Two Sigma Database Administrator interview questions

Write the sql for deleting duplicate rows from a table without using temporary space.

You have 10 tables that are truncated at the end of every day. They all grow simultaneously throughout the day. How do you avoid fragmentation problems?

Assume a table, task, with the following columns: § task_id (int, Not NULL) § task_description (text, Not NULL) § parent_task_id (int, NULL) Write a stored procedure and program (in any language of your choosing) to produce a text based hierarchical tree of the tasks rooted at a given task, using tabs to show the hierarchy. For example, if these rows exist in the task table: task_idtask_descriptionparent_task_id 1Eat LunchNULL 2Choose restaurant1 3Order food1 4Call restaurant3 5Have staff meetingNULL 6Send agenda5 And your program in invoked as follows: tasktree –t 1 It will produce this output: Eat Lunch Choose restaurant Order food Call restaurant

Provide a code sample from a program you wrote to automate a database related task.