Book query optimizations

server/migrations/changelog.md

@@ -12,3 +12,4 @@ Please add a record of every database migration that you create to this file. Th
 | v2.17.4        | v2.17.4-use-subfolder-for-oidc-redirect-uris | Save subfolder to OIDC redirect URIs to support existing installations                                        |
 | v2.17.5        | v2.17.5-remove-host-from-feed-urls           | removes the host (serverAddress) from URL columns in the feeds and feedEpisodes tables                        |
 | v2.17.6        | v2.17.6-share-add-isdownloadable             | Adds the isDownloadable column to the mediaItemShares table                                                   |
+| v2.17.7        | v2.17.7-add-indices                          | Adds indices to the libraryItems and books tables to reduce query times                                       |

server/migrations/v2.17.7-add-indices.js

@@ -0,0 +1,83 @@
+/**
+ * @typedef MigrationContext
+ * @property {import('sequelize').QueryInterface} queryInterface - a suquelize QueryInterface object.
+ * @property {import('../Logger')} logger - a Logger object.
+ *
+ * @typedef MigrationOptions
+ * @property {MigrationContext} context - an object containing the migration context.
+ */
+
+const migrationVersion = '2.17.7'
+const migrationName = `${migrationVersion}-add-indices`
+const loggerPrefix = `[${migrationVersion} migration]`
+
+/**
+ * This upward migration adds some indices to the libraryItems and books tables to improve query performance
+ *
+ * @param {MigrationOptions} options - an object containing the migration context.
+ * @returns {Promise<void>} - A promise that resolves when the migration is complete.
+ */
+async function up({ context: { queryInterface, logger } }) {
+  // Upwards migration script
+  logger.info(`${loggerPrefix} UPGRADE BEGIN: ${migrationName}`)
+
+  await addIndex(queryInterface, logger, 'libraryItems', ['libraryId', 'mediaType', 'size'])
+  await addIndex(queryInterface, logger, 'books', ['duration'])
+
+  logger.info(`${loggerPrefix} UPGRADE END: ${migrationName}`)
+}
+
+/**
+ * This downward migration script removes the indices added in the upward migration script
+ *
+ * @param {MigrationOptions} options - an object containing the migration context.
+ * @returns {Promise<void>} - A promise that resolves when the migration is complete.
+ */
+async function down({ context: { queryInterface, logger } }) {
+  // Downward migration script
+  logger.info(`${loggerPrefix} DOWNGRADE BEGIN: ${migrationName}`)
+
+  await removeIndex(queryInterface, logger, 'libraryItems', ['libraryId', 'mediaType', 'size'])
+  await removeIndex(queryInterface, logger, 'books', ['duration'])
+
+  logger.info(`${loggerPrefix} DOWNGRADE END: ${migrationName}`)
+}
+
+/**
+ * Utility function to add an index to a table. If the index already exists, it logs a message and continues.
+ *
+ * @param {import('sequelize').QueryInterface} queryInterface
+ * @param {import ('../Logger')} logger
+ * @param {string} tableName
+ * @param {string[]} columns
+ */
+async function addIndex(queryInterface, logger, tableName, columns) {
+  try {
+    logger.info(`${loggerPrefix} adding index [${columns.join(', ')}] to table "${tableName}"`)
+    await queryInterface.addIndex(tableName, columns)
+    logger.info(`${loggerPrefix} added index [${columns.join(', ')}] to table "${tableName}"`)
+  } catch (error) {
+    if (error.name === 'SequelizeDatabaseError' && error.message.includes('already exists')) {
+      logger.info(`${loggerPrefix} index [${columns.join(', ')}] for table "${tableName}" already exists`)
+    } else {
+      throw error
+    }
+  }
+}
+
+/**
+ * Utility function to remove an index from a table.
+ * Sequelize implemets it using DROP INDEX IF EXISTS, so it won't throw an error if the index doesn't exist.
+ *
+ * @param {import('sequelize').QueryInterface} queryInterface
+ * @param {import ('../Logger')} logger
+ * @param {string} tableName
+ * @param {string[]} columns
+ */
+async function removeIndex(queryInterface, logger, tableName, columns) {
+  logger.info(`${loggerPrefix} removing index [${columns.join(', ')}] from table "${tableName}"`)
+  await queryInterface.removeIndex(tableName, columns)
+  logger.info(`${loggerPrefix} removed index [${columns.join(', ')}] from table "${tableName}"`)
+}
+
+module.exports = { up, down }

server/models/Book.js

@@ -321,10 +321,10 @@ class Book extends Model {
           // },
           {
             fields: ['publishedYear']
+          },
+          {
+            fields: ['duration']
           }
-          // {
-          //   fields: ['duration']
-          // }
         ]
       }
     )

server/models/LibraryItem.js

@@ -1061,6 +1061,9 @@ class LibraryItem extends Model {
           {
             fields: ['libraryId', 'mediaType']
           },
+          {
+            fields: ['libraryId', 'mediaType', 'size']
+          },
           {
             fields: ['libraryId', 'mediaId', 'mediaType']
           },