diff options
Diffstat (limited to 'lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb')
| -rw-r--r-- | lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb | 92 |
1 files changed, 81 insertions, 11 deletions
diff --git a/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb b/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb index f7b0306b769..6adbe046cb0 100644 --- a/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb +++ b/lib/gitlab/database/partitioning_migration_helpers/table_management_helpers.rb @@ -66,7 +66,10 @@ module Gitlab create_range_partitioned_copy(table_name, partitioned_table_name, partition_column, primary_key) create_daterange_partitions(partitioned_table_name, partition_column.name, min_date, max_date) end - create_trigger_to_sync_tables(table_name, partitioned_table_name, primary_key) + + with_lock_retries do + create_trigger_to_sync_tables(table_name, partitioned_table_name, primary_key) + end end # Clean up a partitioned copy of an existing table. First, deletes the database function and trigger that were @@ -81,13 +84,9 @@ module Gitlab assert_not_in_transaction_block(scope: ERROR_SCOPE) with_lock_retries do - trigger_name = make_sync_trigger_name(table_name) - drop_trigger(table_name, trigger_name) + drop_sync_trigger(table_name) end - function_name = make_sync_function_name(table_name) - drop_function(function_name) - partitioned_table_name = make_partitioned_table_name(table_name) drop_table(partitioned_table_name) end @@ -177,6 +176,52 @@ module Gitlab end end + # Replaces a non-partitioned table with its partitioned copy. This is the final step in a partitioning + # migration, which makes the partitioned table ready for use by the application. The partitioned copy should be + # replaced with the original table in such a way that it appears seamless to any database clients. The replaced + # table will be renamed to "#{replaced_table}_archived" + # + # **NOTE** This method should only be used after all other migration steps have completed successfully. + # There are several limitations to this method that MUST be handled before, or during, the swap migration: + # + # - Secondary indexes and foreign keys are not automatically recreated on the partitioned table. + # - Some types of constraints (UNIQUE and EXCLUDE) which rely on indexes, will not automatically be recreated + # on the partitioned table, since the underlying index will not be present. + # - Foreign keys referencing the original non-partitioned table, would also need to be updated to reference the + # partitioned table, but unfortunately this is not supported in PG11. + # - Views referencing the original table will not be automatically updated to reference the partitioned table. + # + # Example: + # + # replace_with_partitioned_table :audit_events + # + def replace_with_partitioned_table(table_name) + assert_table_is_allowed(table_name) + + partitioned_table_name = make_partitioned_table_name(table_name) + archived_table_name = make_archived_table_name(table_name) + primary_key_name = connection.primary_key(table_name) + + replace_table(table_name, partitioned_table_name, archived_table_name, primary_key_name) + end + + # Rolls back a migration that replaced a non-partitioned table with its partitioned copy. This can be used to + # restore the original non-partitioned table in the event of an unexpected issue. + # + # Example: + # + # rollback_replace_with_partitioned_table :audit_events + # + def rollback_replace_with_partitioned_table(table_name) + assert_table_is_allowed(table_name) + + partitioned_table_name = make_partitioned_table_name(table_name) + archived_table_name = make_archived_table_name(table_name) + primary_key_name = connection.primary_key(archived_table_name) + + replace_table(table_name, archived_table_name, partitioned_table_name, primary_key_name) + end + private def assert_table_is_allowed(table_name) @@ -190,6 +235,10 @@ module Gitlab tmp_table_name("#{table}_part") end + def make_archived_table_name(table) + "#{table}_archived" + end + def make_sync_function_name(table) object_name(table, 'table_sync_function') end @@ -270,12 +319,18 @@ module Gitlab function_name = make_sync_function_name(source_table_name) trigger_name = make_sync_trigger_name(source_table_name) - with_lock_retries do - create_sync_function(function_name, partitioned_table_name, unique_key) - create_comment('FUNCTION', function_name, "Partitioning migration: table sync for #{source_table_name} table") + create_sync_function(function_name, partitioned_table_name, unique_key) + create_comment('FUNCTION', function_name, "Partitioning migration: table sync for #{source_table_name} table") - create_sync_trigger(source_table_name, trigger_name, function_name) - end + create_sync_trigger(source_table_name, trigger_name, function_name) + end + + def drop_sync_trigger(source_table_name) + trigger_name = make_sync_trigger_name(source_table_name) + drop_trigger(source_table_name, trigger_name) + + function_name = make_sync_function_name(source_table_name) + drop_function(function_name) end def create_sync_function(name, partitioned_table_name, unique_key) @@ -358,6 +413,21 @@ module Gitlab end end end + + def replace_table(original_table_name, replacement_table_name, replaced_table_name, primary_key_name) + replace_table = Gitlab::Database::Partitioning::ReplaceTable.new(original_table_name, + replacement_table_name, replaced_table_name, primary_key_name) + + with_lock_retries do + drop_sync_trigger(original_table_name) + + replace_table.perform do |sql| + say("replace_table(\"#{sql}\")") + end + + create_trigger_to_sync_tables(original_table_name, replaced_table_name, primary_key_name) + end + end end end end |