General Database Properties

General information for the database, including properties in the following areas:

• General—Enter a description for the database and view the database type, the database status (whether it is loaded or not), and the minimum access level for the database.

• Calculation—Block Storage applications only

  • Aggregate Missing Values—Aggregates missing values during database calculations.

    By default, during full database calculations, Oracle Essbase does not aggregate missing (#Missing) values. When data is not loaded at parent levels, aggregating missing values may improve calculation performance. For databases for which you have Database Manager permissions, you can choose whether to aggregate missing values.

    If you never load data at parent levels, aggregating missing values may improve calculation performance. If you aggregate missing values and load data at the parent level, the parent-level values are replaced by the results of the database consolidation, even if the results are #Missing values.

  • Create Blocks on Equation—Creates a data block for certain member combinations.

    If you create blocks on equation, when you assign a non-constant value to a member combination for which no data block exists, Essbase creates a data block. Creating blocks on equation can produce a very large database.

    When you assign a constant to a member on a sparse dimension, Essbase creates a data block. Therefore, when assigning constants to sparse members (for example, "West = 5"), do not select Create Blocks on Equation.

    When assigning anything other than a constant to a sparse member, if you want blocks created, you must select Create Blocks on Equation. For example, if no data exists for Actuals, a member of the sparse Scenario dimension, you must select Create Blocks on Equation to perform the following allocation: 2002Forecast = Actuals * 1.05;

  • Two-Pass Calculation—Recalculates certain members.

    If you select Two Pass Calculation, after a default calculation, members tagged as two-pass are recalculated. The two-pass tag is effective on members of the dimension tagged as accounts and on Dynamic Calc and Dynamic Calc and Store members of any dimension.

• Data Retrieval Buffers

  • Buffer Size—Size of the retrieval buffer. Used to process and optimize retrievals from the spreadsheet add-in and from report scripts.

  • Sort Buffer Size—Size of the retrieval sort buffer

• Storage—Block Storage Applications Only

  • Current I/O Access Mode—Current access mode

  • Pending I/O Access Mode—One of these options is configured by default:

    • Buffered I/O—Uses the file system buffer cache. If Direct I/O was not specified for the Direction setting in the essbase.cfg file when the database was created, buffered I/O is the default.

    • Direct I/O—Bypasses the file system buffer cache and performs asynchronous, overlapped I/Os, providing faster response time and greater potential to optimize cache sizes. If Direct I/O is selected, Essbase attempts to use Direct I/O each time that the database is started. If Direct I/O is not available, Essbase uses Buffered I/O. Select Direct I/O to use cache memory locking or the no-wait (asynchronous) I/O provided by the operating system.

  • Data Compression—One of these options is configured by default:

    • Bitmap encoding—A bitmap is used to represent data cells. Only the bitmap, the block header, and other control information are stored on disk. Bitmap encoding is the most efficient method of compressing data. Essbase stores only non-missing values and does not compress repetitive or zero values. When the database brings a data block into the data cache, it uses the bitmap to recreate missing values and fully expands the block.

    • RLE (Run-Length Encoding)—Consecutive, repetitive values, including zeros, are compressed, and a record is kept of each repeating value and the number of times that it is repeated consecutively. RLE may be preferable if average block density is not greater than three percent or if the database includes many consecutive zero values or any consecutive, repeating value other than zero.

    • ZLIB—A data dictionary based on the data being compressed is created. Usually, when data is extremely dense, ZLIB compression provides the best compression ratio. However, under some circumstances, other compression methods may yield better results. With ZLIB compression, the storage space that is saved has little or no relationship to the number of missing cells or the number of contiguous cells of equal value.

    • No Compression—No compression of data is performed.