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[TRAFODION-2575] Truncate long strings when computing USTAT aggregates #1044
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Check Test Started: https://jenkins.esgyn.com/job/Check-PR-master/1702/ |
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Test Passed. https://jenkins.esgyn.com/job/Check-PR-master/1702/ |
selvaganesang
approved these changes
Apr 5, 2017
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This change affects the SELECTs that UPDATE STATISTICS generates when computing aggregates on long character and varchar columns. We now truncate the string before doing aggregation. (Note: We already do this in other code paths in UPDATE STATISTICS -- namely internal sorts and sample table population. This particular code path was overlooked.)
Besides improving performance, this will avoid UPDATE STATISTICS failing due to lingering engine issues concerning long varchars and sorts.