Remove dead MySQL code

None of this code can be reached any more, so it can all be removed

16 files changed, 14 insertions, 179 deletions

diff --git a/db/migrate/20180206200543_reset_events_primary_key_sequence.rb b/db/migrate/20180206200543_reset_events_primary_key_sequence.rb
index d395c5725e4..e7a18e68395 100644
--- a/db/migrate/20180206200543_reset_events_primary_key_sequence.rb
+++ b/db/migrate/20180206200543_reset_events_primary_key_sequence.rb
@@ -12,24 +12,10 @@ class ResetEventsPrimaryKeySequence < ActiveRecord::Migration[4.2]
   end
 
   def up
-    if Gitlab::Database.postgresql?
-      reset_primary_key_for_postgresql
-    else
-      reset_primary_key_for_mysql
-    end
+    reset_pk_sequence!(Event.table_name)
   end
 
   def down
     # No-op
   end
-
-  def reset_primary_key_for_postgresql
-    reset_pk_sequence!(Event.table_name)
-  end
-
-  def reset_primary_key_for_mysql
-    amount = Event.pluck('COALESCE(MAX(id), 1)').first
-
-    execute "ALTER TABLE #{Event.table_name} AUTO_INCREMENT = #{amount}"
-  end
 end
diff --git a/db/migrate/20180403035759_create_project_ci_cd_settings.rb b/db/migrate/20180403035759_create_project_ci_cd_settings.rb
index 00028689779..c630dd3c942 100644
--- a/db/migrate/20180403035759_create_project_ci_cd_settings.rb
+++ b/db/migrate/20180403035759_create_project_ci_cd_settings.rb
@@ -30,12 +30,6 @@ class CreateProjectCiCdSettings < ActiveRecord::Migration[4.2]
   end
 
   def add_foreign_key_with_retry
-    if Gitlab::Database.mysql?
-      # When using MySQL we don't support online upgrades, thus projects can't
-      # be deleted while we are running this migration.
-      return add_project_id_foreign_key
-    end
-
     # Between the initial INSERT and the addition of the foreign key some
     # projects may have been removed, leaving orphaned rows in our new settings
     # table.
diff --git a/db/migrate/20180406204716_add_limits_ci_build_trace_chunks_raw_data_for_mysql.rb b/db/migrate/20180406204716_add_limits_ci_build_trace_chunks_raw_data_for_mysql.rb
deleted file mode 100644
index 0b541e94353..00000000000
--- a/db/migrate/20180406204716_add_limits_ci_build_trace_chunks_raw_data_for_mysql.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
-require Rails.root.join('db/migrate/limits_ci_build_trace_chunks_raw_data_for_mysql')
-
-class AddLimitsCiBuildTraceChunksRawDataForMysql < ActiveRecord::Migration[4.2]
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  def up
-    LimitsCiBuildTraceChunksRawDataForMysql.new.up
-  end
-end
diff --git a/db/migrate/20180521171529_increase_mysql_text_limit_for_gpg_keys.rb b/db/migrate/20180521171529_increase_mysql_text_limit_for_gpg_keys.rb
deleted file mode 100644
index 08ce8cc3094..00000000000
--- a/db/migrate/20180521171529_increase_mysql_text_limit_for_gpg_keys.rb
+++ /dev/null
@@ -1 +0,0 @@
-require_relative 'gpg_keys_limits_to_mysql'
diff --git a/db/migrate/20180831164904_fix_prometheus_metric_query_limits.rb b/db/migrate/20180831164904_fix_prometheus_metric_query_limits.rb
deleted file mode 100644
index 80c4d11a38e..00000000000
--- a/db/migrate/20180831164904_fix_prometheus_metric_query_limits.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-# frozen_string_literal: true
-
-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
-require Rails.root.join('db/migrate/prometheus_metrics_limits_to_mysql')
-
-class FixPrometheusMetricQueryLimits < ActiveRecord::Migration[4.2]
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  def up
-    PrometheusMetricsLimitsToMysql.new.up
-  end
-
-  def down
-    # no-op
-  end
-end
diff --git a/db/migrate/20181030154446_add_missing_indexes_for_foreign_keys.rb b/db/migrate/20181030154446_add_missing_indexes_for_foreign_keys.rb
index 2b5cd45e92c..e21eb291282 100644
--- a/db/migrate/20181030154446_add_missing_indexes_for_foreign_keys.rb
+++ b/db/migrate/20181030154446_add_missing_indexes_for_foreign_keys.rb
@@ -34,10 +34,6 @@ class AddMissingIndexesForForeignKeys < ActiveRecord::Migration[4.2]
   end
 
   def down
-    # MySQL requires index for FK,
-    # thus removal of indexes does fail
-    return if Gitlab::Database.mysql?
-
     remove_concurrent_index(:application_settings, :usage_stats_set_by_user_id)
     remove_concurrent_index(:ci_pipeline_schedules, :owner_id)
     remove_concurrent_index(:ci_trigger_requests, :trigger_id)
diff --git a/db/migrate/gpg_keys_limits_to_mysql.rb b/db/migrate/gpg_keys_limits_to_mysql.rb
deleted file mode 100644
index 2cd347a0463..00000000000
--- a/db/migrate/gpg_keys_limits_to_mysql.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-class IncreaseMysqlTextLimitForGpgKeys < ActiveRecord::Migration[4.2]
-  # Set this constant to true if this migration requires downtime.
-  DOWNTIME = false
-
-  def up
-    return unless Gitlab::Database.mysql?
-
-    change_column :gpg_keys, :key, :text, limit: 16.megabytes - 1
-  end
-
-  def down
-    # no-op
-  end
-end
diff --git a/db/migrate/limits_ci_build_trace_chunks_raw_data_for_mysql.rb b/db/migrate/limits_ci_build_trace_chunks_raw_data_for_mysql.rb
deleted file mode 100644
index 92402cf387b..00000000000
--- a/db/migrate/limits_ci_build_trace_chunks_raw_data_for_mysql.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-class LimitsCiBuildTraceChunksRawDataForMysql < ActiveRecord::Migration[4.2]
-  def up
-    return unless Gitlab::Database.mysql?
-
-    # Mysql needs MEDIUMTEXT type (up to 16MB) rather than TEXT (up to 64KB)
-    # Because 'raw_data' is always capped by Ci::BuildTraceChunk::CHUNK_SIZE, which is 128KB
-    change_column :ci_build_trace_chunks, :raw_data, :binary, limit: 16.megabytes - 1 # MEDIUMTEXT
-  end
-end
diff --git a/db/migrate/limits_to_mysql.rb b/db/migrate/limits_to_mysql.rb
deleted file mode 100644
index 33cb19aff9e..00000000000
--- a/db/migrate/limits_to_mysql.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-class LimitsToMysql < ActiveRecord::Migration[4.2]
-  def up
-    return unless ActiveRecord::Base.configurations[Rails.env]['adapter'] =~ /^mysql/
-
-    change_column :snippets, :content, :text, limit: 2147483647
-    change_column :notes, :st_diff, :text, limit: 2147483647
-  end
-end
diff --git a/db/migrate/markdown_cache_limits_to_mysql.rb b/db/migrate/markdown_cache_limits_to_mysql.rb
deleted file mode 100644
index f99d500a137..00000000000
--- a/db/migrate/markdown_cache_limits_to_mysql.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-class MarkdownCacheLimitsToMysql < ActiveRecord::Migration[4.2]
-  DOWNTIME = false
-
-  def up
-    return unless Gitlab::Database.mysql?
-
-    change_column :snippets, :content_html, :text, limit: 2147483647
-  end
-
-  def down
-    # no-op
-  end
-end
diff --git a/db/migrate/merge_request_diff_file_limits_to_mysql.rb b/db/migrate/merge_request_diff_file_limits_to_mysql.rb
deleted file mode 100644
index 65dd0b5b7f7..00000000000
--- a/db/migrate/merge_request_diff_file_limits_to_mysql.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-class MergeRequestDiffFileLimitsToMysql < ActiveRecord::Migration[4.2]
-  DOWNTIME = false
-
-  def up
-    return unless Gitlab::Database.mysql?
-
-    change_column :merge_request_diff_files, :diff, :text, limit: 2147483647, default: nil
-  end
-
-  def down
-  end
-end
diff --git a/db/migrate/prometheus_metrics_limits_to_mysql.rb b/db/migrate/prometheus_metrics_limits_to_mysql.rb
deleted file mode 100644
index f7a2fcba8c2..00000000000
--- a/db/migrate/prometheus_metrics_limits_to_mysql.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-class PrometheusMetricsLimitsToMysql < ActiveRecord::Migration[4.2]
-  DOWNTIME = false
-
-  def up
-    return unless Gitlab::Database.mysql?
-
-    change_column :prometheus_metrics, :query, :text, limit: 4096, default: nil
-  end
-
-  def down
-  end
-end
diff --git a/db/post_migrate/20180409170809_populate_missing_project_ci_cd_settings.rb b/db/post_migrate/20180409170809_populate_missing_project_ci_cd_settings.rb
index 0cda3d76a3d..a400a071e07 100644
--- a/db/post_migrate/20180409170809_populate_missing_project_ci_cd_settings.rb
+++ b/db/post_migrate/20180409170809_populate_missing_project_ci_cd_settings.rb
@@ -9,10 +9,6 @@ class PopulateMissingProjectCiCdSettings < ActiveRecord::Migration[4.2]
   disable_ddl_transaction!
 
   def up
-    # MySQL does not support online upgrades, thus there can't be any missing
-    # rows.
-    return if Gitlab::Database.mysql?
-
     # Projects created after the initial migration but before the code started
     # using ProjectCiCdSetting won't have a corresponding row in
     # project_ci_cd_settings, so let's fix that.
diff --git a/db/post_migrate/20181219130552_update_project_import_visibility_level.rb b/db/post_migrate/20181219130552_update_project_import_visibility_level.rb
index 6209de88b31..bfa452578a3 100644
--- a/db/post_migrate/20181219130552_update_project_import_visibility_level.rb
+++ b/db/post_migrate/20181219130552_update_project_import_visibility_level.rb
@@ -49,7 +49,7 @@ class UpdateProjectImportVisibilityLevel < ActiveRecord::Migration[5.0]
   def update_projects_visibility(visibility)
     say_with_time("Updating project visibility to #{visibility} on #{Project::IMPORT_TYPE} imports.") do
       Project.with_group_visibility(visibility).select(:id).each_batch(of: BATCH_SIZE) do |batch, _index|
-        batch_sql = Gitlab::Database.mysql? ? batch.pluck(:id).join(', ') : batch.select(:id).to_sql
+        batch_sql = batch.select(:id).to_sql
 
         say("Updating #{batch.size} items.", true)
 
diff --git a/db/post_migrate/20190204115450_migrate_auto_dev_ops_domain_to_cluster_domain.rb b/db/post_migrate/20190204115450_migrate_auto_dev_ops_domain_to_cluster_domain.rb
index 392e64eeade..036b0b64b48 100644
--- a/db/post_migrate/20190204115450_migrate_auto_dev_ops_domain_to_cluster_domain.rb
+++ b/db/post_migrate/20190204115450_migrate_auto_dev_ops_domain_to_cluster_domain.rb
@@ -16,26 +16,6 @@ class MigrateAutoDevOpsDomainToClusterDomain < ActiveRecord::Migration[5.0]
   private
 
   def update_clusters_domain_query
-    if Gitlab::Database.mysql?
-      mysql_query
-    else
-      postgresql_query
-    end
-  end
-
-  def mysql_query
-    <<~HEREDOC
-    UPDATE clusters, project_auto_devops, cluster_projects
-    SET
-      clusters.domain = project_auto_devops.domain
-    WHERE
-      cluster_projects.cluster_id = clusters.id
-      AND project_auto_devops.project_id = cluster_projects.project_id
-      AND project_auto_devops.domain != ''
-    HEREDOC
-  end
-
-  def postgresql_query
     <<~HEREDOC
     UPDATE clusters
     SET domain = project_auto_devops.domain
diff --git a/db/post_migrate/20190404143330_add_unique_constraint_to_approvals_user_id_and_merge_request_id.rb b/db/post_migrate/20190404143330_add_unique_constraint_to_approvals_user_id_and_merge_request_id.rb
index 447f91ebc7e..dd85ebc8001 100644
--- a/db/post_migrate/20190404143330_add_unique_constraint_to_approvals_user_id_and_merge_request_id.rb
+++ b/db/post_migrate/20190404143330_add_unique_constraint_to_approvals_user_id_and_merge_request_id.rb
@@ -21,34 +21,18 @@ class AddUniqueConstraintToApprovalsUserIdAndMergeRequestId < ActiveRecord::Migr
   def remove_duplicates
     add_concurrent_index :approvals, [:user_id, :merge_request_id, :id]
 
-    if Gitlab::Database.mysql?
-      execute <<-SQL
-        DELETE FROM a
-        USING approvals AS a
-        INNER JOIN (
-          SELECT user_id, merge_request_id, MIN(id) as min_id
-          FROM approvals
-          GROUP BY user_id, merge_request_id
-          HAVING COUNT(id) > 1
-        ) as approvals_with_duplicates
-        ON approvals_with_duplicates.user_id = a.user_id
-        AND approvals_with_duplicates.merge_request_id = a.merge_request_id
-        WHERE approvals_with_duplicates.min_id <> a.id;
-      SQL
-    else
-      execute <<-SQL
-        DELETE FROM approvals
-        USING (
-          SELECT user_id, merge_request_id, MIN(id) as min_id
-          FROM approvals
-          GROUP BY user_id, merge_request_id
-          HAVING COUNT(id) > 1
-        ) as approvals_with_duplicates
-        WHERE approvals_with_duplicates.user_id = approvals.user_id
-        AND approvals_with_duplicates.merge_request_id = approvals.merge_request_id
-        AND approvals_with_duplicates.min_id <> approvals.id;
-      SQL
-    end
+    execute <<-SQL
+      DELETE FROM approvals
+      USING (
+        SELECT user_id, merge_request_id, MIN(id) as min_id
+        FROM approvals
+        GROUP BY user_id, merge_request_id
+        HAVING COUNT(id) > 1
+      ) as approvals_with_duplicates
+      WHERE approvals_with_duplicates.user_id = approvals.user_id
+      AND approvals_with_duplicates.merge_request_id = approvals.merge_request_id
+      AND approvals_with_duplicates.min_id <> approvals.id;
+    SQL
 
     remove_concurrent_index :approvals, [:user_id, :merge_request_id, :id]
   end