Michael Smith created IMPALA-13166: -------------------------------------- Summary: Queries with many nested views are still slow Key: IMPALA-13166 URL: https://issues.apache.org/jira/browse/IMPALA-13166 Project: IMPALA Issue Type: Improvement Components: Frontend Affects Versions: Impala 4.4.0 Reporter: Michael Smith
Further profiling on the query from IMPALA-12800 - and a larger version of the same - show significant time spent in {{Analyzer#registerSlotRef}}. The bulk of the work here is in checking whether a {{SlotDescriptor}} exists in the current {{TupleDescriptor}}, both because {{Path#getFullyQualifiedRawPath}} is expensive and because equals on the resulting list is expensive (especially repeated over every {{SlotDescriptor}} in the {{TupleDescriptor}}. There's room for improvement here: 1. avoid copying {{rawPath_}} every time we call {{getFullyQualifiedRawPath}} 2. use a map to identify whether a {{SlotDescriptor}} already exists at {{Path}} in the current {{TupleDescriptor}} 3 other small improvements may exist around memory allocation -- This message was sent by Atlassian Jira (v8.20.10#820010)