eeb13a02ba
`searchNotificationAvailable` never effectively use any indexes because: - `notified_at < $1`, where $1 is a recent timestamp, returns the majority of the table and therefore it is cheaper for PostgreSQL to use a sequential scan on the table. - there is no index for `deleted_at IS NULL`. However, when Clair has been running for long enough, the grand majority of rows (99%+) are expected to have a non-NULL `deleted_at` field. This commit adds a new index on this very field in order to fetch the remaining 1% in the blink of an eye. In other words, instead of realizing a full table scan for each `searchNotificationAvailable` query, we'll use the small branch of a new index, reducing the total cost from over 30k to a mere 150 on a Clair database that has already managed more than 1 000 000 notifications.
30 lines
960 B
Go
30 lines
960 B
Go
// Copyright 2016 clair authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package migrations
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import "github.com/remind101/migrate"
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func init() {
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RegisterMigration(migrate.Migration{
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ID: 4,
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Up: migrate.Queries([]string{
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`CREATE INDEX vulnerability_notification_deleted_at_idx ON Vulnerability_Notification (deleted_at);`,
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}),
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Down: migrate.Queries([]string{
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`DROP INDEX vulnerability_notification_deleted_at_idx;`,
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}),
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})
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}
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