Hello, hackers! Sorry if this have already been discussed. I've had this idea some time ago and then successfully forgot about it until pgconf.ru, where I had a conversation with one of postgres users. His situation could be described as this: they have a table with id, timestamp and some other attributes, which is partitioned by (let's say) timestamp column. In different contexts they may want to filter the table either by id or by timestamp attribute (but not both). In this case pruning will only work for timestamp column.
The idea is to store min and max values of secondary attributes (like 'id' in the example above) for each partition somewhere in catalog and use it for partition pruning along with partitioning key. You can think of it as somewhat like BRIN index but for partitions. And it will have similar limitations. For example, we may benefit if secondary attribute values are monotonically increase or decrease, but would be unhelpful if they are scattered, or if table wasn't partitioned by range. I wanted to ask community's opinion would it be worth considering. Thanks! -- Ildar Musin i.mu...@postgrespro.ru
