set innodb_file_per_table to ON for MySQL / Galera

InnoDB uses a single file by default which can grow to be
tens/hundreds of gigabytes, and is not shrinkable even
if data is deleted from the database.

Best practices are that innodb_file_per_table is set to ON
which instead stores each database table in its own file, each of
which is also shrinkable by the InnoDB engine.

Closes-Bug: #1660722
Change-Id: I59ee53f6462a2eeddad72b1d75c77a69322d5de4

1 files changed, 20 insertions, 0 deletions

diff --git a/releasenotes/notes/innodb_file_per_table-f925b3bbf29d44ea.yaml b/releasenotes/notes/innodb_file_per_table-f925b3bbf29d44ea.yaml
new file mode 100644
index 0000000..e0b7c3c
--- /dev/null
+++ b/releasenotes/notes/innodb_file_per_table-f925b3bbf29d44ea.yaml
@@ -0,0 +1,20 @@
+---
+features:
+  - Enable innodb_file_per_table for MySQL/MariaDB databases
+upgrade:
+  - |
+    Newly created MySQL database tables will be stored in their own datafiles,
+    instead of in a single monolithic ibdata file.
+  - |
+    Existing MySQL database tables that are persisted within the monolithic
+    ibdata file will remain so unless the database is migrated as well.
+  - |
+    Migration of all current database tables out of the monolithic ibdata
+    file is possible by dumping and restoring the whole database to a new data
+    directory, however when using Galera the entire cluster must be shut
+    down and upgraded at once.
+  - |
+    Migration of individual tables to datafiles is possible using the
+    MySQL command "ALTER TABLE <databasename>.<tablename> ENGINE=InnoDB;",
+    however this will not shrink the ibdata file and also is not safe to run
+    on a running Galera cluster for large tables.