Database efficient updating

09 Mar

i have huge amount of data in my internal table , how to use update statement in this case . When you are updating the majority of rows in a table, using Create Table As Select (CTAS) is often more efficient performance than a standard update. A language called SQL has been developed to allow programmers to 'Insert', 'Update', 'Delete', 'Create', 'Drop' table records.Far more complicated queries can be written that can extract data from many tables at once. When a person logs on with their username and password, the system can then limit access only to those tables whose records they are authorised to view.https://com/t5/SAS-Procedures/Efficiently-updating-Sql-server-Table-using-SAS-Datase... what is the efficient way of updating data to database table . one is key field and suppose 20 th field i want to change . I have data for only 2 fields , i.e for ( 1 st and last 20 th field ) .i can't use update statement in loop , as it is not good practice(hits database several times ) it effects all the 20 fields for particular record .You should evaluate each tip as it applies to your specific application running on your specific hardware. (21 printed pages)Dan Haught, Executive Vice President of FMS, Inc., and Luke Chung, President of FMS, Inc.

Currently I am trying to delete entire records based on a Key field and re-insert the data.

Some of the tips might contradict other tips, but they are offered because bottlenecks differ in each situation.

Some tips might make things run faster on your system, while others degrade performance.

For example, a receptionist would be able to view employee location and contact details but not their salary. By having data held in separate tables, it is simple to add records that are not yet needed but may be in the future.

A salesman may see his team's sales performance but not competing teams. For example, the city table could be expanded to include every city and town in the country, even though no other records are using them all as yet.