In PostgreSQL, the “\d” command, the “\d+” command, “information_schema”, and the “SELECT *” statements with the “FALSE” option are used to check the table’s structure. The “\d” and “\d+” are meta-commands and must be executed from the “SQL Shell” aka psql. Whil...
A single PostgreSQL server can contain many databases. Let’s explore three different approaches to list databases in PostgreSQL!
PostgreSQL is a database management system that uses the SQL querying language. It is a very stable and feature-rich database system that can be used to store the data from other applications on your VPS. In this article, we will discuss how to create and manage tables within ...
\z Modifications to Get All Tables in PostgreSQLAn alternative to the first solution would be to use:postgres-# \dt *.* This will return all the tables as what’s done before.We hope you learned the different ways in which we can display the INFORMATION_SCHEMA table for our users. We...
In this article, we saw how to check whether a column exists within a table. Overall, we worked with three different DBMSs: MSSQL MySQL PostgreSQL Each system has unique methods for performing the checks. Generally,these methods make use of metadata queries. Such checks help ensure database ...
reltuples provides an estimate of the row count for each table in PostgreSQL. Examples and Code Explanation: 1. Using pg_stat_user_tables to Retrieve Exact Row Counts Code: -- Select table names and row counts from pg_stat_user_tables ...
In PostgreSQL, an alias is a temporary alternative name for columns, tables, views, materialized views, etc. in a query. Aliases are assigned during query execution and aren't stored in the database or on disk. By using column aliases, the query output can become more meaningful. ...
The pg_stat_activity view in the PostgreSQL catalog tables gives you information regarding what a connection is doing and how long it has been in that state. If you run the query to get the values from the view, you get the following output for the state of each connection: ...
Example: How to Rename a Foreign Key in PostgreSQL? Consider the below-given steps to rename a column on which some other objects are dependent: Step 1: Fetch the tables Firstly, we will fetch the“article_details”and“author_details”tables using the“\d”command: ...
If you want to learn more about important features of PostgreSQL, you might want to check out one of my posts aboutsophisticated temporary tables which can be found here. Hans-Jürgen Schönig Founder & CEO of CYBERTEC Hans-Jürgen Schönig has worked with PostgreSQL since the 90's. He ...