ORACLE FOR THE SQL SERVER DBAKELLYN POT’VIN, SR. TECHNICAL CONSULTANT
ABOUT THE PRESENTER• Oracle and MsSQL DBA for over twelve years.• Oracle ACE• Board of Directors for RMOUG, (Rocky Mountain Oracle User Group)• Database Track Committee for ODTUG’s, (Oracle Developer Tools User Group) KSCOPE 2012• Presenting this year at RMOUG, Miracle World, (Denmark) KSCOPE, Oracle User Group’s Harmony, (Finland) and other international conferences.• Resides in Broomfield, CO.• Honing skills at Enkitec, a Platinum Oracle Partner out of Dallas, Tx.
“...GET NO RESPECT…”• Oracle in comparison to SQL Server DBA’s in the technical arena.• Rarely do Oracle DBA’s have other technical groups performing their tasks.• Microsoft pushes the database platform for it’s “ease of management.”• “We won’t need your SQL Server skills, no [mission critical] MsSQL databases here…”• Only one position has kept that deal.
DIVERGENCE• Oracle Marketshare?• Oracle’s Latest Innovations?• SQL Server’s Marketshare?• SQL Server’s Latest Innovations?• MySQL in the mix…
MULTI-PLATFORM“A database is a database…”• Must be able to adapt quickly.• Must be open-minded.• Must like challenges.• Must be able to absorb a lot of information and keep it well organized mentally.• Must be open to finding the right platform/product for the task/project.
WHAT IS THE SAME• Both ACID Compliant, (atomicity, consistency, isolation, durability).• Extensive tuning options in both databases.• OLTP and DSS/Warehouse features.• Multiple Backup and Recovery level features.• High Availability and stand-by• Fully auditable, accountable and transactional level recoverable.
VERY DIFFERENT• System Databases and Temp Database- None in Oracle.• Oracle contains a SYSTEM schema, along with other schemas that house important information vs. having in separate database, i.e. SQL Server’s System tablespaces.• Temporary work is all performed in the TEMP tablespace for Oracle, which does possess physical files underneath, but no separate database.• SQL Server’s transaction log and temp database handles processing a bit differently than Oracle’s temp tablespace, redo and undo.
THE INSTANCE• INSTANCE • Oracle- The core services, (i.e. memory structure and background processes) that identifies the database. It is not the database, but again, the background processes, controlfiles and configuration, (initialization parameter file) that will be used by the database. One instance per database, unless a RAC, (Real Application Cluster.) • SQL Server- An Instance allows more than one copy of the SQL Server software to run at one time, each copy, also known as an instance. This allows the DBA to run multiple versions of SQL Server from one server, as well. For an Oracle DBA, we would translate this more to the term “Oracle Homes” instead of the term of “Instance”.
ORACLE INITIALIZATION PARAMETERS• “Init” parameters are required to (no)mount or open a database, either by: • Text based, “pfile” or parameter file. • Naming convention init<sid>.ora • Bit-secure version, “spfile” or secure parameter file. • Naming convention sp<sid>.ora
ORACLE REDO LOGS• Redo logs are stored in “member groups” and each file within the member group is referred to as a “member”.• Each Member Group includes information about last SCN change, if active, inactive and if archived.
ORACLE REDO LOG FILES• Files are mirrored for security reasons.• These files are REQUIRED to be moved for recovery and are archived off, (archive logs…)• Files are stored as part of groups and although .log is standard naming convention .rdo is recommended.• Can you suspect why the naming convention recommendation change?
ORACLE ARCHIVE LOGS• Once the Redo log is no longer Current, the archiver is able to archive the redo log file off for recovery purposes.• All archive logs contain a sequence, SCN change number and dates of activity included in their information stored.
ORACLE UNDO• Undo is required to “undo” or rollback changes. Either from a rollback request, timeout, failure or recovery scenario.• Automatic Undo tablespace, replaced Static, manually sized “Rollback Segments” as of Oracle 9i.• Automatic and easy to manage, (still many myths regarding this feature.
ORACLE ASMOracle’s answer to reduce redundancy and give DBA’s more controlover storage, luns, placement and performance of database files.
COOL ORACLE ENTERPRISE MANAGER FEATURESAble to historically trace back activity in Oracle to a given “snapshot intime”.Data is aggregated, but can drill down to individual sessions and pullinformation.
SQL SERVER LINKED SERVERSSelect * from loufin01.db1.dbo.table1 [GO]User logging in from linked server privileges are linksprivileges.
ORACLE DATABASE LINKSSelect * from schema.table1@dblinkname;• Can be private or public.
ORACLE GRANTS/PRIVILEGES• System, Schema and Role Grants• VPD, (replaces row level grants in Oracle.)
ORACLE SQL MONITOR, (11G) SQL IdentifierActivity Degree of Parallelism SQL Text Duration User Wait Event
ORACLE SCHEDULEROracle DBA’s Often do not use the Oracle Scheduler- Why?• Scripting gives more control, (shell, perl, etc. with Cron in Linux/Unix)• Scheduling time “inching”- Next execution based off completion time, allows execution movement.• Complicated command line syntax and dependencies.• New to 10g, previous scheduler, DBA Jobs, was less efficient.
BACKUP AND RECOVERY• Backups are performed by a Oracle supplied product RMAN, (Recovery Manager)• Extremely robust and flexible.• Supports full, incremental, archive log backups..• Can be used for duplicating, cloning and dataguard, (standby)• Can be configured through command line, scripts and the Enterprise Manager.
REVIEW & QUESTIONS• Oracle is a very robust RDBMS platform.• Differences are many, but its main goal is the same as SQL Server.• The goal to learning to be an Oracle DBA is to keep an open mind and embrace that with added features, comes added management. Thank you!