ColumnStore Execution Plan (CSEP) for MariaDB Enterprise ColumnStore

Overview

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

When the select handler receives the SELECT_LEX object, the select handler transforms the SELECT_LEX object 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();