フリー問題

問題文

A query scans nearly every micro-partition of a large table even though the predicate filters on a single day of data. What is the most likely cause?

選択肢

1. The warehouse is too small, because the number of micro-partitions that a statement reads is determined by the amount of compute the warehouse has available to it.
2. The result cache was cleared for that table, so the query had to read everything from storage instead of reusing the previous result.
3. The predicate uses a column that is not part of the table's primary key, and pruning works only on primary key columns.
4. The rows for that day are spread across many micro-partitions, so the metadata cannot rule most of them out before reading.