It looks to me that the same trick on Oracle can be used on MySQL/MariaDB - indexing a generated column. There's a comment on https://mariadb.com/kb/en/library/generated-columns/ to that effect.
P.S. Drizzle is long dead, the site isn't even up any more :) On 8 October 2017 at 12:38, Tim Allen <flip...@peregrinesalon.com> wrote: > I would love to see partial indexes supported. Great work! As far as > databases with Django support: > > - PostgreSQL supports partial indexes > - SQLite supports partial indexes > - SQL Server supports them, called "filtered indexes" > - Oracle: Sort of supports them: https://blog.jooq.org/ > 2017/01/18/how-to-emulate-partial-indexes-in-oracle/ > - MySQL/Maria/Drizzle: no support, AFAIK. > > Would we want to build partial indexes in for all databases, with the > caveat that they would be ignored on MySQL and perhaps Oracle? In those > cases, would be default to a full index? > > Regards, > > Tim > > On Saturday, October 7, 2017 at 4:56:00 AM UTC-4, Mattias Linnap wrote: >> >> Hi django-developers, >> >> I have written a package that implements PostgreSQL and SQLite partial >> indexes on top of the new class-based indexes: https://github.com/ma >> ttiaslinnap/django-partial-index >> The most common use case is partial unique constraints, but I have a few >> projects where non-unique partial indexes have turned out useful as well. >> >> I have a few questions on how to continue with this: >> >> 1. Right now the "where condition" expression is provided as a string, >> and has to be different for PostgreSQL and SQLite in some common cases (for >> example boolean literals). Is there a good abstraction for SQL expressions >> somewhere in Django internals that I could use instead, something similar >> to Q-expressions perhaps? In particular, to add validate_unique() support >> to ModelForms, I would need to be able to extract all fields that are >> mentioned in the where condition. >> 2. I've seen mentions of a "check constraints" support being in >> development (https://github.com/django/django/pull/7615). Will that >> include partial unique constraints, or is just for the per-column checks? >> 3. If separate, then it would be nice to one day get partial indexes >> merged into the contrib.postgres package. Do you have any suggestions on >> what needs to happen before that - more test coverage, more contributors, >> more users, or similar? >> >> Best, >> >> Mattias >> > -- > You received this message because you are subscribed to the Google Groups > "Django developers (Contributions to Django itself)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to django-developers+unsubscr...@googlegroups.com. > To post to this group, send email to django-developers@googlegroups.com. > Visit this group at https://groups.google.com/group/django-developers. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/django-developers/df13ff66-8033-4f91-b49a- > 081bfa28db00%40googlegroups.com > <https://groups.google.com/d/msgid/django-developers/df13ff66-8033-4f91-b49a-081bfa28db00%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Adam -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at https://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/CAMyDDM0qxu7aPuRGy1yGUgG6FJbNHj%2Bnt3PyjY3FPnfCRuMGjw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
