Add estimateCompressionRatio aggregate

Why it matters

The function helps users evaluate how effectively data can be compressed in their tables. This insight can assist in storage planning and optimizing data layouts for improved performance and reduced disk usage.

How to use it

Use the new aggregate function estimateCompressionRatio within queries to calculate the estimated compression ratio of a dataset. For example:

SELECT estimateCompressionRatio(column_name) FROM table_name;