Creating Updateable Snapshots
Updateable snapshots require components at both the master site and the snapshot site. To illustrate the procedure, I’ll trace the steps required to create an updateable snapshot on the table SPROCKET.DAILY_SALES defined as follows:
SQL> desc daily_sales Name Null? Type ---------------- -------- ---- SALES_ID NOT NULL NUMBER(9) DISTRIBUTOR_ID NOT NULL NUMBER(6) PRODUCT_ID NOT NULL NUMBER(9) UNITS NOT NULL NUMBER(9,2) REGION NOT NULL VARCHAR2(3) AUDIT_DATE NOT NULL DATE AUDIT_USER NOT NULL VARCHAR2(30) GLOBAL_NAME NOT NULL VARCHAR2(20)
Each retail outlet of the fictitious Bigwheel Bicycle company updates a local snapshot of this table with each customer purchase. The outlet stores send their data back to the headquarters database each evening. For the purposes of our example, suppose that the headquarters database is named PHQS.BIGWHEEL.COM and that the retail store’s database is named PSFO.BIGWHEEL.COM.
Before creatingupdateable snapshots, the master and snapshot
databases must be configured for replication as described in Chapter 12. In addition to running the
catrep.sql scripts at both sites, you must ensure the
Replication administrator accounts exist with proper privileges at the master and all snapshot sites. (Typically, the replication administrator account is REPADMIN.)
Database links must be in place. The links from the snapshot site to the master site must connect to an account that either is the owner ...