On 2017-10-30 11:09, Stephen Russell wrote:
Less efficient indexes? Are you talking about space in a db compared to an int for a pointer or are you saying that the time to isolate the data on that row because of the data type of the pointer? The flip side is data insertion.
Can you tell us why you use less efficient?
Not sure of your wording, if you meant exactly that or not, so let me try to respond:
I like the guid v(40) indexes because if ever I needed to combine data, I'm not running into duplicate keys. Plus, I like defining the key ahead of time and having complete control so I can work with parent/child/grandchild datasets easier (than if I had to contend with auto-inc keys). The negative of this approach as I understood it is that the since the index is 4x larger in size than a 4-byte integer key, it would not be as efficient in memory, and the index tree needs reindexing more often so as to be balanced.
Plenty of good article on the interweb discussing both: http://www.ovaistariq.net/733/understanding-btree-indexes-and-how-they-impac... https://blog.codinghorror.com/primary-keys-ids-versus-guids/ http://web.archive.org/web/20150511162734/http://databases.aspfaq.com/databa...
I think I'll stick with app-generated GUIDs though for the portability and no-collision benefit if I merged/move data. I also want to do replication where their database is stored locally but then replicates to a master database outside their office.