| Overview | Overview of all functions. |
| Machine Learning | Functions for machine learning. |
| Introspection | Functions for introspection of ClickHouse. |
| arrayJoin | The arrayJoin function which takes each row and generates a set of rows (unfold) |
| Searching in Strings | Functions for searching within strings. |
| Hash | Hashing functions. |
| UUIDs | Functions for Working with UUIDs. |
| Time Series | Functions for time series data analysis. |
| Random Numbers | Functions for random number generation. |
| NLP | Functions for Natural Language Processing. |
| Conditional | Conditional functions. |
| Nullable | Functions for working with NULL. |
| Bit | Bitwise functions. |
| Time Window | Functions which return the inclusive lower and exclusive upper bound of the corresponding window. |
| IP Address | Functions for Working with IPv4 and IPv6 Addresses. |
| Splitting Strings | Functions for splitting strings. |
| Tuples | Functions for working with tuples. |
| String replacement | Functions for string replacement. |
| User Defined Functions | User Defined Functions. |
| Comparison | Comparison functions (equals, less, greater etc.) |
| Other | Functions which don't fit into any other category. |
| JSON | Functions for working with JSON. |
| URL | Functions for working with URLs. |
| Encoding | Functions for encoding data. |
| ULID | Functions for Working with ULID. |
| Maps | Functions for working with Maps. |
| Dictionaries | Functions for working with dictionaries. |
| IN | IN operators |
| Files | The file function. |
| Arrays | Functions for working with arrays. |
| String | Functions for working with Strings. (Functions for searching in strings and for replacing in strings are described separately.) |
| DateTime | Functions for working with dates and times. |
| Logical | Functions which perform logical operations on arguments of arbitrary numeric types. |
| Rounding | Functions for rounding. |
| uniqTheta | uniqTheta functions work on two uniqThetaSketch objects to do set operation calculations such as ∪ / ∩ / ×. |
| Distance | Functions for calculating vector norms, distances, normalization, and common operations in linear algebra and machine learning. |
| Bitmap | Functions for bitmaps. |
| Math | Mathematical functions. |
| Encryption | Functions for encryption. |
| Arithmetic | Functions for performing arithmetic on UInt, Int or Float types. |
| Embedded Dictionaries | Functions for Working with Embedded Dictionaries |
| Type Conversion | Functions for converting from one type to another type. |