Experts in Postgres and Open Source Infrastructure

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

To kill a process in Postgres, first, find the “pid” for all the processes, and then run the “pg_cancel_backend(pid)” and “pg_terminate_backend(pid)” commands.

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

In PostgreSQL, the jsonb_build_array() function takes the list of heterogeneous parameters and builds the JSONB array from them.

While writing the PostgreSQL queries, we sometimes need to use the string as identifiers. For this purpose, the string needs to be converted into the quantified identifier or properly quoted in the double quotation mark. In PostgreSQL, the quote_ident() function performs this task. The quote_ident() function gets a string as an argument and returns the same string properly double-quoted that can be used as a qualified identifier.

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The min_scale() function in Postgres returns the minimum precision or minimum number of decimal places that are necessary to accurately/completely express the number.

parse_ident() function splits the qualified identifier/argument into an array. It gets two parameters; the 1st is the argument that is to be split, and the 2nd is the strict mode

The json_each() function converts the top-level JSON object into the expanded key-value pairs. It accepts a JSON object as an input and converts and returns the expanded key-value pairs.

The JSON object is provided to the json_object_keys() function as an argument and it returns a column containing all the keys present in that particular JSON object.

The PostgreSQL quote_literal() function takes in a string and returns the same string enclosed with the single quotations.