Overview

The ColumnStore storage engine uses a ColumnStore Execution Plan (CSEP) to represent a query plan internally.

When the select handler receives the SELECT_LEX object, it transforms it into a CSEP as part of the query planning and optimization process. For additional information, see "MariaDB Enterprise ColumnStore Query Evaluation."

Viewing the CSEP

The CSEP for a given query can be viewed by performing the following:

1. Calling the calSetTrace(1) function:

SELECT calSetTrace(1);

2. Executing the query:

SELECT column1, column2
FROM columnstore_tab
WHERE column1 > '2020-04-01'
AND column1 < '2020-11-01';

3. Calling the calGetTrace() function:

SELECT calGetTrace();