When we update a row and it does not fit entirely within the original database block due to the corresponding growth in size, we have a row migration. In the original place (where the row was stored) we have placed a pointer to the new location of the row.
In this recipe, we will see how to detect row migration issues, and how to avoid migrating rows in our tables. Follow these steps:
CREATE TABLE HR.BIG_ROWS ( id number NOT NULL, field1 char(2000) DEFAULT 'A' NOT NULL, field2 char(2000), field3 char(2000), field4 char(1000), constraint PK_BIG_ROWS primary key (ID)) TABLESPACE EXAMPLE PCTFREE 10;
INSERT INTO HR.BIG_ROWS (id) ...