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19 lines
724 B
Plaintext
19 lines
724 B
Plaintext
-- { echo }
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SELECT count() > 0 FROM system.stack_trace WHERE query_id != '' AND thread_name = 'TCPHandler';
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1
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-- opimization for not reading /proc/self/task/{}/comm and avoid sending signal
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SELECT countIf(thread_id > 0) > 0 FROM system.stack_trace;
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1
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-- optimization for trace
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SELECT length(trace) > 0 FROM system.stack_trace WHERE length(trace) > 0 LIMIT 1;
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1
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-- optimization for query_id
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SELECT length(query_id) > 0 FROM system.stack_trace WHERE query_id != '' AND thread_name = 'TCPHandler' LIMIT 1;
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1
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-- optimization for thread_name
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SELECT length(thread_name) > 0 FROM system.stack_trace WHERE thread_name != '' LIMIT 1;
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1
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-- enough rows (optimizations works "correctly")
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SELECT count() > 100 FROM system.stack_trace;
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1
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