Interview Questions

Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command.

TRUNCATE:

- TRUNCATE is faster and uses fewer system and transaction log resources than DELETE.

- TRUNCATE removes the data by deallocating the data pages used to store the table's data, and only the page deallocations are recorded in the transaction log.

- TRUNCATE removes all rows from a table, but the table structure, its columns, constraints, indexes and so on, remains. The counter used by an identity for new rows is reset to the seed for the column.

- You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY constraint. Because TRUNCATE TABLE is not logged, it cannot activate a trigger.

- TRUNCATE cannot be rolled back.

- TRUNCATE is DDL Command.

- TRUNCATE Resets identity of the table

DELETE:

- DELETE removes rows one at a time and records an entry in the transaction log for each deleted row.

- If you want to retain the identity counter, use DELETE instead. If you want to remove table definition and its data, use the DROP TABLE statement.

- DELETE Can be used with or without a WHERE clause

- DELETE Activates Triggers.

- DELETE can be rolled back.

- DELETE is DML Command.

- DELETE does not reset identity of the table.

Note: DELETE and TRUNCATE both can be rolled back when surrounded by TRANSACTION if the current session is not closed. If TRUNCATE is written in Query Editor surrounded by TRANSACTION and if session is closed, it can not be rolled back but DELETE can be rolled back.

A junction record is a member record type that allows for many-to-many relationship between its two owner records.

A savings account is the most basic type of account at a bank or credit union, allowing you to deposit money, keep the funds safe, and withdraw funds as needed. Savings accounts typically pay interest on your deposits, which helps you grow your money, but rates are relatively low on these low-risk accounts.

A checking account is a deposit account held at a financial institution that allows withdrawals and deposits. Also called demand accounts or transactional accounts, checking accounts are very liquid and can be accessed using checks, automated teller machines and electronic debits, among other methods.

Hence, Saving accounts usually offer higher interest rates than checking accounts.

Dual boot system allows you to install and maintain two operating systems on a single PC. The purpose for this is to maintain compatibility between older and newer software. For example, there maybe programs that only work under Windows 98, therefore having a dual boot system between Windows 98 and another version like Windows XP is a good choice.

At the time of updating the data warehouse, a lookup table is used. When placed on the fact table or warehouse based upon the primary key of the target, the update is takes place only by allowing new records or updated records depending upon the condition of lookup.

The materialized views are aggregate tables. It contains summarized data. For example, to generate sales reports on weekly or monthly or yearly basis instead of daily basis of an application, the date values are aggregated into week values, week values are aggregated into month values and month values into year values. To perform this process aggregate function is used.

The Debit balance recovery is usually made by raising a credit memo for the regular vendors. However if there are no future transactions from the supplier, we ask the vendor to send the check / make an EFT for the amount due from him.

Capital expenditures are capitalized because of the timing of their estimated benefits – the lemonade stand will benefit the firm for many years. The employees’ work, on the other hand, benefits the period in which the wages are generated only and should be expensed then. This is what differentiates an asset from an expense.

IDMS uses record locks to prevent another run-unit from updating the same record.