Commit 1362d9fe authored by Andreas Brandl's avatar Andreas Brandl

Shortcut concurrent index creation/removal if no effect.

Index creation does not have an effect if the index is present already.
Index removal does not have an affect if the index is not present.

This helps to avoid patterns like this in migrations:
```
if index_exists?(...)
  remove_concurrent_index(...)
end
```
parent 35097c19
...@@ -136,11 +136,14 @@ class MyMigration < ActiveRecord::Migration ...@@ -136,11 +136,14 @@ class MyMigration < ActiveRecord::Migration
disable_ddl_transaction! disable_ddl_transaction!
def up def up
remove_concurrent_index :table_name, :column_name if index_exists?(:table_name, :column_name) remove_concurrent_index :table_name, :column_name
end end
end end
``` ```
Note that it is not necessary to check if the index exists prior to
removing it.
## Adding indexes ## Adding indexes
If you need to add a unique index please keep in mind there is the possibility If you need to add a unique index please keep in mind there is the possibility
......
...@@ -59,6 +59,11 @@ module Gitlab ...@@ -59,6 +59,11 @@ module Gitlab
disable_statement_timeout disable_statement_timeout
end end
if index_exists?(table_name, column_name, options)
Rails.logger.warn "Index not created because it already exists (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}"
return
end
add_index(table_name, column_name, options) add_index(table_name, column_name, options)
end end
...@@ -83,6 +88,11 @@ module Gitlab ...@@ -83,6 +88,11 @@ module Gitlab
disable_statement_timeout disable_statement_timeout
end end
unless index_exists?(table_name, column_name, options)
Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}"
return
end
remove_index(table_name, options.merge({ column: column_name })) remove_index(table_name, options.merge({ column: column_name }))
end end
...@@ -107,6 +117,11 @@ module Gitlab ...@@ -107,6 +117,11 @@ module Gitlab
disable_statement_timeout disable_statement_timeout
end end
unless index_exists_by_name?(table_name, index_name)
Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, index_name: #{index_name}"
return
end
remove_index(table_name, options.merge({ name: index_name })) remove_index(table_name, options.merge({ name: index_name }))
end end
......
...@@ -67,17 +67,35 @@ describe Gitlab::Database::MigrationHelpers do ...@@ -67,17 +67,35 @@ describe Gitlab::Database::MigrationHelpers do
model.add_concurrent_index(:users, :foo, unique: true) model.add_concurrent_index(:users, :foo, unique: true)
end end
it 'does nothing if the index exists already' do
expect(model).to receive(:index_exists?)
.with(:users, :foo, { algorithm: :concurrently, unique: true }).and_return(true)
expect(model).not_to receive(:add_index)
model.add_concurrent_index(:users, :foo, unique: true)
end
end end
context 'using MySQL' do context 'using MySQL' do
it 'creates a regular index' do before do
expect(Gitlab::Database).to receive(:postgresql?).and_return(false) allow(Gitlab::Database).to receive(:postgresql?).and_return(false)
end
it 'creates a regular index' do
expect(model).to receive(:add_index) expect(model).to receive(:add_index)
.with(:users, :foo, {}) .with(:users, :foo, {})
model.add_concurrent_index(:users, :foo) model.add_concurrent_index(:users, :foo)
end end
it 'does nothing if the index exists already' do
expect(model).to receive(:index_exists?)
.with(:users, :foo, { unique: true }).and_return(true)
expect(model).not_to receive(:add_index)
model.add_concurrent_index(:users, :foo, unique: true)
end
end end
end end
...@@ -95,6 +113,7 @@ describe Gitlab::Database::MigrationHelpers do ...@@ -95,6 +113,7 @@ describe Gitlab::Database::MigrationHelpers do
context 'outside a transaction' do context 'outside a transaction' do
before do before do
allow(model).to receive(:transaction_open?).and_return(false) allow(model).to receive(:transaction_open?).and_return(false)
allow(model).to receive(:index_exists?).and_return(true)
end end
context 'using PostgreSQL' do context 'using PostgreSQL' do
...@@ -103,19 +122,42 @@ describe Gitlab::Database::MigrationHelpers do ...@@ -103,19 +122,42 @@ describe Gitlab::Database::MigrationHelpers do
allow(model).to receive(:disable_statement_timeout) allow(model).to receive(:disable_statement_timeout)
end end
it 'removes the index concurrently by column name' do describe 'by column name' do
it 'removes the index concurrently' do
expect(model).to receive(:remove_index) expect(model).to receive(:remove_index)
.with(:users, { algorithm: :concurrently, column: :foo }) .with(:users, { algorithm: :concurrently, column: :foo })
model.remove_concurrent_index(:users, :foo) model.remove_concurrent_index(:users, :foo)
end end
it 'does nothing if the index does not exist' do
expect(model).to receive(:index_exists?)
.with(:users, :foo, { algorithm: :concurrently, unique: true }).and_return(false)
expect(model).not_to receive(:remove_index)
model.remove_concurrent_index(:users, :foo, unique: true)
end
end
describe 'by index name' do
before do
allow(model).to receive(:index_exists_by_name?).with(:users, "index_x_by_y").and_return(true)
end
it 'removes the index concurrently by index name' do it 'removes the index concurrently by index name' do
expect(model).to receive(:remove_index) expect(model).to receive(:remove_index)
.with(:users, { algorithm: :concurrently, name: "index_x_by_y" }) .with(:users, { algorithm: :concurrently, name: "index_x_by_y" })
model.remove_concurrent_index_by_name(:users, "index_x_by_y") model.remove_concurrent_index_by_name(:users, "index_x_by_y")
end end
it 'does nothing if the index does not exist' do
expect(model).to receive(:index_exists_by_name?).with(:users, "index_x_by_y").and_return(false)
expect(model).not_to receive(:remove_index)
model.remove_concurrent_index_by_name(:users, "index_x_by_y")
end
end
end end
context 'using MySQL' do context 'using MySQL' do
......
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