Fixed #26709 -- Add class based indexes and CreateIndex operation #6726

akki · 2016-06-05T14:29:12Z

akki · 2016-06-06T05:49:40Z

django/db/models/indexes.py

+            tablespace_sql = " " + tablespace_sql
+
+        if not hasattr(self, 'name'):
+            self.name = schema._create_index_name(self.model, columns, suffix=suffix)


I am not sure if this is the right place to do this. Please have a look.

I do think this would be an obvious extension point for a subclass. Perhaps get_name()?

Should I write a new method get_name for Index class, which would create a name for the index independent of the schema. That way we will also have a uniform naming standard for the indexes, no matter which database the user uses.
But we might have to think about backward compatibility for this.

I think the name should be generated as part of the index class and should be database backend independent, otherwise your migrations would yield different names depending on the database used to generate the migrations.

mjtamlyn · 2016-06-06T19:59:25Z

I think this is broadly heading in the right direction. I'd like to see some example migration file code. Perhaps it's worth you setting up a simple project that we can build up the functionality but makes it easy to show that it works.

I think Index.as_sql is likely to need some refactoring as we make it more complex to support other options. In particular, I think that just using interpolation into schema.sql_create_index may prove too simplistic.

timgraham · 2016-06-08T17:42:14Z

About naming, we have:
CreateModel, DeleteModel
AddField, RemoveField,

It would be nice if the new operations were consistent with these names. I guess I'd go with AddIndex/RemoveIndex since, like fields, these are ancillary things to models -- other opinions?

timgraham · 2016-06-08T17:43:28Z

docs/ref/migration-operations.txt

+
+.. versionadded:: 1.11
+
+Creates a new index in the database table for the given model. ``model_name`` is the model's name


please wrap documentation lines at 79 characters

charettes · 2016-06-08T17:51:32Z

About naming, we have:
CreateModel, DeleteModel
AddField, RemoveField,

It would be nice if the new operations were consistent with these names. I guess I'd go with AddIndex/RemoveIndex since, like fields, these are ancillary things to models -- other opinions?

Agreed.

MarkusH · 2016-06-08T17:57:46Z

About naming, we have:
CreateModel, DeleteModel
AddField, RemoveField,

It would be nice if the new operations were consistent with these names. I guess I'd go with AddIndex/RemoveIndex since, like fields, these are ancillary things to models -- other opinions?

Agreed.

The names are derived from the SQL syntax which is CREATE INDEX and DROP INDEX. (CREATE TABLE / DROP TABLE, ADD COLUMN / DROP COLUMN [I agree the latter is poorly chosen]).

MarkusH · 2016-06-08T18:04:38Z

django/db/migrations/operations/models.py

+        model_state = state.models[app_label, self.model_name.lower()]
+        if not hasattr(self.index, 'model'):
+            self.index.model = state.apps.get_model(app_label, self.model_name)
+        if 'indexes' not in model_state.options:


This should never be the case. ModelState should have a default indexes = []

MarkusH · 2016-06-08T18:22:23Z

About naming, we have:
CreateModel, DeleteModel
AddField, RemoveField,

It would be nice if the new operations were consistent with these names. I guess I'd go with AddIndex/RemoveIndex since, like fields, these are ancillary things to models -- other opinions?

Agreed.

The names are derived from the SQL syntax which is CREATE INDEX and DROP INDEX. (CREATE TABLE / DROP TABLE, ADD COLUMN / DROP COLUMN [I agree the latter is poorly chosen]).

Well there we go, I don't even recall the names of the operations: it's CreateModel/DeleteModel and AddField/RemoveField. Anyhow, I find CreateIndex/DeleteIndex more intuitive (the keyword for the creating a new index is still the same as in SQL)

charettes · 2016-06-08T18:29:21Z

As indexes are related to a table/model I find AddIndex/RemoveIndex more appropriate.

Is there a reason not to use a single AlterIndexes operation analogous to AlterUniqueTogether/AlterIndexTogether?

MarkusH · 2016-06-08T18:51:50Z

docs/ref/models/index.txt

@@ -17,4 +17,5 @@ Model API reference. For introductory material, see :doc:`/topics/db/models`.
   lookups
   expressions
   conditional-expressions
+   indexes


I'd probably add this right after fields

akki · 2016-06-19T07:36:49Z

I have updated the algorithm.
Two indexes are identical if they are on the same table, have the same set of fields and are of the same type, so I have taken all three of these into account while hashing.
Also, I have alloted a share to each of them in the index name to keep it meaningful (as much as possible). I have given more share to table-name than field-name because table-name contains both app label and model name which usually makes it significantly larger than the column name.

timgraham · 2016-06-20T13:27:57Z

django/db/models/indexes.py

+        if index_name[0] == "_":
+            index_name = index_name[1:]
+        # It can't start with a number on Oracle, so prepend D if we need to
+        if index_name[0].isdigit():


Add validation that user-provided names don't start with a digit?

timgraham · 2016-06-20T13:53:42Z

Some cosmetic edits at akki#2.

akki · 2016-06-22T01:09:01Z

@timgraham Added tests for index names starting with numbers and underscores (regarding get_name) if that's what you meant.

timgraham · 2016-06-22T12:27:01Z

django/db/migrations/operations/models.py

+
+    def state_forwards(self, app_label, state):
+        model_state = state.models[app_label, self.model_name.lower()]
+        if not hasattr(self.index, 'model'):


I think this if statement can be removed as it doesn't seem to ever evaluate to False when running the test suite.

It does for new Index instances.

Oops, I forgot the not. Done.

Added corresponding migration operations - AddIndex, RemoveIndex to use them Thanks to markush, mjtamlyn, timgraham and charettes for reviewing and all the discussions.

akki · 2016-06-27T06:29:05Z

Updated PR addressing all comments. Rebased against master and squashed all commits.

timgraham · 2016-06-27T14:41:37Z

merged in 156e2d5, thanks!

akki force-pushed the gsoc-indexes branch from 93a2052 to a929506 Compare June 5, 2016 14:35

akki reviewed Jun 6, 2016
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akki force-pushed the gsoc-indexes branch from d032273 to 9cf4e43 Compare June 7, 2016 14:09

timgraham reviewed Jun 8, 2016
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MarkusH reviewed Jun 8, 2016
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akki force-pushed the gsoc-indexes branch from 8ddb5ea to 2f753f0 Compare June 19, 2016 05:35

timgraham reviewed Jun 20, 2016
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timgraham reviewed Jun 22, 2016
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Fixed #26709 -- Introduced class based indexes

1d97360

Added corresponding migration operations - AddIndex, RemoveIndex to use them Thanks to markush, mjtamlyn, timgraham and charettes for reviewing and all the discussions.

akki force-pushed the gsoc-indexes branch from 5855f17 to 1d97360 Compare June 25, 2016 16:46

timgraham closed this Jun 27, 2016

akki mentioned this pull request Aug 14, 2016

Improvements for models.Index class and it's operations #7081

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Fixed #26709 -- Add class based indexes and CreateIndex operation #6726

Fixed #26709 -- Add class based indexes and CreateIndex operation #6726

akki commented Jun 5, 2016

akki Jun 6, 2016

mjtamlyn Jun 6, 2016

akki Jun 7, 2016 •

edited

MarkusH Jun 8, 2016

mjtamlyn commented Jun 6, 2016

timgraham commented Jun 8, 2016

timgraham Jun 8, 2016

charettes commented Jun 8, 2016

MarkusH commented Jun 8, 2016 •

edited

MarkusH Jun 8, 2016

MarkusH commented Jun 8, 2016

charettes commented Jun 8, 2016

MarkusH Jun 8, 2016

akki commented Jun 19, 2016 •

edited

timgraham Jun 20, 2016

timgraham commented Jun 20, 2016

akki commented Jun 22, 2016

timgraham Jun 22, 2016

akki Jun 22, 2016

akki Jun 22, 2016

akki commented Jun 27, 2016

timgraham commented Jun 27, 2016


		.. versionadded:: 1.11

		Creates a new index in the database table for the given model. ``model_name`` is the model's name

Fixed #26709 -- Add class based indexes and CreateIndex operation #6726

Fixed #26709 -- Add class based indexes and CreateIndex operation #6726

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akki commented Jun 5, 2016

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akki commented Jun 27, 2016

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akki commented Jun 19, 2016 •

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