8 Byte (assuming 128 bit instead of 64 bit) but yeah.
It's not quite as simple as saving 8 bytes per row though. It's 8 bytes for the UUID, plus 8 for at least the PK, plus 8 more for any other keys the UUID is in.
Then you need to do that for any foreign-key-fields and keys those are in as well.
However, unless your table has very few non-uuid columns, the rest of the table size will dwarf the extra n*8 bytes here. And if you are storing any blobs (like pictures, documents etc) then frankly all the uuids won't add up to anything.
In summary, whether using uuids or not is right for you depends a Lot on your context. An Insert Only log table, with a billion rows, is a very different use case to say a list of employees or customers.
Generally I'm very comfortable with uuids for tables of say less than 100m rows. Very high inserting though suggests tables bigger than that, and perhaps benefits from different strategies.
When it comes to data stored in multiple places (think on-phone first, syncd to cloud, exported from multiple places to consolidated BI systems), uuids solve the Lot of problems.
It's not quite as simple as saving 8 bytes per row though. It's 8 bytes for the UUID, plus 8 for at least the PK, plus 8 more for any other keys the UUID is in.
Then you need to do that for any foreign-key-fields and keys those are in as well.
However, unless your table has very few non-uuid columns, the rest of the table size will dwarf the extra n*8 bytes here. And if you are storing any blobs (like pictures, documents etc) then frankly all the uuids won't add up to anything.
In summary, whether using uuids or not is right for you depends a Lot on your context. An Insert Only log table, with a billion rows, is a very different use case to say a list of employees or customers.
Generally I'm very comfortable with uuids for tables of say less than 100m rows. Very high inserting though suggests tables bigger than that, and perhaps benefits from different strategies.
When it comes to data stored in multiple places (think on-phone first, syncd to cloud, exported from multiple places to consolidated BI systems), uuids solve the Lot of problems.
Context is everything.