DATABASE ADMINISTRATIONPertemuan ke-5

Performance Management

source : Database Administrationthe complete guide to practices and procedureschapter 9by. Craig S. Mullins

performance monitoring and tuning salah satu tugas penting DBA

Komputer bagaimana mendapatkan kinerja yang baik

Kinerja DBMS memiliki reputasi yang buruk dalam hal performance

Konten materi :› Performance monitoring› Tuning› Perbedaan monitoring dan performance management

Defining Performance

Organisasi pengguna IT monitor dan tune performa IT infrastruktur

Infrastruktur IT meliputi› Server› Jaringan› Aplikasi› Database

Performance management yang digunakan masih reaktif

Contoh : tablespace yang sudah penuh

Apa database performance ? Efisiensi ? Konsep db performance konsep supply and

demand User request informasi dari db Dbms supply informasi Db performance tingkat dimana DBMS

mensupply informasi untuk permintaan users

Lima faktor yang mempengaruhi kinerja database

workload, throughput, resources, optimization, and contention

workload

Kombinasi dari transaksi online, batch jobs, adhoc query, analisa data warehousing, dan perintah sistem dalam satu waktu

Dapat fluktuatif dari hari ke hari, jam ke jam, menit ke menit

terkadang dapat diprediksi (contoh : penggunaan internet paling banyak pada waktu istirahat)

Lebih sering tidak dapat diprediksi Memiliki dampak besar pada performa db

throughput

Kemampuan seluruh komputer untuk memproses data

Gabungan kecepatan I/O, CPU dan kemampuan paralel komputer, efisiensi OS dan system software

Resource

Hardware dan software sebagai tempat untuk penampungan data sistem

Meliputi› Db kernel› Disk storage› RAM chips› Cache control› microcode

optimatizion

Semua sistem dapat dilakukan optimasi DBMS perlu optimasi khusus dilakukan ke

dalam internal DBMS Banyak faktor yang perlu dioptimalkan SQL

query, db parameter

contention

Permintaan yang tinggi muncul contention Contention kondisi dimana dua atau lebih

komponen dari kerja menggunakan sebuah resource dengan bertentangan

Contoh dua upate bersamaan pada satu data Contention naik, througput naik

Monitoring vs. Management

Butuh langkah proaktif selain langkah reaktif Perubahan pada kode aplikasi belum bisa

dianggap langkah proaktif Langkah proaktif memperbaiki masalah

sebelum menyelesaikan aplikasi Dba sering menggunakan pendekatan reaktif

Penggunaan event-drivent tools untuk mendeteksi masalah kinerja secara otomatis

Manajemen performance != monitoring performance

Manajemen performance combine monitoring performance + resolve masalah

Meliputi 3 komponen spesifik› Monitoring, analisis, dan koreksi

Monitoring identifikasi masalah

Figure 9-1. The components of performance management

analisa

Komponen kedua dari performance management Monitoring dapat menghasilkan ribuan laporan

masalah Hasil monitoring tidak dapat digunakan untuk

mengambil keputusan Analisa diperlukan untuk mencari penyebab

utama dan cara mengatasi masalah Hanya dapat dilakukan oleh tenaga ahli, seperti

DBA

Types of Performance Tuning

Aplikasi db memerlukan interkasi konstan antara beberapa resource komputer agar bekerja sesuai spesifkasinya

Tuning db dapat dipecah menjadi 3 komponen› System tuning› Db tuning› Aplikasi tuning

Ketiganya berhubungan

System Tuning

System tuning occurs at the highest level and has the greatest impact on the overall health of database applications because every application depends on the system.

For the purposes of this discussion, we will define the system as comprising the DBMS itself and all of the related components on which it relies.

No amount of tuning is going to help a database or application when the server it is running on is short on resources or improperly installed.

The DBMS can and must be tuned to assure optimum performance.

The way in which the DBMS software is installed, its memory, disk, CPU, other resources, and any configuration options can impact database application performance.

The other systems software with which the DBMS interacts includes the operating system, networking software, message queueing systems, middleware, and transaction processors.

System tuning comprises installation, configuration, and integration issues, as well as ensuring connectivity of the software to the DBMS and database applications.

Database Tuning

Performance can be impacted by the physical design of the database, including normalization, disk storage, number of tables, index design, and use of DDL and its associated parameters.

The physical location of database files on disk systems will have an impact on the performance of applications accessing the data.

As more data is stored on the same disk device, the possibility of performance degradation increases.

However, design is not the only component of database performance. The organization of the database will change over time.

As data is inserted, updated, and deleted from the database, the efficiency of the database will degrade. Moreover, the files that hold the data may need to expand as more data is added.

Perhaps additional files, or file extents, will need to be allocated. Both disorganization and file growth can degrade performance. Indexes also need to be monitored, analyzed, and tuned to

optimize data access and to ensure that they are not having a negative impact on data modification.

Application Tuning

The application itself must be designed appropriately and monitored for efficiency.

Most experts agree that as much as 75% of performance problems are caused by improperly coded applications.

SQL is the primary culprit; coding efficient SQL statements can be complicated.

Developers need to be taught how to properly formulate, monitor, and tune SQL statements.

However, not all application problems are due to improperly coded SQL. The host language application code in which the SQL has been

embedded may be causing the problem. For example, Java, COBOL, C++, or Visual Basic code may be inefficient,

causing database application performance to suffer.

Performance Tuning Tools

Tools DB efektif membantu mengatur performa DB

Beberapa vendor menyertakan beberapa tools untuk performance management

Tapi tidak terlalu bisa menangani tipe data yang sangat banyak

Tools DB dapat dikatagorikan 2 tuama› Performance management› Performance optimization

Contoh tools

Performance monitor Performance estimation Capacity planning tools SQL analysis dan tuning Advisory tools augment SQL System analysis dan tuning

DBMS Performance Basics

We have defined database performance and discussed it from a high level.

Before we delve into the specifics of system, database, and application performance, let's examine some rules of thumb for achieving your DBMS-related performance goals.

Aturan tuning

Do not over-tune Remain focused Do not panic Communicate clearly Accept reality

Summary

Applications that access relational databases are only as good as the performance they achieve.

The wise organization will implement a comprehensive performance monitoring, tuning, and management environment that consists of policies, procedures, and integrated performance management tools and utilities.

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