Experts in Postgres and Open Source Infrastructure

To find the list of users, databases, schemas, or tables, the meta-commands like “\du”, “\l”, “\dn”, and “\dt” are used, respectively.

psql is a command-line interface used to perform various database tasks efficiently. For instance, using psql different commands can be executed to access, create, delete, or update a database, table, schema, etc.

In Postgres, the TRUNCATE TABLE command only removes the table’s data and preserves the table’s structure. While the DROP TABLE command drops the table’s data and structure permanently.

regexp_matches() function takes in the string and the regular expression to be matched as an argument along with an optional flag and returns the first matched substring from the main string.

Use the “sudo apt install postgresql postgresql-contrib” command to install PostgreSQL from Debian 12’s default repository.

In Postgres, the meta-commands like “\d”, “\dt”, “\dv”, “\ds”, and “\df” are used to describe relations, tables, views, sequences, and functions, respectively.

A database object is an entity defined in a database and is used to store or reference data. In Postgres, database objects are created using the CREATE command.

The ARRAY_UPPER() function in PostgreSQL returns the upper bound of the array dimension or the highest index of an array.

The Postgres jsonb_to_record() function takes a top-level JSONB object, converts it into a table record/row, and returns it.

The json_populate_record() function in Postgres converts the JSON object into a data row. It populates the table record from the JSON object.