30.4.3 sys Schema Views

30.4.3 sys Schema Views

30.4.3.1 The host_summary and x$host_summary Views
30.4.3.2 The host_summary_by_file_io and x$host_summary_by_file_io Views
30.4.3.3 The host_summary_by_file_io_type and x$host_summary_by_file_io_type Views
30.4.3.4 The host_summary_by_stages and x$host_summary_by_stages Views
30.4.3.5 The host_summary_by_statement_latency and x$host_summary_by_statement_latency Views
30.4.3.6 The host_summary_by_statement_type and x$host_summary_by_statement_type Views
30.4.3.7 The innodb_buffer_stats_by_schema and x$innodb_buffer_stats_by_schema Views
30.4.3.8 The innodb_buffer_stats_by_table and x$innodb_buffer_stats_by_table Views
30.4.3.9 The innodb_lock_waits and x$innodb_lock_waits Views
30.4.3.10 The io_by_thread_by_latency and x$io_by_thread_by_latency Views
30.4.3.11 The io_global_by_file_by_bytes and x$io_global_by_file_by_bytes Views
30.4.3.12 The io_global_by_file_by_latency and x$io_global_by_file_by_latency Views
30.4.3.13 The io_global_by_wait_by_bytes and x$io_global_by_wait_by_bytes Views
30.4.3.14 The io_global_by_wait_by_latency and x$io_global_by_wait_by_latency Views
30.4.3.15 The latest_file_io and x$latest_file_io Views
30.4.3.16 The memory_by_host_by_current_bytes and x$memory_by_host_by_current_bytes Views
30.4.3.17 The memory_by_thread_by_current_bytes and x$memory_by_thread_by_current_bytes Views
30.4.3.18 The memory_by_user_by_current_bytes and x$memory_by_user_by_current_bytes Views
30.4.3.19 The memory_global_by_current_bytes and x$memory_global_by_current_bytes Views
30.4.3.20 The memory_global_total and x$memory_global_total Views
30.4.3.21 The metrics View
30.4.3.22 The processlist and x$processlist Views
30.4.3.23 The ps_check_lost_instrumentation View
30.4.3.24 The schema_auto_increment_columns View
30.4.3.25 The schema_index_statistics and x$schema_index_statistics Views
30.4.3.26 The schema_object_overview View
30.4.3.27 The schema_redundant_indexes and x$schema_flattened_keys Views
30.4.3.28 The schema_table_lock_waits and x$schema_table_lock_waits Views
30.4.3.29 The schema_table_statistics and x$schema_table_statistics Views
30.4.3.30 The schema_table_statistics_with_buffer and x$schema_table_statistics_with_buffer Views
30.4.3.31 The schema_tables_with_full_table_scans and x$schema_tables_with_full_table_scans Views
30.4.3.32 The schema_unused_indexes View
30.4.3.33 The session and x$session Views
30.4.3.34 The session_ssl_status View
30.4.3.35 The statement_analysis and x$statement_analysis Views
30.4.3.36 The statements_with_errors_or_warnings and x$statements_with_errors_or_warnings Views
30.4.3.37 The statements_with_full_table_scans and x$statements_with_full_table_scans Views
30.4.3.38 The statements_with_runtimes_in_95th_percentile and x$statements_with_runtimes_in_95th_percentile Views
30.4.3.39 The statements_with_sorting and x$statements_with_sorting Views
30.4.3.40 The statements_with_temp_tables and x$statements_with_temp_tables Views
30.4.3.41 The user_summary and x$user_summary Views
30.4.3.42 The user_summary_by_file_io and x$user_summary_by_file_io Views
30.4.3.43 The user_summary_by_file_io_type and x$user_summary_by_file_io_type Views
30.4.3.44 The user_summary_by_stages and x$user_summary_by_stages Views
30.4.3.45 The user_summary_by_statement_latency and x$user_summary_by_statement_latency Views
30.4.3.46 The user_summary_by_statement_type and x$user_summary_by_statement_type Views
30.4.3.47 The version View
30.4.3.48 The wait_classes_global_by_avg_latency and x$wait_classes_global_by_avg_latency Views
30.4.3.49 The wait_classes_global_by_latency and x$wait_classes_global_by_latency Views
30.4.3.50 The waits_by_host_by_latency and x$waits_by_host_by_latency Views
30.4.3.51 The waits_by_user_by_latency and x$waits_by_user_by_latency Views
30.4.3.52 The waits_global_by_latency and x$waits_global_by_latency Views

다음 섹션들은 sys 스키마 뷰들을 설명합니다.

sys 스키마에는 Performance Schema 테이블들을 여러 가지 방식으로 요약하는 많은 뷰가 들어 있습니다. 이들 뷰의 대부분은 쌍으로 존재하며, 쌍을 이루는 뷰 중 한쪽의 이름은 다른 쪽의 이름에 x$ 접두사가 붙은 형태입니다.

예를 들어, host_summary_by_file_io 뷰는 호스트별로 그룹화된 파일 I/O를 요약하고, 지연 시간(latency)을 피코초 단위에서 더 읽기 쉬운 값(단위 포함)으로 변환하여 표시합니다:

1mysql> SELECT * FROM sys.host_summary_by_file_io;
2+------------+-------+------------+
3| host       | ios   | io_latency |
4+------------+-------+------------+
5| localhost  | 67570 | 5.38 s     |
6| background |  3468 | 4.18 s     |
7+------------+-------+------------+

x$host_summary_by_file_io 뷰는 같은 데이터를 요약하지만, 형식화되지 않은 피코초 지연 시간을 표시합니다:

1mysql> SELECT * FROM sys.x$host_summary_by_file_io;
2+------------+-------+---------------+
3| host       | ios   | io_latency    |
4+------------+-------+---------------+
5| localhost  | 67574 | 5380678125144 |
6| background |  3474 | 4758696829416 |
7+------------+-------+---------------+

x$ 접두사가 없는 뷰는 보다 사용자 친화적이고 읽기 쉬운 출력 제공을 목적으로 합니다. 같은 값을 원시(raw) 형태로 표시하는 x$ 접두사가 있는 뷰는 데이터에 자체적인 처리를 수행하는 다른 도구에서 사용할 용도에 더 적합합니다.

x$ 접두사가 없는 뷰는 해당하는 x$ 뷰와 다음과 같은 방식으로 다릅니다:

• 바이트 개수는 format_bytes()를 사용하여 크기 단위와 함께 형식화됩니다.

• 시간 값은 format_time()을 사용하여 시간 단위와 함께 형식화됩니다.

• SQL 문장은 최대 표시 너비까지 잘리며, 이를 위해 format_statement()가 사용됩니다.

• 경로 이름은 format_path()를 사용하여 짧게 줄여집니다.