Re: Why a bitmap scan in this case?

On 12/19/24 20:09, Jon Zeppieri wrote:
> The table is freshly vacuumed. If I disable bitmap scans, it will do
> an index only scan, which performs better. For the bitmap heap scan,
> it says "Heap Blocks: exact=27393," whereas for the index only scan,
> it's "Heap Fetches: 27701."

So you have 100% heap fetches. Are you sure that your table is freshly 
vacuumed? Please note that VACUUM FULL doesn't create the visibility 
map, so you still have to run a plain VACUUM for this.