Was asked recently about optimization of interesting case. There was table like: =$ CREATE TABLE input_data ( category_id INT8, object_id INT8, interaction_ts timestamptz, interaction_type TEXT, interaction_count INT4 ); And there was a code that was grouping it all by sum()ing interaction_count per category, object, interaction_type, and timestamp truncated to hour. Basically, storing somewhere result of: … Continue reading "Grouping data into array of sums – fun with custom aggregates"
