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Education

This is the Education section of the Command Prompt Website. Here you will find blogs specifically about how to use Postgres and related technologies.

How to Rename a Table in PostgreSQL

In PostgreSQL, the RENAME TO clause is used with the collaboration of the ALTER TABLE statement to rename an already existing table.

How to Find Length of a String in PostgreSQL

In PostgreSQL, the LENGTH() function is used to find the length of a string. It takes a string as a parameter and returns the total number of characters.

How to Describe a Table in PostgreSQL

PostgreSQL provides several ways to describe a table. For example, the “\d” command, “\dt” command, and information_schema.

How to Delete Multiple Rows From a Table in PostgreSQL

In PostgreSQL, the DELETE statement is used with the collaboration of the WHERE clause and IN operator to delete multiple rows from a table.

PostgreSQL Indexes: B-Tree

In older versions of PostgreSQL, a B-tree index only contained pointers to the heap (table) of where a particular set of data could be accessed. This can cause performance issues because we first need to scan the index and then retrieve the data from the table. While Index scans are relatively cheap due to how they store data, table scans can be very expensive because the data can be at any place within the table. Though current enterprise methods of storage have alleviated much of this (SSD/NVME) performance impact, it still exists as we need to search for the data twice.

EnterpriseDB (EDB) vs PostgreSQL

Command Prompt understands that sometimes a closed source version of software provides better features than the Open Source counterparts. However, it is Command Prompt’s considerable experience over 25 years of providing expert PostgreSQL professional services and support that there are a minute number of closed source opportunities for PostgreSQL. The ecosystem and community is vibrant and continuing to solve the problems that enterprises face in a collaborative and Open Source way.

How to Insert Multiple Rows to a Table in PostgreSQL

The INSERT INTO statement is used to insert single or multiple rows into a table. To insert multiple rows in a table, the comma-separated syntax is used.

How to Use FETCH Clause in PostgreSQL

PostgreSQL provides a FETCH clause that is used to fetch/retrieve a part of rows returned by any query. It performs the same functionality as the LIMIT clause.

How to Use the Truncate Table Command in PostgreSQL

PostgreSQL provides several methods for truncating a specific table. The TRUNCATE TABLE command is one of them. It can be executed from the psql and pgAdmin.

How to Use BETWEEN Operator in PostgreSQL

In PostgreSQL, the BETWEEN operator is used to find a match against a range of values in SELECT, UPDATE, INSERT or DELETE queries.