SQL Archives - Shoumadip Das

Category: SQL

A Top-N query is used to retrieve the top or bottom N rows from an ordered set. Combining two Top-N…

INSERT APPEND BEGINDATA You can also specify the data directly inside the control file itself using BEGINDATA keyword. i.e Anything…

SQL*Loader allows you to load data from an external file into a table in the database. It can parse many…

The Oracle PARALLEL hint instructs the optimizer to use a specified number of concurrent servers (degree of parallelism, or DOP)…

Oracle employs several methods, known as access paths, to retrieve data for a SQL statement. Optimizer hints are comments within…

As of Oracle 12.1, you can now define invisible columns in relational tables. An invisible column is a user-defined hidden…

• Simple CASE statement evaluates a expression and executes the statement or sequence of statements associated with the first condition…

The SELECT FOR UPDATE statement is a special variation of the normal SELECT statement, which proactively issues row locks on…

Traditionally, performing a function on an indexed column in the where clause of a query guaranteed an index would not…

Reverse B-TREE key indexes reverses the bytes of the key value in the index to reduce Index block contention. Index…