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

# Tabular operators

> This section explains how to use and combine tabular operators in APL.

The table summarizes the tabular operators available in APL.

| Function                                                           | Description                                                                                                                                               |
| ------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [count](/apl/tabular-operators/count-operator)                     | Returns an integer representing the total number of records in the dataset.                                                                               |
| [distinct](/apl/tabular-operators/distinct-operator)               | Returns a dataset with unique values from the specified fields, removing any duplicate entries.                                                           |
| [extend](/apl/tabular-operators/extend-operator)                   | Returns the original dataset with one or more new fields appended, based on the defined expressions.                                                      |
| [extend-valid](/apl/tabular-operators/extend-valid-operator)       | Returns a table where the specified fields are extended with new values based on the given expression for valid rows.                                     |
| [externaldata](/apl/tabular-operators/externaldata-operator)       | Returns a table with the specified schema, containing data retrieved from an external source.                                                             |
| [getschema](/apl/tabular-operators/getschema-operator)             | Returns the schema of the input, including field names and their data types                                                                               |
| [join](/apl/tabular-operators/join-operator)                       | Returns a dataset containing rows from two different tables based on conditions.                                                                          |
| [limit](/apl/tabular-operators/limit-operator)                     | Returns the top N rows from the input dataset.                                                                                                            |
| [lookup](/apl/tabular-operators/lookup-operator)                   | Returns a dataset where rows from one dataset are enriched with matching columns from a lookup table based on conditions.                                 |
| [make-series](/apl/tabular-operators/make-series)                  | Returns a dataset where the specified field is aggregated into a time series.                                                                             |
| [mv-expand](/apl/tabular-operators/mv-expand)                      | Returns a dataset where the specified field is expanded into multiple rows.                                                                               |
| [order](/apl/tabular-operators/order-operator)                     | Returns the input dataset, sorted according to the specified fields and order.                                                                            |
| [parse](/apl/tabular-operators/parse-operator)                     | Returns the input dataset with new fields added based on the specified parsing pattern.                                                                   |
| [parse-kv](/apl/tabular-operators/parse-kv)                        | Returns a dataset where key-value pairs are extracted from a string field into individual columns.                                                        |
| [parse-where](/apl/tabular-operators/parse-where)                  | Returns a dataset where values from a string are extracted based on a pattern.                                                                            |
| [project](/apl/tabular-operators/project-operator)                 | Returns a dataset containing only the specified fields.                                                                                                   |
| [project-away](/apl/tabular-operators/project-away-operator)       | Returns the input dataset excluding the specified fields.                                                                                                 |
| [project-keep](/apl/tabular-operators/project-keep-operator)       | Returns a dataset with only the specified fields.                                                                                                         |
| [project-rename](/apl/tabular-operators/project-rename)            | Returns a dataset where the specified field is renamed according to the specified pattern.                                                                |
| [project-reorder](/apl/tabular-operators/project-reorder-operator) | Returns a table with the specified fields reordered as requested followed by any unspecified fields in their original order.                              |
| [redact](/apl/tabular-operators/redact-operator)                   | Returns the input dataset with sensitive data replaced or hashed.                                                                                         |
| [sample](/apl/tabular-operators/sample-operator)                   | Returns a table containing the specified number of rows, selected randomly from the input dataset.                                                        |
| [search](/apl/tabular-operators/search-operator)                   | Returns all rows where the specified keyword appears in any field.                                                                                        |
| [sort](/apl/tabular-operators/sort-operator)                       | Returns a table with rows ordered based on the specified fields.                                                                                          |
| [summarize](/apl/tabular-operators/summarize-operator)             | Returns a table where each row represents a unique combination of values from the by fields, with the aggregated results calculated for the other fields. |
| [take](/apl/tabular-operators/take-operator)                       | Returns the specified number of rows from the dataset.                                                                                                    |
| [top](/apl/tabular-operators/top-operator)                         | Returns the top N rows from the dataset based on the specified sorting criteria.                                                                          |
| [union](/apl/tabular-operators/union-operator)                     | Returns all rows from the specified tables or queries.                                                                                                    |
| [where](/apl/tabular-operators/where-operator)                     | Returns a filtered dataset containing only the rows where the condition evaluates to true.                                                                |