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database: Fix view schemas in place when loading

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On restart the view schemas are loaded and might contain old
views with an unmarked computed column. We already have code to
update the schema, but before we do it we load the view as is. This
is not desired since once registered, this view version can be used
for writes which is forbidden since we will spot a none computed
column which is in the view's primary key but not in the base table
at all. To solve this, in addition to altering the persistent schema,
we fix the view's loaded schema in place. This is safe since computed
column is just involved in generating a value for this column when
creating a view update so the effect of this manipulation stays
internal.
The second stage of the in place fixing is to persist the
changes made in the in place fixing so the view is ready for
the next node restart in particular the `computed_columns` table.
This commit is contained in:
Eliran Sinvani
2021-02-22 12:55:22 +02:00
parent 04de770566
commit 0220786710
1 changed files with 16 additions and 11 deletions
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27
database.cc
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@@ -845,17 +845,22 @@ future<> database::parse_system_tables(distributed<service::storage_proxy>& prox
});
}).then([&proxy, &mm, this] {
return do_parse_schema_tables(proxy, db::schema_tables::VIEWS, [this, &proxy, &mm] (schema_result_value_type &v) {
return create_views_from_schema_partition(proxy, v.second).then([this, &mm] (std::vector<view_ptr> views) {
return parallel_for_each(views.begin(), views.end(), [this, &mm] (auto&& v) {
return this->add_column_family_and_make_directory(v).then([this, &mm, v] {
// TODO: Remove once computed columns are guaranteed to be featured in the whole cluster.
view_ptr fixed_v = maybe_fix_legacy_secondary_index_mv_schema(*this, v, nullptr, preserve_version::no);
if (fixed_v) {
return mm.local().announce_view_update(view_ptr(fixed_v));
} else {
return make_ready_future<>();
}
});
return create_views_from_schema_partition(proxy, v.second).then([this, &mm, &proxy] (std::vector<view_ptr> views) {
return parallel_for_each(views.begin(), views.end(), [this, &mm, &proxy] (auto&& v) {
// TODO: Remove once computed columns are guaranteed to be featured in the whole cluster.
// we fix here the schema in place in oreder to avoid races (write commands comming from other coordinators).
view_ptr fixed_v = maybe_fix_legacy_secondary_index_mv_schema(*this, v, nullptr, preserve_version::yes);
view_ptr v_to_add = fixed_v ? fixed_v : v;
future<> f = this->add_column_family_and_make_directory(v_to_add);
if (bool(fixed_v)) {
v_to_add = fixed_v;
auto&& keyspace = find_keyspace(v->ks_name()).metadata();
auto mutations = db::schema_tables::make_update_view_mutations(keyspace, view_ptr(v), fixed_v, api::new_timestamp(), true);
f = f.then([this, &proxy, mutations = std::move(mutations)] {
return db::schema_tables::merge_schema(proxy, _feat, std::move(mutations));
});
}
return f;
});
});
});