Create constraints and indexes in Bitmap_Join_Indexes _ MySQL

Creating constraints and Indexes in Bitmap_Join_Indexes: When creating Bitmap Join Indexes, an ORA-25954 error occurs: a dimension primary key or a unique constraint condition is missing.

Cause: it is affected by constraints and indexes.

The test procedure is as follows:

Create table sales

As select * from sh. sales;

Create table MERS

As

Select * from sh. customers;

Create unique index CUST_ID_un on MERS (CUST_ID );

Create:

Bitmap Join Indexes

Create bitmap index sales_cust_gender_bjix

On sales (customers. cust_gender)

From sales, MERS

Where sales. cust_id = customers. cust_id;

The following error is reported:

Row 3 has an error:

ORA-25954: missing primary key or unique constraint for a dimension

Case study: Although the unique index of table MERS is defined here, this index does not have a unique constraint on table customers, that is, it does not mean that the table is unique; however, if the uniqueness constraint is added, no error is reported. The example is as follows:

SQL> ALTER TABLE MERS

2 MODIFY (cust_id CONSTRAINT customers_un unique );

The table has been changed.

SQL> create bitmap index sales_cust_gender_bjix

2 on sales (customers. cust_gender)

3 from sales, MERS

4 where sales. cust_id = customers. cust_id;

The index has been created.

Conclusion:

As long as the uniqueness constraint is added, no error is reported when you create BJI.