DBA SLA Baseline

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What follows are common components of a Service Level Agreement (SLA) for an Oracle enterprise environment. This is what it looks like. This is what is normal for most Fortune 200, DOD, DOE and NASA Oracle database environments.

General Expectations

  • Databases are architected and backed up in a manner that can survive a disaster. The methods used are fully supported by Oracle (RMAN). The backup files (RMAN, exports, configuration etc.) are stored offsite.
  • Data is backed up so that the loss of a complete schema or any part of a schema's data can be restored online without adversely affecting other user schema.
  • Databases are architected to be scalable in a manner that allows them to handle increasing data loads and connections.
  • The database architecture uses current Oracle practices that do not inhibit performance, scalability and support.
  • Databases are architected to allow practical implementation of Oracle patchsets and routine CPU patches. Oracle databases are routinely monitored to proactively address issues and performance concerns.

Application level connection pooling is the norm. RAC and Shared Server are not practical alternatives to improper application connection programming practices.

Oracle Enterprise Database Architecture

  • The hardware which hosts the database is adequate (CPU, RAM, Disk Controllers, Disk/SAN, NIC etc.).
  • The server which hosts the database is dedicated to being an Oracle database server exclusively.
  • Both the database installation and database creation are implemented for an enterprise scale environment. This includes:
    • The database default block size is 8k. Custom tablespace block sizes used where appropriate.
    • All tablespaces are created as Locally Managed Tablespaces (LMTS).
    • All tablespaces are created using Automatic Segment-Space Management (ASSM).
    • Oracle memory (Shared Pool, Buffer Cache, Large Pool, Java Pool etc.) is managed automatically by Oracle.
    • User data is only stored in its corresponding dedicated tablespaces, i.e. not in Oracle internal tablespaces (SYSTEM, SYSAUX etc.).
    • The database uses Big File Tablespaces (BFTS) on all tablespaces 10 GB or larger (or that will need to scale to this size).
    • The database datafile layout uses a modern implementation of Oracle's OFA (Optimal Flexible Architecture).
    • Flashback has been implemented and row movement enabled on all user data tables.

Oracle Enterprise Support Methodologies

  • Daily database checks include monitoring for: errors, routine job execution status, connections, redo log switching, memory allocation, operational loads and acute capacity issues caused by unexpected growth spurts. *
  • Other routine checks include analyzing growth and performance trends.
  • RMAN backups go to disk and are routinely copied to tape. **
  • Data Pump exports are routinely performed for user data and routinely copied to tape. **
  • Maintenance of standard Oracle data structures is performed routinely (standard index rebuilds, tablespace defragmentation, resizing of redo logs etc.).
  • Maintenance of specialized Oracle components is performed routinely: Oracle Text index rebuilds, RAC failover node testing, Data Guard failover node testing, Streams failover node testing etc..
  • All of the standard Oracle tools required to maintain the database work (dbconsole etc.).
  • The DBA's skillset is up-to-date for implementing this level of support.

* Usually caused by the data owner not communicating a significant change in: the volume of data, connections or usage.
** A SA is responsible for ensuring the Oracle backup files are backed up to tape and manages tape retention to meet the customer's retention requirements.

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