In MySQL HeatWave, you can explicitly exclude certain table columns
from being loaded into the MySQL HeatWave Cluster, by defining them with
the NOT SECONDARY
attribute. These columns
are typically not needed for analytic queries and are therefore
omitted to optimize memory usage and performance.
Ensure that the
enable_secondary_engine_statistics
system variables is set toON
.Check if you have the
SELECT
andINSERT
privileges for the table that you want to analyze. If not, ask your admin user to grant you the required privileges.
To identify table columns defined as NOT
SECONDARY
on the DB System, query the
EXTRA
column of the
INFORMATION_SCHEMA.COLUMNS
table.
Columns defined with the NOT SECONDARY
column attribute are not loaded into MySQL HeatWave when executing a
table load operation.
mysql> SELECT COLUMN_NAME, EXTRA
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME LIKE 't1' AND EXTRA LIKE '%NOT SECONDARY%';
+-------------+---------------+
| COLUMN_NAME | EXTRA |
+-------------+---------------+
| O_COMMENT | NOT SECONDARY |
+-------------+---------------+
You can also view columns defined as NOT
SECONDARY
for an individual table using
SHOW CREATE TABLE
.