count documents api

[abose]

There should be a way to get count of documents in store without doing a full database read. SQL count(primarykey) should do this in O(1). This should also support query format.

For Eg. Right now, there is no way to do getCount(publishedExtensions) without doing a full scan of the table.

let count = await countDocuments("tableName");
let count = await countDocuments("tableName", query, indexedFields);

[abose]

⚠️ Note on InnoDB counts
This API will trigger a full scan in InnoDB. Unlike MyISAM, InnoDB does not maintain exact row counts internally.

• COUNT(*) or COUNT(primary_key) on the whole table = full table (or PK index) scan.
• Even with an index + query filter, InnoDB must scan the matching index range, so large result sets can still be expensive.

This means countDocuments() should not be used for cheap O(1) row counts in InnoDB. It will always involve some level of row or index scanning, which can be inefficient on big tables.

So may not be a good idea to add this api.