You want to optimize a query on a partitioned table by combining partition pruning with an index scan. Which condition helps achieve this?

hard📝 Application Q9 of 15

PostgreSQL - Table Partitioning

AWHERE partition_key = '2023-06-01' AND indexed_column = 'value'

BWHERE LOWER(partition_key) = '2023-06-01' AND indexed_column = 'value'

CWHERE partition_key + INTERVAL '1 day' = '2023-06-02' AND indexed_column = 'value'

DWHERE random() > 0.5 AND indexed_column = 'value'

Step-by-Step Solution

Solution:

Step 1: Identify pruning-compatible condition
Direct equality on partition_key enables pruning; functions or expressions disable it.
Step 2: Combine with index scan
Adding condition on indexed_column allows index scan after pruning partitions.
Step 3: Evaluate options
WHERE partition_key = '2023-06-01' AND indexed_column = 'value' uses direct equality and indexed column, enabling pruning and index scan. Others use functions or expressions disabling pruning.
Final Answer:
WHERE partition_key = '2023-06-01' AND indexed_column = 'value' -> Option A
Quick Check:
Direct partition key equality + index condition = pruning + index scan [OK]

Quick Trick: Use direct partition key conditions plus indexed columns [OK]

Common Mistakes:

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