Shows generated Intermediate Representation (IR) code, identifying whether it is executed on GPU or CPU. This is primarily used internally by HEAVY.AI to monitor behavior.
EXPLAIN <STMT>
For example, when you use the EXPLAIN command on a basic statement, the utility returns 90 lines of IR code that is not meant to be human readable. However, at the top of the listing, a heading indicates whether it is IR for the CPU or IR for the GPU, which can be useful to know in some situations.
EXPLAIN CALCITE
Returns a relational algebra tree describing the high-level plan to execute the statement.
EXPLAIN CALCITE <STMT>
The table below lists the relational algebra classes used to describe the execution plan for a SQL statement.
For example, a SELECT statement is described as a table scan and projection.
If you add a sort order, the table projection is folded under a LogicalSort procedure.
omnisql> EXPLAIN calcite (SELECT*FROM movies ORDER BY title);ExplanationLogicalSort(sort0=[$1], dir0=[ASC]) LogicalProject(movieId=[$0], title=[$1], genres=[$2]) LogicalTableScan(TABLE=[[CATALOG, omnisci, MOVIES]])
When the SQL statement is simple, the EXPLAIN CALCITE version is actually less “human readable.” EXPLAIN CALCITE is more useful when you work with more complex SQL statements, like the one that follows. This query performs a scan on the BOOK table before scanning the BOOK_ORDER table.