フリー問題

問題文

A healthcare team notices that the planner keeps choosing a sort merge join for a table that is in fact small. The table was created by copying files into place, so the catalog holds no size information. What does the statistics statement give the planner?

選択肢

1. Running the statistics statement fills the catalog with the column names that the cost based planner reads.
2. Running the statistics statement fills the catalog with the row counts that the cost based planner reads.
3. Running the statistics statement fills the catalog with the file listings that the cost based planner reads.
4. Running the statistics statement fills the catalog with the codec flags that the cost based planner reads.