SQL Archives - Shoumadip Das

Category: SQL

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…

BITMAP index are different from B-TREE index in the manner they store data. • B-TREE index stores data in tree…

The “ON PREBUILT TABLE” clause is used when you have already created a replicated table using “CTAS” and now want…

A join view is a view based on a join. Special considerations apply when you issue a DML(INSERT, UPDATE, or…