted join of two or more tables. The result set of a three table Cartesian product will have x * y * z number of rows where...
View Article11. You are joining a local and a remote table, the network manager complains...
Level: High Expected answer: Push the processing of the remote data to the remote instance by using a view to pre-select the information for the join. This will result in only the data required for the...
View Article13. What is tkprof and how is it used?
Level: Intermediate to high Expected answer: The tkprof tool is a tuning tool used to determine cpu and execution times for SQL statements. You use it by first setting timed_statistics to true in the...
View Article14. What is explain plan and how is it used?
Level: Intermediate to high Expected answer: The EXPLAIN PLAN command is a tool to tune SQL statements. To use it you must have an explain_table generated in the user you are running the explain plan...
View Article15. How do you set the number of lines on a page of output? The width?
Level: Low Expected answer: The SET command in SQLPLUS is used to control the number of lines generated per page and the width of those lines, for example SET PAGESIZE 60 LINESIZE 80 will generate...
View ArticleWhat is an Object server?
With an object server, the Client/Server application is written as a set of communicating objects. Client object communicate with server objects using an Object Request Broker (ORB). The client invokes...
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