Using OptimizedTypedSet to Improve Map and Array Functions

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Function evaluation is a big part of projection CPU cost. Recently we optimized a set of functions that use TypedSet, e.g. map_concat, array_union, array_intersect, and array_except. By introducing a new OptimizedTypeSet, the above functions saw improvements in several dimensions: Furthermore, OptimizedTypeSet resolves the long standing issue of throwing EXCEEDED_FUNCTION_MEMORY_LIMIT for large incoming blocks: “The input…

Even Faster Unnest

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Unnest is a common operation in Facebook’s daily Presto workload. It converts an ARRAY, MAP, or ROW into a flat relation. Its original implementation used deep copy all the time and was very inefficient. In Unnest Operator Performance Enhancement with Dictionary Blocks, the author improved the Unnest operator by up to 10x in CPU and…