Vitesse DB is 100% PostgreSQL in all aspects; the only difference is speed of query execution. Therefore, please refer to the PostgreSQL website for SQL or operational documentation. In the following, we will only list items pertinent to Vitesse DB.

GUCS

vitesse.enable

Boolean flag to enable Vitesse Engine. If the flag is OFF, Vitesse Engine will pass all queries to PostgreSQL. If the flag is ON, Vitesse Engine will attempt to compile and execute the query. The default is ON.

vitesse.last

Indicator showing if the last query was handled by Vitesse Engine. This guc is informational only.

vitesse.license

Show the Vitesse Engine license information.

vitesse.log_level

Log messages from Vitesse Engine. Set to 0 for no messages, 1 for error messages only, 2 for notices, 3 for informational messages. The default is 0.

vitesse.threshold

Specifies the threshold cost of a query, below which Vitesse Engine will not attempt to handle the query. As there is a cost to compile and optimize a query, it is not prudent to pay the price for trivial queries. This lever controls the tip-over point. Only queries costing more than the threshold will be handled by Vitesse Engine. The default is 200.

vitesse.version

Show the Vitesse DB version information.

DDL

By design, other than CREATE TABLE AS SELECT, all DDL are handled by PostgreSQL.

DML

By design, other than SELECT and INSERT, all DML clauses are handled by PostgreSQL.

For SELECT, the following specific cases are NOT supported by Vitesse Engine (but will be handled by PostgreSQL):

• CTE with recursion, although CTE in general are supported.
• lead and lag window functions, although other window functions are supported.
• Hash, GiST and GIN index, although B-tree is supported.
• Functions returning sets.