10 Key PostgreSQL Schema Best Practices to Master Database Organization and Performance

PostgreSQL Schema Best Practices

When working on the PostgreSQL Schema Best Practices material, a PostgreSQL schema is a way of organizing the tables, views, indexes, functions, sequences, and other objects of the database into logical groups. These objects may be the tables, views, indexes, functions, sequences, and so on. The acceptance of PostgreSQL Schema Best Practices brings significant flexibility for the database administrators and developers to manage their databases in a modular and hierarchical way which are also easily understandable and maintainable.

Adhering to PostgreSQL schema Best Practices exactly will help you in these and other aspects to achieve the descendant of the strategies you make scalable, faster-running, and user-friendly databases for your applications. The both provided schemas are an equally useful term which in this case you can fully rely upon. Moreover the use of PostgreSQL schema best practices may act as the method of controlling the malicious attack directly through the browsing without the effacement of crucial data.

This walkthrough will cover the most important PostgreSQL Schema Best Practices from basic to advanced. We will give an overview of the concept of schemas and the ways to create and manage them through the use of PostgreSQL commands like CREATE SCHEMA, DROP SCHEMA, and ALTER SCHEMA. Thus, the following PostgreSQL Schema Best Practices are going to guarantee the schema design of yours to be both the smallest, therefore, most easily maintainable. Optionally, one could use of PostgreSQL Schema Best Practices in applications in the real world to enhance the database management strategy of theirs; these could be included in the list of examples.

Through these PostgreSQL Schema Best Practices you will now be able to structure your database schemas in a way that will lead to their long life and better performance.

1. Understanding PostgreSQL Schema Best Practices

A PostgreSQL schema is the core of the database structure. A schema is a collection of database objects that is stored within a namespace, in this case, a schema is a construct of logical division of a database. You can think of it as a directory that holds the smallest objects such as tables, indexes, views, functions, and many others instead of files. Schemas are designed for the logical grouping of these objects so one can easily interact with them, especially when dealing with a database that has many of these objects.

Each schema in PostgreSQL is assigned to a user or role, and the permissions for access can be managed. A public schema comes with a PostgreSQL database by default. In a database without specifying a schema, an object is created in the public schema by default.

In addition to the organization capabilities, schemas are also being used to avoid name collision errors. For example, you can have a table named users in both schema1 and schema2, and they can coexist without conflict because they reside in different namespaces.

2. PostgreSQL Create Schema

• The CREATE SCHEMA command in PostgreSQL is employed to create a new schema.
• Define a schema in the database by using the following names (schema name) as well as, optionally, the schema owner.
• Usually, the schema created is done by the default user who will procedure the CREATE SCHEMA statement.
• However, the owner can be changed as appropriated.

2.1 Syntax for Creating a Schema

CREATE SCHEMA schema_name;

• To create a schema with a specific owner:

CREATE SCHEMA schema_name AUTHORIZATION user_name;

• Where schema_name is the desired schema name to be created and user_name is the owner of that schema.

2.2 Example: Creating a Schema

• For the sake of this example, we will illustrate the steps taken to create a schema for a database that supports e-commerce.

— Creating the schema ‘ecommerce’

CREATE SCHEMA ecommerce;

• The word this is in this sentence refers to the schema ecommerce. We are then able to create tables, views, and other objects under the schema ecommerce.

— Creating a table inside the ‘ecommerce’ schema

CREATE TABLE ecommerce.products (

product_id serial PRIMARY KEY,

product_name varchar(100) NOT NULL,

price numeric(10, 2) NOT NULL

);

• This situation is an example of a scenario where a products table has been made with the e-commerce schema. Let it be known that we added the schema name as a prefix to the table so as to reference the table (i.e., ecommerce.products).

2.3 Example: Creating a Schema with a Specific Owner

• In case you want to give ownership of the schema to a specific user, you are able to develop the AUTHORIZATION clause.
• Here’s a schema to which the user account admin_user is assigned:

CREATE SCHEMA ecommerce AUTHORIZATION admin_user;

• As a result of this command, a new schema called ecommerce will be created, and admin_user will possess all its objects.

3. PostgreSQL Drop Schema

• The DROP SCHEMA command in PostgreSQL gives the programmer a way to dispose of a schema and/or the objects that lie beneath it.
• In the case of a schema that has objects like tables or views, they are removed when the whole schema is dropped.

3.1 Syntax for Dropping a Schema

DROP SCHEMA schema_name;

• In case you want to delete these objects completely with the schema (e.g., tables, views, functions), you have to write CASCADE after theCROSS option.
• In this way, it is possible to auto-delete all the objects on the schema.

DROP SCHEMA schema_name CASCADE;

• On the flip side, in case you want to only drop the schema if it is empty (that is, it has no objects in it), you can resort to the use of the RESTRICT option.
• Inside, the use of the DEFAULT command also denotes RESTRICT to be employed in the cases where the schema is not empty; thus, it will forbid the schema from being dropped because of its object’s existence.

DROP SCHEMA schema_name RESTRICT;

3.2 Example: Dropping a Schema

• We might say that we need to drop a revenue schema that we created before, but only if the schema is empty:

— Dropping the ‘ecommerce’ schema only if it is empty

DROP SCHEMA ecommerce RESTRICT;

• If the schema is populated, i.e., it contains other objects (e.g., tables, views), PostgreSQL will throw an error, and the schema will not be dropped.
• To reshape the schema will all the included objects in deletion mode, employ the CASCADE alternative:

— Dropping the ‘ecommerce’ schema and all its objects

DROP SCHEMA ecommerce CASCADE;

4. PostgreSQL ALTER Schema

• The ALTER SCHEMA command in PostgreSQL is the command used to make modifications to an existing schema.
• You may use this command to change the name of a schema, alter its owner, or manipulate the attributes linked to the schema.

4.1 Syntax for Altering a Schema

ALTER SCHEMA schema_name RENAME TO new_schema_name;

• It performs the process of renaming the existing schema to a new name with this command.
• To change the owner of a schema separately:

ALTER SCHEMA schema_name OWNER TO new_owner;

4.2 Example: Renaming a Schema

• Assume that we have to change, for example, the ecommerce schema name to online_store. Here’s the process to be followed:

— Renaming the ‘ecommerce’ schema to ‘online_store’

ALTER SCHEMA ecommerce RENAME TO online_store;

• Later on, items of old ecommerce schema can be found under the new label, online_store, as well.

4.3 Example: Change of Schema Owner

• When you are eager to change the ownership of a schema to another user, you can opt for the OWNER TO clause.
• Supposing, for example, you would like to swap the owner of the online_store schema with store_admin; you should use the given command:

— Change the owner of the ‘online_store’ schema

ALTER SCHEMA online_store OWNER TO store_admin;

5. Schema and Access Control

• One of the main reasons why the schema in PostgreSQL is so important is that it provides an additional level of accountability.
• Access permissions could be handled at the schema level, that is, you could give or deny certain rights to users or roles.
• These access rights will be automatically passed down to the objects inside the schema.

5.1 Example: Granting Permissions on a Schema

• If you want to give selective permissions on a schema to a user, then you can use the GRANT statement.
• E.g., To allow the user user1 to create objects within the online_store scheme the following way:

— Granting the CREATE privilege on the schema to a user

GRANT CREATE ON SCHEMA online_store TO user1;

• This would empower user1 to create the objects (e.g. tables and views) within the online_store schema.

5.2 Example: Revoking Permissions on a Schema

• To revoke the permissions previously given, one uses the REVOKE command. For example, to suspend the creation of in-line_store schema items by the user1, here is the command:

— Revoking the CREATE privilege on the schema from a user

REVOKE CREATE ON SCHEMA online_store FROM user1;

6. Practical Use Cases of Schemas in PostgreSQL

6.1 Multi-Tenant Databases

• Databases are very practical to work with when it comes to multi-tenant systems of database, where each tenant can have his single set of database objects but still use the same database as another.
• For instance, in a SaaS application, the schema for each customer may consist of their own data.

— Create schemas for different tenants (customers)

CREATE SCHEMA customer1;

CREATE SCHEMA customer2;

• Thus, each tenant has their own separate database and all data is kept quarantined, improving security and access control, although they also have the same database.

6.2 Organizing Database Objects

• In large databases, the thing that can simplify the management of a database is if you put the database object in by function.
• A database object might contain, for example, all employee-related data in the hr schema, whereas the sales schema could maintain customer data and sales transactions.
• Accounts are managed through the finance database object

— Create schemas to organize different functional areas

CREATE SCHEMA hr;

CREATE SCHEMA sales;

CREATE SCHEMA finance;

6.3 Handling Versioning of Database Structures

• The schemas are for database structures duration.
• For example, you can have one schema for an application version 2 while still keeping version 1.
• Once the new version is fully deployed and tested, you can switch over to the new schema.

— Create schemas for different application versions

CREATE SCHEMA app_v1;

CREATE SCHEMA app_v2;