Schema inconsistency introduced by apachesolr_update_7013

Actually, this may be more than just a simple typo.

New installations since update_7013 was introduced will have the wrong primary key. We have to introduce a new update that fixes the primary key.

Here's a screenshot from the Schema module's schema comparison report page:

This isn't a query speed up issue, this is to say that there's an error in the way the schema is declared which requires a correction via a new hook_update_N().

I believe the inconsistency only happens if you install a fresh copy of apachesolr, since fresh installs don't go through all of the hook_update_N() calls.

In the end, as you said, we want the apachesolr_index_entities table to have a primary key which consists of both entity_id and entity_type because it can include entities of all sorts. Currently, due to this typo (which checks for the key "other" when $type is a value, not a key)...

-    if ($type == 'other') {
+    if ($type == 'apachesolr_index_entities') {

If you freshly install the module, the apachesolr_index_entities table will only include entity_id in its primary key because that's what's declared in the schema. The above portion of the patch will realign apachesolr_index_entities to what the primary key should be.

However, anyone who's cleanly installed the module as of update_7013 will have the wrong schema, even if we just add the above typo fix. As a result, to take care of people who are in this state, we have to add a new update_7014 that fixes the primary key for that table.

+
+/**
+ * Re-apply primary key change for apachesolr_index_entities introduced in 7013.
+ */
+function apachesolr_update_7015() {
+  // Brand new installations since update_7013 have the wrong primary key.
+  db_drop_primary_key('apachesolr_index_entities');
+  db_add_primary_key('apachesolr_index_entities', array('entity_id', 'entity_type'));
+}

For those who installed the module awhile ago and went through the update process through 7013, update_7015 should have no effect at all.

Ah, here we go.

The code you referenced was added (here) on February 24th; the schema was changed (here) on February 2nd to add the dual primary key.

Apachesolr Beta16 (which is what I cleanly installed with) was released with the schema change (latter patch), but not the schema mismatch fix (former patch). We still need an update to fix the schema for those in my shoes who cleanly installed with Beta16.

Here's the patch with just the update.