Clickhouse SQL Compatibility
Clickhouse SQL syntax and functions as expected, except as noted below.
Differences and notes
||Returns null when dividing by
|Block functions operate on Clickhouse blocks of data, including
||Blocks are an internal concept to Hydrolix.
|Database and filesystem functions return values. The methods include
||These methods will throw and exception in Hydrolix. They are not relevant with the Hydrolix architecture.|
Only SELECT statement supported
Hydrolix currenly supports only SELECT through the Query API. Statements other than SELECT do not currently work in Hydrolix
Unsupported SELECT statement options
The following options are currently supported in Hydrolix
Untested Clickhouse Functions
Untested functions may work as expected, but are not currently part of the Hydrolix test suite.
Untested Function families
Functions in these Clickhouse function families are not currently being tested with Hydrolix.
- Array Functions
- External dictionary functions
- Splitting and Merging Strings and Arrays
- Introspection Functions
- JSON Functions
- Nullable aggregates
- Higher order functions
- Yandex.Metrica Dictionary Functions
These specific Clickhouse functions are not currently being tested with Hydrolix.
Unsupported Clickhouse functions
The following Clickhouse functions are part of the Hydrolix test suite, but not currently supported.