In this article, we will explore some tips and tricks from experienced Oracle users.
These tips and tricks can help you get the most out of your Oracle database, and avoid some common pitfalls.
1) Use Views To Simplify Complex Queries:
When working with large databases, it is often necessary to run complex queries. Views can be very helpful in simplifying these queries. By creating a view, you can select a subset of data from a larger table, and then query that view as if it were a separate table. This can make complex queries much simpler to write and understand.
2) Use Materialized Views To Improve Performance:
Materialized views are similar to regular views, but they are stored in the database as actual tables. This can be very helpful in improving the performance of complex queries. When a query is run against a materialized view, the results are retrieved from the stored table, rather than being generated on the fly. This can make a big difference in performance, especially for large and complex queries.
3) Use bind variables to improve performance and avoid “hard parsing”:
When Oracle parses a SQL statement, it checks the syntax and looks for any potential errors. It also looks up any objects that are referenced in the statement, such as tables or columns. This process is known as “parsing.”
If a SQL statement is parsed multiple times, it can have a negative impact on performance. This is because Oracle has to do all of the work of parsing the statement each time it is run.
One way to avoid this problem is to use bind variables. Bind variables are placeholders that are used in SQL statements. When a statement is parsed, Oracle replaces the bind variables with actual values.
This has two major benefits. First, it means that the statement only needs to be parsed once. Second, it can help improve performance because Oracle can cache information about the statement and reuse it when the statement is run again.
4) Use indexes wisely:
Indexes are a common way to improve the performance of SQL queries. However, they can also have a negative impact on performance if they are not used wisely.
When creating an index, you should carefully consider which columns to index. Indexing too many columns can actually slow down performance because Oracle has to update the indexes every time a row is inserted, updated, or deleted.
It is also important to consider the structure of your data when choosing which columns to index. For example, if you have a column that contains mostly unique values, such as a customer ID, there is no need to index that column.
5) Use partitions wisely:
Partitions are a way of dividing a table into multiple pieces. This can be helpful in improving the performance of certain types of queries.
However, partitions can also have a negative impact on performance if they are not used wisely. Partitions should only be used for large tables, and only if the data in the table can be divided logically into partitions.
For example, a table that contains customer orders could be partitioned by customer ID this would make it easier to query specific customers’ orders, without having to scan the entire table.
6) Use Materialized Views Wisely:
Materialized views are similar to regular views, but they are stored in the database as actual tables. This can be very helpful in improving the performance of complex queries. When a query is run against a materialized view, the results are retrieved from the stored table, rather than being generated on the fly. This can make a big difference in performance, especially for large and complex queries.
7) Use the EXPLAIN PLAN statement to understand why a query is slow:
The EXPLAIN PLAN statement is a powerful tool that can be used to understand why a SQL query is slow. It can show you the execution plan that Oracle uses to run the query, and it can help you identify potential bottlenecks.
Conclusion:
Views can be a helpful way to improve the performance of SQL queries. However, it is important to use them wisely. Indexes and partitions can also be helpful in improving performance, but they should only be used if they are appropriate for the data and the query.
