#27719: Add queryset.alias() to mimic .annotate() for aggregations without
loading
data
-------------------------------------+-------------------------------------
Reporter: Marc | Owner: nobody
Tamlyn |
Type: New | Status: new
feature |
Component: Database | Version: master
layer (models, ORM) |
Severity: Normal | Keywords:
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
At the moment the Expressions API currently does not allow creating a
value for later use in the query without returning that data from the
database. In some cases this can be quite expensive over the pipe, and can
also influence query execution where functional indexes are involved. I
would like to introduce an API like `alias()`, which does the same thing
as `annotate()` to allow reuse in later querysets but doesn't return the
value.
To be explicit, we are changing a query from one of the form:
`SELECT to_tsvector('english', "some_field"), "some", "other", "fields"
FROM "table" WHERE to_tsvector('english', "some_field") @@
plainto_tsquery("search term") ... LIMIT 10;`
to one of the form:
`SELECT "some", "other", "fields" FROM "table" WHERE
to_tsvector('english', "some_field") @@ plainto_tsquery("search term") ...
LIMIT 10;`
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Ticket URL: <https://code.djangoproject.com/ticket/27719>
Django <https://code.djangoproject.com/>
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