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What does 'input queue wait' really mean?
Trying to work out why queries are slow and I see for the same query run twice, one ran for 20 ms and the other for 1800 ms:
select statement_id,operator_name,operator_id,counter_value,counter_name from v_monitor.execution_engine_profiles where transaction_id=49539595942919366 and statement_id IN (32,33) and counter_name ilike('%(us)%'); statement_id | operator_name | operator_id | counter_value | counter_name --------------+---------------+-------------+---------------+------------------------ 32 | Root | 0 | 16 | execution time (us) 32 | Root | 0 | 19 | clock time (us) 32 | Root | 0 | 5405 | input queue wait (us) 32 | NewEENode | 1 | 36 | execution time (us) 32 | NewEENode | 1 | 38 | clock time (us) 32 | NewEENode | 1 | 0 | output queue wait (us) 32 | GroupByPipe | 2 | 10 | execution time (us) 32 | GroupByPipe | 2 | 14 | clock time (us) 32 | StorageUnion | 3 | 128 | execution time (us) 32 | StorageUnion | 3 | 1395 | clock time (us) 32 | GroupByPipe | 4 | 37 | execution time (us) 32 | GroupByPipe | 4 | 65 | clock time (us) 32 | ExprEval | 5 | 137 | execution time (us) 32 | ExprEval | 5 | 171 | clock time (us) 32 | Scan | 6 | 815 | execution time (us) 32 | Scan | 6 | 909 | clock time (us) 33 | Root | 0 | 12 | execution time (us) 33 | Root | 0 | 14 | clock time (us) 33 | Root | 0 | 1794434 | input queue wait (us) 33 | NewEENode | 1 | 87 | execution time (us) 33 | NewEENode | 1 | 3295 | clock time (us) 33 | NewEENode | 1 | 0 | output queue wait (us) 33 | GroupByPipe | 2 | 17 | execution time (us) 33 | GroupByPipe | 2 | 173 | clock time (us) 33 | StorageUnion | 3 | 151 | execution time (us) 33 | StorageUnion | 3 | 8938 | clock time (us) 33 | GroupByPipe | 4 | 61 | execution time (us) 33 | GroupByPipe | 4 | 173 | clock time (us) 33 | ExprEval | 5 | 265 | execution time (us) 33 | ExprEval | 5 | 905 | clock time (us) 33 | Scan | 6 | 994 | execution time (us) 33 | Scan | 6 | 3477 | clock time (us) (32 rows) The outstanding difference is the input queue wait value, but what does that value really mean and how do I make it more consistent? 0
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In your case, I can see that it is the Root operator. But as of now I'm not sure on what exactly the Root operator is, will update you when I get some idea.