Author: biju.thomas

  • Oracle Tidbits – September 2018 #oratidbit

    Oracle Tidbits – September 2018 #oratidbit

    Oracle *daily* TidBits” (#oratidbit) published on  FacebookTwitter, and Google+ during weekdays in September 2018. Hope you find these helpful to learn something new or to remind you of its existence and use.

    #oratidbit #license SQL Plan Management in Standard Edition- Only one SQL plan baseline per SQL statement is allowed and SQL plan evolution is disabled.
    #oratidbit #license Oracle Sharding – no limit on the number of either primary shards or standby shards if every shard has an Oracle Active Data Guard, Golden Gate, or Oracle RAC license. Without these, use is limited to three primary shards.
    #oratidbit #license Tablespace encryption is not available on Standard Edition (SE2) on-prem, but is included in the DBCS-SE (Oracle Database Cloud Service Standard Edition) offering.
    #oratidbit Oracle Personal Edition includes all of the components that are included with Enterprise Edition, as well as all Oracle Database options except Oracle RAC. Oracle management packs cannot be used with Personal Edition.
    #oratidbit You can enable or disable a CBO related bug fix using the _FIX_CONTROL parameter – gives granular control over specific features and bug fixes. Use V$SYSTEM_FIX_CONTROL to see what bug fix is implemented and detail.
    #oratidbit The CDB_* views can be queried only by users with the SYSDBA system privilege or SELECT ANY DICTIONARY privilege, or SELECT_CATALOG_ROLE role, or by users with direct privileges granted to them.
    #oratidbit CDB_* views include these hidden columns: CON$NAME: the name of the container whose data a given CDB_* row represents. CDB$NAME: the name of the CDB whose data a given CDB_* row represents.
    #oratidbit The AWR_ROOT_* views show the AWR data stored only on a CDB root. In general, the AWR_ROOT views are equivalent to the DBA_HIST views.
    #oratidbit A connection storm is a race condition in which application servers initiate an increasing number of connection requests, but the database server CPU is unable to schedule them immediately, which causes the application servers to create more connections.
    #oratidbit Database Resident Connection Pool (DRCP) provides a connection pool in the database server for typical web application usage scenarios where the application acquires a database connection, works on the database for a relatively short time, and then releases the connection.
    #oratidbit Database Resident Connection Pool (DRCP) is installed by default, but the DBA must start, and configure it using the DBMS_CONNECTION_POOL package.
    #oratidbit When Database Resident Connection Pool (DRCP) is configured in a database in an Oracle RAC environment, the pool configuration is applied to each database instance. Starting or stopping the pool on one instance starts or stops the pool on all instances.
    #oratidbit The Memoptimize Pool optimizes the read operation for select statements. Memoptimize Rowstore performs high-performance reads for tables specified with the MEMOPTIMIZE FOR READ clause.
    #oratidbit DBCA (Database Configuartion Assistant) enables you to create and duplicate CDBs, and create, clone, plug in, and unplug PDBs.
    #oratidbit #OEM13c You can upgrade only 13c Release 2 (13.2.0.0), 13c Release 1 (13.1.0.0), or 12c Release 5 (12.1.0.5) directly to 13c Release 3 (13.3.0.0).
    #oratidbit Oracle Data Mining supports both supervised and unsupervised data mining. The DBMS_DATA_MINING package is the application programming interface for creating, evaluating, and querying data mining models.
    #oratidbit A transformation is a SQL expression that modifies the data in one or more columns. The DBMS_DATA_MINING_TRANSFORM package implements a set of transformations that are commonly used in data mining.
    #oratidbit Oracle R Enterprise is a component of the Oracle Advanced Analytics Option of Oracle Database Enterprise Edition. Oracle R Enterprise is comprehensive, database-centric environment for end-to-end analytical processes in R.
  • Create Oracle Database 18c on Windows – Advanced Configuration for the pros

    Create Oracle Database 18c on Windows – Advanced Configuration for the pros

    Oracle Database 18c (18.3) is available for download for windows platform since August 22, 2018. If you are new to Oracle or if you are a developer and need a database to play with, you can install an Oracle 18c database quickly on your laptop with a few clicks. Read “Oracle18c Database on your Windows laptop in 6 clicks!“. If you installed the Oracle Database 18c software, and want to create a new database swiftly, read “Create Oracle Database 18c in 3 clicks!

    If you are setting up a production system or a database for enterprise applications, you will need to go through the advanced configuration. The best option is to choose “Set Up Software Only” in Oracle Universal Installer (OUI) to complete the Oracle software installation, then use Database Configuration Assistant (DBCA) to create a new database.

    OUI and DBCA have the advanced configuration. The OUI advanced configuration is not “advanced” enough, DBCA lets you customize the database configuration options even more – good for an experienced DBA. In my opinion, Oracle should remove the “Advanced Configuration” option from OUI, thus make DBAs to force use DBCA. Let’s see the “Advanced” options difference when using the OUI to create the database vs using DBCA to create the database.

    Installation Type (OUI & DBCA)

    OUI: Choose Advanced Install
    DBCA: Choose Advanced Configuration

    Database Edition & Software Owner (OUI only)

    These screens are part of the Oracle Software install. 

    Choose if you want to install Oracle Enterprise Edition or Standard Edition 2
    Choose the Windows user who will own the Oracle binaries software installation

    Choosing Database Type

    OUI gives only two options – both options include the data files from the template. 
    No custom database option.
    DBCA has more options. In addition to the two options with templates, you can create a custom database. Also, there is option to choose Single instance, or RAC or RAC one node. 

    Database Identification

    OUI options are limited. Only 1 pluggable database creation and a CDB must have one PDB. Local undo tablespace for PDB is the default.
    In DBCA you can specify the number of PDBs required in CDB. If more than one, the PDB name becomes PDB prefix. You can also create CDB with no PDBs. Option to choose local undo tablespace or not for PDB. 

    Database Storage

    OUI lets you choose file system or ASM for storage.
    DBCA has more options – use of OMF, redo and control file multiplexing. 
    OUI gives option to enable recovery, which includes configuring the fast recovery area location.
    DBCA gives option to configure Fast Recovery Area including its size, and Archive log mode. 

    Configuration Options

    OUI has enough configuration options, but DBCA has a lot more. 

    • Memory: 
      • OUI: Automatic memory management and for shared memory management, you only specify the total memory, OUI allocates the PGA and SGA. 
      • DBCA: Automatic memory management, Automatic shared memory management, and Manual shared memory management options.
    • Sizing:
      • OUI: No option to change block size (8k) or the number of processes.
      • DBCA: Option to change block size if the template used is “Custom Database”. Specify processes.
    • Character Sets:
      • OUI: Option to choose database character set.
      • DBCA: In addition to database character set, choose national character set, language, and territory.
    • Connection mode:
      • OUI: No option to change – dedicated server mode. 
      • DBCA: Option to configure a dedicated server or shared server mode. 
    • Sample Schema:
      • OUI and DBCA give the option to install the sample schema.

    MEMORY:

    OUI: Automatic memory management and shared memory management
    DBCA: Automatic memory management, Automatic
     shared memory management, and Manual shared memory management options.

    CHARACTER SETS:

    OUI: Option to choose database character set.
    DBCA: In addition to database character set, choose national character set, language, and territory.

    SIZING & CONNECTION MODE (DBCA ONLY):

    DBCA: Option to change block size if the template used is “Custom Database”.
    DBCA: Option to configure a dedicated server or shared server mode. 

    Management Options

    OUI: Option to configure OEM Cloud Control. Database Express is automatically configured on port 5500.
    DBCA: In addition to OEM Cloud Control configuration, option to specify port for Database Express. 

    Schema Passwords

    OUI and DBCA: Option to specify one password for admin accounts or different passwords. PDBADMIN is applicable only when PDBs are created. 
    OUI and DBCA: Option to specify one password for admin accounts or different passwords. PDBADMIN is applicable only when PDBs are created. 

    Database Creation Option – DBCA Only

    DBCA has option to save the DB create script, create a DB template and customize storage locations, as well as change initialization parameters. No such options in OUI.
    The Customize Storage option in DBCA gives flexibility to specify storage parameters. 
    DBCA gives option to configure a new listener or to register the database with an existing listener. OUI always creates a new listener and configures port 1521. 
    DBCA gives option to configure Oracle Database Vault and Oracle Label Security. No such option in OUI.

    Summary

    OUI: Summary shows only Global Setting and Database Configuration.
    DBCA: Summary shows much more.

    If you plan on creating a database using a GUI tool for enterprise applications, always use DBCA. DBCA gives more flexibility and options. If you are installing the software and want a database with basic default options, use the OUI starter database option, desktop class.  

    DBCA Database Creation Screens

    All the screens that belong to DBCA are in the gallery below. You can also see the options included with the OLTP and DW templates – both are very much similar, one difference is the parameter star_transformation_enabled=TRUE in DW template. Both DW and OLTP include the pre-created data files, so the database creation would be much faster. The custom template builds the database from scratch, thus takes longer.