index_name_exists?

# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 155
        def index_name_exists?(table_name, index_name, default)
          table = Utils.extract_schema_qualified_name(table_name.to_s)
          index = Utils.extract_schema_qualified_name(index_name.to_s)

          select_value(            SELECT COUNT(*)            FROM pg_class t            INNER JOIN pg_index d ON t.oid = d.indrelid            INNER JOIN pg_class i ON d.indexrelid = i.oid            LEFT JOIN pg_namespace n ON n.oid = i.relnamespace            WHERE i.relkind = 'i'              AND i.relname = '#{index.identifier}'              AND t.relname = '#{table.identifier}'              AND n.nspname = #{index.schema ? "'#{index.schema}'" : 'ANY (current_schemas(false))'}, 'SCHEMA').to_i > 0
        end