1 / 12

Objectivity/DB and Oracle - Comparing the Architectures

Objectivity/DB and Oracle - Comparing the Architectures . Dirk Düllmann Comparing the storage hierarchies… Confusing the Terminologies…. Federation. Database. Container. Page. Object. Objectivity/DB Storage Hierarchy. Main architectural limitations result from design choice for OID

danika
Download Presentation

Objectivity/DB and Oracle - Comparing the Architectures

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Objectivity/DB and Oracle- Comparing the Architectures Dirk Düllmann Comparing the storage hierarchies… Confusing the Terminologies…

  2. Federation Database Container Page Object Objectivity/DB Storage Hierarchy • Main architectural limitations result from design choice for OID • 64K databases • 32K containers per database • 64K logical pages per container • 64K object slots per page

  3. “Federation” Oracle Storage Hierarchy Database Table • No (or not yet known) limit on number of databases and tables • 64k partitions • practical limit expected to be lower • Tablespace can be declared offline and transported • 1022 files per tablespace • OS files or raw partitions • 64k files per instance • Is this sufficient? Partition Tablespace File Extend Block Object

  4. Federation • Objectivity:A set of many database files possibly distributed across several data serving hosts • Oracle:A set of many database instances possibly distributed across several hosts

  5. Database • Objectivity: A single operating system file, always part of a federation • Oracle: All data handled by a single server instance • many files locally accessible to one host

  6. Container/Table • Objectivity - Container: • Heterogeneous collection of persistent objects • Physical clustering: objects reside “close” to each other on disk • In practice often rather homogenous (clustering by type) • Oracle - Object Table: • “Homogeneous” collection of persistent objects • Logical collection: objects may spread many files • May become heterogeneous by “substitutability” • Ability to store a derived object in a table of it’s base class • Some similarities, but no 1-to-1 correspondence

  7. Partition • Objectivity:Autonomous part of a federation which is handled by an independent lockserver. • Oracle:Part of a larger table which typically resides on a different tablespace.

  8. Exten{t|d} • Object Databases:Set of all objects of a given class in an Object Database. • Oracle:Element of the lower level storage hierarchy (allocation granule for files)

  9. Block/Page • Objectivity- Page :Unit of disk and network I/Os • same value for whole federation • Oracle - Block:The disk I/O unit (not the unit of exchange between client and server), • may be vary between different tablespaces

  10. Client Side Cache • Objectivity: • Cache contains complete database pages • Persistent objects are located on those pages • Oracle: • Client cache contains individual objects • Persistent objects are constructed from table data (and written back) using (typically) generated conversion methods

  11. Storage Format • Objectivity: • “Native” format short, long, int, float, double • Some padding but otherwise closely related to C++ “in-memory” representation • Oracle: • Programming language independent format “Number” • Inpact on storage overhead, CPU overhead and numeric stability

  12. Summary • Architecture and in storage hierarchies are very different! • Performances and practical limits will differ as well… • IT/DB will perform detailed tests (see Marcins presentation) • Several common terms have very different meanings! • Don’t re-apply your Objectivity mental model to Oracle!

More Related