Postgres and Open Source Experts

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

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.

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.

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.

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.

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.

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

In PostgreSQL, the IN operator is used with the collaboration of the WHERE clause to check the existence of a particular value in a list of values.

In Postgres, the HAVING clause is mostly used with the GROUP BY clause to filter the group/aggregate based on some specific condition.

In PostgreSQL, the DISTINCT keyword/clause is used within the SELECT statement to fetch the unique records from the result-set.