Here are few interview questions with answers found on the internet.

As I don't have time to format these questions to wiki I am just posting them hoping someone to format them. Explain the difference between a hot backup and a cold backup and the benefits associated with each.

oracle updating cursor loop-81

For passing in variables the numbers 1-8 can be used (&1, &2,...,&8) to pass the values after the command into the SQLPLUS session. What SQLPlus command is used to format output from a select This is best done with the COLUMN command. 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 The only column that can be grouped on is the "item_no" column, the rest have aggregate functions associated with them. What special Oracle feature allows you to specify how the cost based system treats a SQL statement The COST based system allows the use of HINTs to control the optimizer path selection.

To be prompted for a specific variable, place the ampersanded variable in the code itself: "select * from dba_tables where owner=&owner_name;" . ); spool off Essentially you are looking to see that they know to include a command (in this case DROP USER... If they can give some example hints such as FIRST ROWS, ALL ROWS, USING INDEX, STAR, even better. 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 Oracle tables always have one guaranteed unique column, the rowid column.

As objects grow they take chunks of additional storage that are composed of contiguous data blocks.

These groupings of contiguous data blocks are called extents.

If you do a comparison between pairs of readings based on some arbitrary time span, this is the instantaneous ratio for that time span. Another if you are on UNIX is to do a "ps -ef|grep oracle|wc -l?

Generally speaking an instantaneous reading gives more valuable data since it will tell you what your instance is doing for the time it was generated over. command, but this only works against a single instance installation. A user selects from a sequence and gets back two values, his select is: SELECT pk_seq.nextval FROM dual; What is the problem Somehow two values have been inserted into the dual table.

All the extents that an object takes when grouped together are considered the segment of the database object.

Both the truncate and delete command have the desired outcome of getting rid of all the rows in a table.

The difference between the two is that the truncate command is a DDL operation and just moves the high water mark and produces few rollback data.

The delete command, on the other hand, is a DML operation, which will produce rollback data and thus take longer to complete. When a user process fails, what background process cleans up after it? Describe the difference between a procedure, function and anonymous pl/sql block.

In Oracle 8 they will be able to be of the %ROWTYPE designation, or RECORD. It must come first in a PL/SQL stand alone file if it is used. In what order should a open/fetch/loop set of commands in a PL/SQL block be implemented if you use the %NOTFOUND cursor variable in the exit when statement? Expected answer: OPEN then FETCH then LOOP followed by the exit when. Poor data dictionary or library cache hit ratios, getting error ORA-04031.