> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oxla.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

Besides [math](/sql-reference/sql-functions/math-functions/overview), [aggregate](/sql-reference/sql-functions/aggregate-functions/overview), [window](/sql-reference/sql-functions/window-functions/overview), [string](/sql-reference/sql-functions/string-functions/overview), [timestamp](/sql-reference/sql-functions/timestamp-functions/overview), [JSON](/sql-reference/sql-functions/json-functions/overview) and [trigonometric](/sql-reference/sql-functions/trigonometric-functions) functions we also provide support for other functions. The list of them can be found below:

| **Function**                                                                                                         | **Description**                                                                                                               |
| -------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| [coalesce()](/sql-reference/sql-functions/other-functions/coalesce)                                                  | Returns the first argument that is not null, while the remaining arguments from the first non-null argument are not evaluated |
| [current\_database()](/sql-reference/sql-functions/other-functions/current-database)                                 | Returns the current database's name                                                                                           |
| [current\_schema()](/sql-reference/sql-functions/other-functions/current-schema)                                    | Returns the schema's name (first in the search path)                                                                          |
| [has\_schema\_privilege()](/sql-reference/sql-functions/other-functions/has-schema-privillege)                       | Checks whether the current user has specific privileges on a schema                                                           |
| [nullif()](/sql-reference/sql-functions/other-functions/nullif)                                                      | Replaces a given value with null if it matches a specific criterion                                                           |
| [pg\_get\_expr()](/sql-reference/sql-functions/other-functions/pg-get-expr)                                          | Retrieves the internal form of an individual expression (such as the default value for a column)                              |
| [pg\_total\_relation\_size()](/sql-reference/sql-functions/other-functions/pg-total-relation-size)                   | Retrieves the size of a table                                                                                                 |
| [pg\_typeof()](/sql-reference/sql-functions/other-functions/pg-typeof)                                               | Retrieves the data type of any given value                                                                                    |
| [pg\_encoding\_to\_char()](/sql-reference/sql-functions/other-functions/pg-encoding-to-char)                         | Converts an encoding internal identifier to a human-readable name                                                             |
| [pg\_get\_indexdef()](/sql-reference/sql-functions/other-functions/pg-get-indexdef)                                  | Reconstructs the PostgreSQL command used to retrieve the definition of a specified index                                      |
| [pg\_get\_userbyid()](/sql-reference/sql-functions/other-functions/pg-get-userbyid)                                  | Retrieves that name of a user (role) given its unique identifier (OID)                                                        |
| [pg\_relation\_is\_publishable()](/sql-reference/sql-functions/other-functions/pg-relation-is-publishable)           | Determines whether a specified relation (table) can be published in a publication                                             |
| [pg\_size\_pretty()](/sql-reference/sql-functions/other-functions/pg-size-pretty)                                    | Converts sizes in bytes into a human-readable format                                                                          |
| [pg\_table\_size()](/sql-reference/sql-functions/other-functions/pg-table-size)                                      | Retrieves that size of a specific table, including its associated storage components but excluding indexes                    |
| [pg\_table\_is\_visible()](/sql-reference/sql-functions/other-functions/pg-table-is-visible)                         | Checks whether a specified table (or other database object) is visible in the current schema search path                      |
| [pg\_get\_constraintdef()](/sql-reference/sql-functions/other-functions/pg-get-constraintdef)                        | Retrieves the definition of a specific constraint in a human-readable format                                                  |
| [pg\_get\_statisticsobjdef\_columns()](/sql-reference/sql-functions/other-functions/pg-get-statisticsobjdef-columns) | Retrieves the definitions of columns associated with a specified statistics object                                            |
| [obj\_description()](/sql-reference/sql-functions/other-functions/obj-description)                                   | Returns the comment associated with a specific database object                                                                |
| [col\_description()](/sql-reference/sql-functions/other-functions/col-description)                                   | Retrieves the comment associated with a specified table column based on its name                                              |
| [shobj\_description()](/sql-reference/sql-functions/other-functions/shobj-description)                               | Retrieves the comment associated with a shared database object                                                                |
| [pg\_backend\_pid()](/sql-reference/sql-functions/other-functions/pg-backend-pid)                                    | Returns the process ID (PID) of Oxla’s node handling the current session                                                      |