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Showing posts with the label data manipulation language

Disadvantages of materialized View in SQL

Following are the Disadvantages of materialized View in SQL 1.We can not perform any DML Operations on materialized View ,but you can perform DDL Operations like DROP.The thing is here it stores the all records even if it is duplicate or non-duplicates,especially which we are using aggregate values.For example daily loads,monthly loads,yearly loads.such cases it would be very helpful storing of entire data if it is new or old. The disadvantage is takes space Can only be based on a simple Select if you require real time data. maintaining the materialized View  Logs has an overhead on the master system. 2.We can't perform DML on materialized View  because it is like snapshot or read only .it is mainly used for reporting purposes.A materialized view can be either read-only, updatable or writable. We Can't Perform DML on read-only but can Perform DML on updatable or writable. 3.On readable - we cant perform DML. on updatable- we can perform DML, we need to create the mate

Difference between collection and bulk binding in SQL

Following at the Differences between collection and bulk binding in SQL To retrieve multiple rows we can use cursors or bulk collections. Cursors row by row mechanism so performance decreased. But collections not row by row process all rows retrieved at time so performance increased. And bulk bind means doing DML(data manipulation language) operations as a bulk. By using for all statement we can do bulk-binding. If you want to do bulk-bind first should use bulk collections .