Prescreening Questions Plsql

[tommy]

  Bhayya ee questions ki answers telisthe chepara...prescreening questions for plsql dev position...

1) Describe your typical approach to trouble shooting (for example:  you aren’t getting the expected results returned in your query)?

 

2.       2) When you have several things going on at the same time, how do you determine priority and keep track of them all to make sure nothing falls through the cracks?

 

3.       3) Describe the most complex procedure written by someone else, that you have been assigned to debug?

 

4.       4) When and why should Views be used?

 

5.       5) In a procedure, how do you access data from another schema? 

 

6.       6) Give some examples of using ‘Explain plan’  in order to improve performance.

 

7.       7) What is the term “cascade constraints”  and how it is used?

 

8.       8) If there is an oracle query populating a reporting page,  and we only gave you the name of the java screen,  what steps would you take to troubleshoot a performance issue with that screen?

[Pournami1]

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[rondon9999]

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[tommy]

  Bhayya ee questions ki answers telisthe chepara...prescreening questions for plsql dev position...

1) Describe your typical approach to trouble shooting (for example:  you aren’t getting the expected results returned in your query)?

 

2.       2) When you have several things going on at the same time, how do you determine priority and keep track of them all to make sure nothing falls through the cracks?

 

3.       3) Describe the most complex procedure written by someone else, that you have been assigned to debug?

 

4.       4) When and why should Views be used?

 

5.       5) In a procedure, how do you access data from another schema? 

 

6.       6) Give some examples of using ‘Explain plan’  in order to improve performance.

 

7.       7) What is the term “cascade constraints”  and how it is used?

 

8.       8) If there is an oracle query populating a reporting page,  and we only gave you the name of the java screen,  what steps would you take to troubleshoot a performance issue with that screen?

 

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[tommy]

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[StuartBinny]

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[NewUser123]

    5) In a procedure, how do you access data from another schema? 

The access to select the table in the schema Schema2 is granted through a Role for you. You need to have direct grant in order to access the table in the schema Schema2 through a stored procedure

[NewUser123]

4) When and why should Views be used?

Several reasons: If you have complicated joins, it is sometimes best to have a view so that any access will always have the joins correct and the developers don;t have to remember all the tables they might need. Typically this might be for a finacial application where it would be extremely important that all financial reports are based on the same set of data.

If you have users you want to limit the records they can ever see, you can use a view, give them access only to the view not the underlying tables and then query the view

Crystal reports seems to prefer to use views to stored procs, so people who do a lot of report writing tend to use a lot of views

 

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A view provides several benefits.

1. Views can hide complexity

If you have a query that requires joining several tables, or has complex logic or calculations, you can code all that logic into a view, then select from the view just like you would a table.

2. Views can be used as a security mechanism

A view can select certain columns and/or rows from a table, and permissions set on the view instead of the underlying tables. This allows surfacing only the data that a user needs to see.

3. Views can simplify supporting legacy code

If you need to refactor a table that would break a lot of code, you can replace the table with a view of the same name. The view provides the exact same schema as the original table, while the actual schema has changed. This keeps the legacy code that references the table from breaking, allowing you to change the legacy code at your leisure.

 

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copied from stackoverflow.

[NewUser123]

   7) What is the term “cascade constraints”  and how it is used?

 

Deletes all Foreign keys that reference the table to be dropped, then drops the table

[ramu]

Bhayya ee questions ki answers telisthe chepara...prescreening questions for plsql dev position...
1) Describe your typical approach to trouble shooting (for example: you aren’t getting the expected results returned in your query)?
All tables we r referring should be available in accessible schema..join conditions ..any functional modification on columns being used in where clause.
2. 2) When you have several things going on at the same time, how do you determine priority and keep track of them all to make sure nothing falls through the cracks?
Based on user priorities n functionality of the application. ..tasks will be dealt with n version control will used to make sure no work is lost. Extensive unit testing is done to make sure there rn't any bugs.
3. 3) Describe the most complex procedure written by someone else, that you have been assigned to debug?
4. 4) When and why should Views be used?to mask original tables from original users. To reduce load from master tables n to avoid any locks from happening due to concurrent access from db n users.

5. 5) In a procedure, how do you access data from another schema? role based access. Refer to table with schemaname.tablename

6. 6) Give some examples of using ‘Explain plan’ in order to improve performance.

7. 7) What is the term “cascade constraints” and how it is used?

8. 8) If there is an oracle query populating a reporting page, and we only gave you the name of the java screen, what steps would you take to troubleshoot a performance issue with that screen? identify the query thts being called from UI via jsp page n java method thts getting executed behind the scene..(similar may not be perfect..cross check)

[afuser]

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[former]

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