Simon Willison’s Weblog

Items tagged sql in Mar

Filters: Month: Mar × sql ×

I called it normalization because then President Nixon was talking a lot about normalizing relations with China. I figured that if he could normalize relations, so could I.

Edgar F. Codd # 7th March 2020, 11:12 pm

Use The Index, Luke! Paging Through Results (via) The best explanation of keyset pagination I’ve seen. Keyset pagination is where instead of using OFFSET/LIMIT to return the next page of results you instead track the last seen value in the column you sort by and then return the next X results that follow it. This allows you to paginate to arbitrarily deep offsets within a table, whereas OFFSET/LIMIT requires first iterating across all preceding rows and tends to stop working well after the first few thousand results. # 29th March 2018, 5:30 pm

User-defined Order in SQL (via) This is a fun intellectual exercise: how can one efficiently implement a user-defined order in a SQL table? The obvious initial approach is to have an integer position column, but this means every subsequent row must be updated when an item changes position. Joe “begriffs” Nelson explores some clever alternatives, including floating point or decimal positions (allowing new items to be inserted at a midpoint between existing positions) and a new custom rational number type he buiIt as a PostgreSQL extension. # 21st March 2018, 2:07 pm

grant XXX on * ? (via) PostgreSQL doesn’t have a way to say “this user is allowed to select/update/etc on all tables in database X”. That kind of sucks. UPDATE: This is fixed in PostgreSQL 9, see the comments. # 16th March 2010, 6:26 pm

IronPython, MS SQL, and PEP 249. How Dino Viehland got Django’s ORM to talk to the .NET database layer. # 19th March 2008, 9:46 am

Queryset Implementation. Malcolm explains the work that has gone in to the queryset-refactor branch. Executive summary: Python’s ORM is probably a lot better at SQL than you are. # 19th March 2008, 9:43 am