PostgreSQL – How to view the Size of a Table

To delete the data from a table in PostgreSQL, you can use the DELETE statement without a WHERE clause. This will remove all rows from the table, effectively emptying it. Below is the basic syntax: DELETE FROM table_name; where table_name is the name of the table you want to delete the data from. After running…

To delete duplicate rows in PostgreSQL using a self-join, you can use the DELETE statement along with a self-join condition. Here’s the syntax: DELETE FROM your_table a USING your_table b WHERE a.column_name = b.column_name AND a.ctid < b.ctid; where your_table is the actual name of your table, and column_name is the column that you want…

To drop (delete) a table in PostgreSQL, you can use the DROP TABLE statement. Here’s the basic syntax: DROP TABLE table_name; where table_name is the name of the table you want to drop. Here’s an example of how to use this syntax to drop a table named my_table: DROP TABLE my_table; Be very cautious when…

You can count the number of rows in a table in PostgreSQL using the SELECT COUNT(*) query. Here’s how you can do it: SELECT COUNT(*) FROM table_name; Replace table_name with the name of the table for which you want to count the rows. When you run this query, PostgreSQL will return a single value, which…

To get the size of a PostgreSQL database, you can use a few different methods, including SQL queries and command-line utilities. Here are a couple of approaches: Using SQL Query You can use the following SQL query to get the size of a specific database in PostgreSQL: SELECT pg_size_pretty(pg_database_size(‘your_database_name’)) AS database_size; where your_database_name is the…

To add a NOT NULL constraint to an existing column in a PostgreSQL table, you can use the ALTER TABLE statement with the ALTER COLUMN clause. Here’s the basic syntax: ALTER TABLE table_name ALTER COLUMN column_name SET NOT NULL; where table_name is the name of the table you want to modify, and column_name is the…