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You want to find all rows in messages where the body contains either 'error' or 'failure' but not both. Which to_tsquery expression with @@ operator will achieve this?
You want to find all rows in messages where the body contains either 'error' or 'failure' but not both. Which to_tsquery expression with @@ operator will achieve this?
hard📝 Application Q15 of 15
Step-by-Step Solution
Solution:
Step 1: Understand the requirement
We want rows containing 'error' or 'failure' but NOT both. This is an exclusive OR (XOR) condition.Step 2: Analyze the options
body @@ to_tsquery('(error | failure) & !(error & failure)') uses(error | failure) & !(error & failure), which means 'error or failure' AND NOT 'both error and failure'. This matches XOR logic.Step 3: Check other options
body @@ to_tsquery('error | failure & !error & !failure') is invalid syntax. body @@ to_tsquery('error | failure') matches any with 'error' or 'failure' including both. body @@ to_tsquery('error <-> failure') looks for 'error' immediately followed by 'failure'.Final Answer:
body @@ to_tsquery('(error | failure) & !(error & failure)') -> Option AQuick Check:
XOR = (A OR B) AND NOT (A AND B) [OK]
Quick Trick: Use (A | B) & !(A & B) for XOR in to_tsquery [OK]
Common Mistakes:
- Using simple OR instead of XOR
- Incorrect syntax for NOT operator
- Confusing proximity operator <-> with XOR
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