The information that follows is an excerpt from Oracle9i Database Performance Guide and Reference and Oracle9i Database Reference, and is presented as an overview of the topic. 11.1 Setting Database Initialization Parameters This feature enables a simple, flexible, nonintrusive, and secure mechanism for the DBA to manage access to large files in the server file system. įor guidelines on using the DIRECTORY feature in Oracle9 i, see Oracle9i Application Developer's Guide - Large Objects (LOBs). Improving interMedia LOB data retrieval and update performanceįor more information about LOB partitioning, LOB tuning, and LOB buffering, see Oracle9i Application Developer's Guide - Large Objects (LOBs), Oracle Call Interface Programmer's Guide, Oracle9i Database Concepts, and Oracle9i Database Performance Guide and Reference.įor information on restrictions to consider when using LOBs, see Oracle9i Application Developer's Guide - Large Objects (LOBs).Putting into practice user guidelines for best performance results.Improving multimedia data INSERT performance in interMedia objects containing LOBs.Issues to consider in creating tables with interMedia objects containing LOBs.Setting database initialization parameters.The following general topics will help you to better manage your interMedia LOB data: Oracle interMedia manages a variety of LOB types. BFILEs can be as large as the operating system will allow up to a maximum of 4 gigabytes. Internal LOBs consist of: CLOBs, NCLOBs, and BLOBs and can be up to 4 gigabytes in size. This chapter discusses only the management of audio, image, and video data. All these media types are typically stored in LOBs, in either internal LOBs (stored in an internal database tablespace) or in BFILEs (external LOBs in operating system files outside of the database tablespaces). Multimedia data consists of a variety of media types including character text, images, audio clips, video clips, line drawings, and so forth. Because application development and design decisions have the greatest effect on performance, standard tuning methods must be applied to the system planning, design, and development phases of the project to achieve optimal results for your interMedia application in a production environment. The goals of your interMedia application determine the resource needs and how those resources should be allocated. However, the benefit from deduplication small files is limited so I think the default average chunk size of 4MB is a reasonable choice.įor photos or documents like Microsoft word files, I don't think there is any deduplication between version to exploit, since a small edit will render a completely different file from beginning to end.This chapter provides tuning tips for the Oracle DBA who wants to achieve more efficient storage and management of multimedia data in the database when using Oracle interMedia. So if you frequently edit text files that are about a few hundred kilobytes you may want to consider a smaller chunk size. Any file smaller than the average chunk size is unlikely to see deduplication between different versions. The average chunk size also determines the deduplication efficiency. So the larger the chunk, the less overhead there is. Duplicacy performs 2 API calls for each new chunk, one for checking the existence and the other for actually uploading the chunk. The default average chunk size of 4MB is set so mostly because of performance concern. It would be convenient to have hints available in the documentation. All these parameters have impact on the optimal chunk size. How to choose the "best" value for the chunk size parameters ?Įg: count of files in the repository, average file size size, file kind ( jpeg, raw, documents.), Size of storage.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |