BULK COLLECT is a performance-tuning feature of Oracle PL/SQL that lets you collect data from the database into PL/SQL arrays in a single operation. This can reduce the number of context switches between SQL and PL/SQL, and also can reduce network traffic.BULK COLLECT can be used with DML statements (such as INSERT, UPDATE, and DELETE) and with SELECT INTO statements. It is usually used with FORALL, which lets you insert or update multiple rows in one operation.When you use BULK COLLECT, you must declare an array in your PL/SQL block to hold the data. The array size can be fixed or variable. You can also specify the BULK_ROWCOUNT attribute of the cursor to limit the number of rows fetched by each fetch operation.BULK COLLECT is a feature of the Oracle PL/SQL programming language that allows programmers to more efficiently retrieve data from database tables. When retrieving data from a database table, BULK COLLECT can be used to fetch multiple rows at once, into an array, thereby reducing the number of round-trips between the application and the database. This can result in a significant performance improvement for some applications.The BULK COLLECT statement is used to fetch multiple rows into PL/SQL variables in a single operation. It can be used in both standalone and embedded SQL. The BULK COLLECT INTO clause must specify a record type that matches the structure of the table or cursor being queried, and the number of items in the INTO clause must match the number of columns being selected. When fetching into a collection, the collection must be big enough to hold all the rows that will be retrieved.BULK COLLECT is a performance-tuning feature of Oracle PL/SQL that can dramatically improve the speed of some SQL operations. It allows the PL/SQL engine to fetch multiple rows at once, rather than one row at a time, from a database cursor. When used judiciously, BULK COLLECT can improve the performance of PL/SQL code by several orders of magnitude.