Execution Plan Scan Hints Do Not Take Effect

Symptom

The execution plan scan hints are specified in GaussDB(DWS) but do not take effect.

Possible Causes

The hint syntax is incorrect. The scan hint syntax should contain /*+ indexscan(table_name index_name) */. In the picture, the plus sign (+) is missing.

For details about the syntax of plan hints, see Plan Hint Optimization Overview.

Handling Procedure

1. Add the /*+ indexscan(table_name index_name) */ format to the SELECT statement for the scan hint syntax.

   explain verbose
   select /*+ indexscan (vmall_oar.dm_page_lag_lead_result idx_mix)*/
   ......