Class: Gitlab::Database::Reindexing::ReindexConcurrently

Inherits:
Object
  • Object
show all
Defined in:
lib/gitlab/database/reindexing/reindex_concurrently.rb

Overview

This is a >= PG12 reindexing strategy based on ‘REINDEX CONCURRENTLY`

Constant Summary collapse

ReindexError = 
Class.new(StandardError)
TEMPORARY_INDEX_PATTERN = 
'\_ccnew[0-9]*'
STATEMENT_TIMEOUT = 
24.hours
PG_MAX_INDEX_NAME_LENGTH = 
63

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(index, logger: Gitlab::AppLogger) ⇒ ReindexConcurrently

Returns a new instance of ReindexConcurrently.



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# File 'lib/gitlab/database/reindexing/reindex_concurrently.rb', line 16

def initialize(index, logger: Gitlab::AppLogger)
  @index = index
  @logger = logger
end

Instance Attribute Details

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/gitlab/database/reindexing/reindex_concurrently.rb', line 14

def index
  @index
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/gitlab/database/reindexing/reindex_concurrently.rb', line 14

def logger
  @logger
end

Instance Method Details

#perform ⇒ Object

Raises:



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# File 'lib/gitlab/database/reindexing/reindex_concurrently.rb', line 21

def perform
  raise ReindexError, 'indexes serving an exclusion constraint are currently not supported' if index.exclusion?
  raise ReindexError, 'index is a left-over temporary index from a previous reindexing run' if /#{TEMPORARY_INDEX_PATTERN}/o.match?(index.name)

  # Expression indexes require additional statistics in `pg_statistic`:
  # select * from pg_statistic where starelid = (select oid from pg_class where relname = 'some_index');
  #
  # In PG12, this has been fixed in https://gitlab.com/postgres/postgres/-/commit/b17ff07aa3eb142d2cde2ea00e4a4e8f63686f96.
  # Discussion happened in https://www.postgresql.org/message-id/flat/CAFcNs%2BqpFPmiHd1oTXvcPdvAHicJDA9qBUSujgAhUMJyUMb%2BSA%40mail.gmail.com
  # following a GitLab.com incident that surfaced this (https://gitlab.com/gitlab-com/gl-infra/production/-/issues/2885).
  #
  # While this has been backpatched, we continue to disable expression indexes until further review.
  raise ReindexError, 'expression indexes are currently not supported' if index.expression?

  begin
    with_logging do
      set_statement_timeout do
        execute("REINDEX INDEX CONCURRENTLY #{quote_table_name(index.schema)}.#{quote_table_name(index.name)}")
      end
    end
  ensure
    cleanup_dangling_indexes
  end
end