SQL API reference

SQL API supports the following commands as well as functions and operators.

If you’d like to propose a function or an operator to be supported in the SQL API, check the existing issues on GitHub. If there are no relevant issues, please file a new one.

SQL commands

`SELECT`

Synopsis:

SELECT select_expr [, ...]
  FROM from_item
    CROSS JOIN join_item
    ON join_criteria]*
  [ WHERE where_condition ]
  [ GROUP BY grouping_expression ]
  [ HAVING having_expression ]
  [ LIMIT number ] [ OFFSET number ];

SELECT retrieves rows from a cube. The FROM clause specifies one or more source cube tables for the SELECT. Qualification conditions can be added (via WHERE) to restrict the returned rows to a small subset of the original dataset. Example:

SELECT COUNT(*), orders.status, users.city
FROM orders
  CROSS JOIN users
WHERE city IN ('San Francisco', 'Los Angeles')
GROUP BY orders.status, users.city
HAVING status = 'shipped'
LIMIT 1 OFFSET 1;

`EXPLAIN`

Synopsis:

EXPLAIN [ ANALYZE ] statement

The EXPLAIN command displays the query execution plan that the Cube planner will generate for the supplied statement. The ANALYZE will execute statement and display actual runtime statistics, including the total elapsed time expended within each plan node and the total number of rows it actually returned. Example:

EXPLAIN WITH cte AS (
  SELECT o.count as count, p.name as product_name, p.description as product_description
  FROM orders o
    CROSS JOIN products p
)
SELECT COUNT(*) FROM cte;
   plan_type   |                                plan
---------------+---------------------------------------------------------------------
 logical_plan  | Projection: #COUNT(UInt8(1))                                       +
               |   Aggregate: groupBy=[[]], aggr=[[COUNT(UInt8(1))]]                +
               |     CubeScan: request={                                            +
               |   "measures": [                                                    +
               |     "orders.count"                                                 +
               |   ],                                                               +
               |   "dimensions": [                                                  +
               |     "products.name",                                               +
               |     "products.description"                                         +
               |   ],                                                               +
               |   "segments": []                                                   +
               | }
 physical_plan | ProjectionExec: expr=[COUNT(UInt8(1))@0 as COUNT(UInt8(1))]        +
               |   HashAggregateExec: mode=Final, gby=[], aggr=[COUNT(UInt8(1))]    +
               |     HashAggregateExec: mode=Partial, gby=[], aggr=[COUNT(UInt8(1))]+
               |       CubeScanExecutionPlan                                        +
               |
(2 rows)

With ANALYZE:

EXPLAIN ANALYZE WITH cte AS (
  SELECT o.count as count, p.name as product_name, p.description as product_description
  FROM orders o
    CROSS JOIN products p
)
SELECT COUNT(*) FROM cte;
     plan_type     |                                                                                plan
-------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Plan with Metrics | ProjectionExec: expr=[COUNT(UInt8(1))@0 as COUNT(UInt8(1))], metrics=[output_rows=1, elapsed_compute=541ns, spill_count=0, spilled_bytes=0, mem_used=0]           +
                   |   HashAggregateExec: mode=Final, gby=[], aggr=[COUNT(UInt8(1))], metrics=[output_rows=1, elapsed_compute=6.583µs, spill_count=0, spilled_bytes=0, mem_used=0]     +
                   |     HashAggregateExec: mode=Partial, gby=[], aggr=[COUNT(UInt8(1))], metrics=[output_rows=1, elapsed_compute=13.958µs, spill_count=0, spilled_bytes=0, mem_used=0]+
                   |       CubeScanExecutionPlan, metrics=[]                                                                                                                           +
                   |
(1 row)

`SHOW`

Synopsis:

SHOW name
SHOW ALL

Returns the value of a runtime parameter using name, or all runtime parameters if ALL is specified. Example:

SHOW timezone;
 setting
---------
 GMT
(1 row)

SHOW ALL;
            name             |    setting     | description
-----------------------------+----------------+-------------
 max_index_keys              | 32             |
 max_allowed_packet          | 67108864       |
 timezone                    | GMT            |
 client_min_messages         | NOTICE         |
 standard_conforming_strings | on             |
 extra_float_digits          | 1              |
 transaction_isolation       | read committed |
 application_name            | NULL           |
 lc_collate                  | en_US.utf8     |
(9 rows)

`SET`

Synopsis:

SET name TO value
SET name = value

The SET command changes a session variable to a new value. Use SET with the cube_cache session variable for cache control. You can also set the session time zone with SET TIME ZONE (or SET TIMEZONE):

SET TIME ZONE 'Europe/Rome';
SET TIME ZONE 'UTC';

Use DEFAULT to reset the time zone to its default. The LOCAL form (SET TIME ZONE LOCAL) is not supported.

SQL functions and operators

SQL API currently implements a subset of functions and operators supported by PostgreSQL. Additionally, it supports a few custom functions.