Performance impact in Oracle 8i - BLOB vs BFILE

Question

Hi Guys,
We are evaluting intermedia to store multimedia objects.
Does any know if storing and retreiving documents in Oracle database has impact on standard data stored in the database?
Is it worth having a seperate database instance for storing tables with intermedia objects?
Pal

Answer 1

Part 2:
Example 1: Let us estimate the storage requirements for a data set consisting of 500 video clips comprising a total size of 250MB (average size 512K bytes). Assume a LOB chunk size of 32768 bytes. Our model estimates that we need (8000 * 32) bytes or 250 k bytes for the index and 266 MB to hold the media data. Since the original media size is 250 MB, this represents about a 6.5% storage overhead for storing the media data in the database. The following table definition could be used to store this amount of data.
create table video_items
video_id number ,
video_clip ordsys.ordvideo
-- storage parameters for table in general
tablespace video1 storage (initial 1M next 10M )
-- special storage parameters for the video content
lob (video_clip.source.localdata) store as
(tablespace video2 storage (initial 260k next 270M )
disable storage in row nocache nologging chunk 32768);
Example 2: Let us estimate the storage requirements for a data set consisting of 5000 images with an average size of 56K bytes. The total amount of media data is 274 MB. Since the average image size is smaller, it is more space efficient to choose a smaller chunk size, say 8K, to store the data in the lob. Our model estimates that we will need about 313 MB to store the data and a little over 1 MB to store the index. In this case the 40 MB of storage required beyond the raw media content size represents a 15% overhead.
Estimating retrieval costs
Performance testing has shown that Oracle can achieve equivalent and even higher throughput performance for media content retrieval than a file system. The test was configured to retrieve media data from a server system to a requesting client system. In the database case, simple C client programs used OCI with LOB read callbacks to retrieve the data from the database. For the file system case, the client program used the standard C library functions to read data from the file system. Note that in this client server configuration, files are served remotely by the file server system. In essence, we are comparing distributed file system performance with Oracle database and SQLNet performance. These tests were performed on Windows NT 4 SP5.
Although Oracle achieved higher absolute performance, the relative CPU cost per unit of throughput ranged from 1.7 to 3 times the file system cost. (For these tests, database performance ranged from 3.4 million to 9 million bytes/sec while file system performance ranged from 2.6 million bytes/sec to 7 million bytes/sec as the number of clients ranged from 1 to 5) One reason for the very high relative CPU cost at the higher end of performance is that as the 100 Mbs network approaches saturation, the system used more CPU to achieve the next increment of throughput. If we restrict ourselves to not exceeding 70% of network utilization, then the database can use up to 2.5 times as much CPU as the file system per unit of throughput.
NOTE WELL: The extra CPU cost factors pertain only to media retrieval aspect of the workload. They do not apply to the entire system workload. See example.
Example: A file based media asset system uses 10% of a single CPU simply to serve media data to requesting clients. If we were to store the media in an Oracle database and retrieve content from the database then we could expect to need 20-25% of a single CPU to serve content at the same throughput rate.