As computing power becomes increasingly distributed into the devices and infrastructure around us, the data generated by those devices will invariably play a larger role in our businesses and everyday lives.Cylance director of sales engineering Rich Thompson stops by the Information Week News Desk to share how the company uses artificial intelligence to identify unknown threats and stop the execution of an attack.I've got a data warehouse (oracle) where I need to set a column to the same value for all 700 million rows.I don't have admin access, or access to an admin, so this needs to be accomplished with basic sql and no temp table creates.Additionally, you will bypass the inefficient buffer cache during this massive operation. Think about the math involved in updating millions of rows on, for example, 1 million blocks (about 7.5 GB of table data).You will have to read each and every block into the buffer cache (I’ll assume a full table scan in this case).Hi, I have a table tab1 CREATE TABLE tab1 ( MDN NUMBER(10), SID NUMBER(5) ) another table tab2 : CREATE TABLE tab2 ( MDN NUMBER(10), SID NUMBER(5) ) Both table can have multiple records for a given MDN. I don't want to do this in a single update statement as both tables contain minimum of 60 millions of records.
If you're on 11g, drop the column and add it back as a NOT NULL column with a default value.UPDATE and DELETE are not for massive operations—the UNDO they must generate and the REDO that is generated as a result are overhead you don’t need for a massive batch operation.This is a good case for data definition language (DDL)—not data manipulation language (DML). And it will generate more Since the query you have shown in the question contains a subquery, this is doing a lookup on table b for every row that is being updated.The ability to the UPDATE depends on there being a "key-preserved join". It's a little hard to give a proper answer without some sort of DDL for the tables.The advantage of both of these statements is that they work on the whole set of data rather than updating one row at a time.