How to implement parallelism with multiple tables in Oracle?

In Oracle database, parallel processing can be implemented to handle multiple tables simultaneously.

1. To parallel process a single table: you can use the ALTER TABLE statement to set the table’s degree of parallelism, for example:

ALTER TABLE table_name PARALLEL (DEGREE 4);

This will enable the table_name table to use four parallel processes to speed up queries during execution.

1. To perform parallel processing on the entire database, you can use the ALTER SYSTEM statement to set the database’s degree of parallelism. For example:

ALTER SYSTEM SET PARALLEL_MAX_SERVERS = 10;

This will allow the database system to run a maximum of 10 parallel queries simultaneously.

1. To parallelize the processing of a specific SQL statement: You can specify the degree of parallelism using HINTS in the SQL statement, for example:

SELECT /*+ parallel(table_name, 4) */ column1, column2
FROM table_name;

This will speed up the query by using 4 parallel processes during execution.

In general, the parallel processing feature of Oracle database can be utilized to improve query performance by setting the parallelism of tables, databases, or SQL statements for parallel processing multiple tables.