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MySQL HeatWave User Guide
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2.5.2.2 Running Auto Unload

Run Auto Unload in dryrun mode first to check for errors and warnings and to inspect the generated unload script. To unload a single schema in dryrun mode:

mysql> CALL sys.heatwave_unload(JSON_ARRAY("tpch"), JSON_OBJECT("mode","dryrun"));

In dryrun mode, Auto Unload sends the unload script to the heatwave_autopilot_report table only. See Section 6.1, “HeatWave Autopilot Report Table”.

If Auto Unload fails with an error, inspect the errors with a query to the heatwave_autopilot_report table.

mysql> SELECT log FROM sys.heatwave_autopilot_report
          WHERE type="error";

When Auto Unload finishes running, query the heatwave_autopilot_report table to check for warnings.

mysql> SELECT log FROM sys.heatwave_autopilot_report
          WHERE type="warn";

Issue the following query to inspect the unload script that was generated.

mysql> SELECT log->>"$.sql" AS "Unload Script"
          FROM sys.heatwave_autopilot_report 
          WHERE type = "sql" ORDER BY id;

Once you are satisfied with the Auto Unload CALL statement and the generated unload script, reissue the CALL statement in normal mode to unload the data into HeatWave. For example:

mysql> CALL sys.heatwave_unload(JSON_ARRAY("tpch"), JSON_OBJECT("mode","normal"));
Note

Retrieve DDL statements in a table or use the following statements to produce a list of DDL statements to easily copy and paste.

mysql> SET SESSION group_concat_max_len = 1000000;
mysql> SELECT GROUP_CONCAT(log->>"$.sql" SEPARATOR ' ')
          FROM sys.heatwave_autopilot_report
          WHERE type = "sql" ORDER BY id;

The time required to unload data depends on the data size.

Tables are unloaded in sequence, ordered by schema and table name. Unload-time errors are reported as they are encountered. If an error is encountered while unloading a table, the operation is not terminated. Auto Unload continues running, moving on to the next table.

When Auto Unload finishes running, it checks if tables are unloaded and shows a summary with the number of tables that were unloaded and the number of tables that failed to unload.