ORACLE OBJECTS FOR OLE(OO4O) PERFORMANCE TUNING

Question

제품 : ORACLE SERVER
작성날짜 : 1997-10-10
ODBC의 경우는 Block단위로 data를 Query하는데 비해 OLE의 경우는 한번에 전체
의 자료를 가져다가 Temporary storage space에 넣게 됩니다.
그래서 튜닝을 위해서는
Windows 3.1의 경우는 c:/windows/oraole.ini
WIN95의 경우는 HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\OO4O
parameters를 수정해야 합니다.
만일 위의 File이 없는 경우는 모든 변수가 Default로 설정된 경우이므로 인스톨
된 Help를 자세히 읽어보고 적용을 해야합니다.
FetchLimit이 가장 큰 영향을 끼치는 파라미터로, 일반적으로 이 값이 클수록
속도가 빨라지게 됩니다. 다음은 관련 자료입니다.
Tuning and Customization
A number of working parameters of Oracle Objects for OLE can be
customized. Access to these parameters is provided through the Oracle
initialization file, by default named ORAOLE.INI.
Each entry currently available in that file is described below. The location
of the ORAOLE.INI file is specified by the ORAOLE environment variable.
Note that this variable should specify a full pathname to the Oracle
initialization file, which is not necessarily named ORAOLE.INI. If this
environment variable is not set, or does not specify a valid file entry, then
Oracle Objects for OLE looks for a file named ORAOLE.INI in the Windows
directory. If this file does not exist, all of the default values
listed will apply.
You can customize the following sections of the ORAOLE.INI file:
[Cache Parameters]
A cache consisting of temporary data files is created to manage amounts
of data too large to be maintained exclusively in memory. This cache
is needed primarily for dynaset objects, where, for example, a single
LONG RAW column can contain more data than exists in physical
(and virtual) emory.
The default values have been chosen for simple test cases, running on a machine
with limited Windows resources. Tuning with respect to your machine and
applications is recommended.
Note that the values specified below are for a single cache, and that a separate
cache is allocated for each object that requires one. For example, if
your application contains three dynaset objects, three independent data
caches are constructed, each using resources as described below.
SliceSize = 256 (default)
This entry specifies the minimum number of bytes used to store a piece
of data in the cache. Items smaller than this value are allocated the
full SliceSize bytes for storage; items larger than this value are
allocated an integral multiple of this space value. An example of an
item to be stored is a field value of a dynaset.
PerBlock = 16 (default)
This entry specifies the number of Slices (described in the preceding
entry) that are stored in a single block. A block is the minimum unit
of memory or disk allocation used within the cache. Blocks are read
from and written to the disk cache temporary file in their entirety. Assuming a SliceSize of 256 and a PerBlock value of 16, then the block
size is 256 * 16 = 4096 bytes.
CacheBlocks = 20 (default)
This entry specifies the maximum number of blocks held in memory at any
one time. As data is added to the cache, the number of used blocks
grows until the value of CacheBlocks is reached. Previous blocks are
swapped from memory to the cache temporary disk file to make room for
more blocks. The blocks are swapped based upon recent usage. The total
amount of memory used by the cache is calculated as the product of
(SliceSize * PerBlock * CacheBlocks).
Recommended Values: You may need to experiment to find optimal cache parameter
values for your applications and machine environment. Here are some guidelines
to keep in mind when selecting different values:
The larger the (SliceSize * PerBlock) value, the more disk I/O is
required for swapping individual blocks. The smaller the (SliceSize * PerBlock) value, the
more likely it is that blocks will need to be swapped to or from disk.
The larger the CacheBlocks value, the more memory is required, but the
less likely it is that Swapping will be required.
A reasonable experiment for determining optimal performance might
proceed as follows:
Keep the SliceSize >= 128 and vary PerBlock to give a range of block
sizes from 1K through 8K.
Vary the CacheBlocks value based upon available memory. Set it high
enough to avoid disk I/O, but not so high that Windows begins swapping
memory to disk.
Gradually decrease the CacheBlocks value until performance degrades or
you are satisfied with the memory usage. If performance drops off,
increase the CacheBlocks value once again as needed to restore
performance.
[Fetch Parameters]
FetchLimit = 20 (default)
This entry specifies the number of elements of the array into which data
is fetched from Oracle. If you change this value, all fetched values
are immediately placed into the cache, and all data is retrieved from
the cache. Therefore, you should create cache parameters such that all
of the data in the fetch arrays can fit into cache memory. Otherwise,
inefficiencies may result.
Increasing the FetchLimit value reduces the number of fetches (calls
to the database) calls and possibly the amount of network traffic.
However, with each fetch, more rows must be processed before user
operations can be performed. Increasing the FetchLimit increases
memory requirements as well.
FetchSize = 4096 (default)
This entry specifies the size, in bytes, of the buffer (string) used for
retrieved data. This buffer is used whenever a long or long raw column
is initially retrieved.
[General]
TempFileDirectory = [Path]
This entry provides one method for specifying disk drive and directory
location for the temporary cache files. The files are created in the
first legal directory path given by:
1.The drive and directory specified by the TMP environment variable
(this method takes precedence over all others);
2.The drive and directory specified by this entry (TempFileDirectory)
in the [general] section of the ORAOLE.INI file;
3.The drive and directory specified by the TEMP environment variable; or
4.The current working drive and directory.
HelpFile = [Path and File Name]
This entry specifies the full path (drive/path/filename) of the Oracle Objects
for OLE help file as needed by the Oracle Data Control. If this entry cannot
be located, the file ORACLEO.HLP is assumed to be in the directory where
ORADC.VBX is located
(normally \WINDOWS\SYSTEM).

Answer 1

제품 : ORACLE SERVER
작성날짜 : 1997-10-10
ODBC의 경우는 Block단위로 data를 Query하는데 비해 OLE의 경우는 한번에 전체
의 자료를 가져다가 Temporary storage space에 넣게 됩니다.
그래서 튜닝을 위해서는
Windows 3.1의 경우는 c:/windows/oraole.ini
WIN95의 경우는 HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\OO4O
parameters를 수정해야 합니다.
만일 위의 File이 없는 경우는 모든 변수가 Default로 설정된 경우이므로 인스톨
된 Help를 자세히 읽어보고 적용을 해야합니다.
FetchLimit이 가장 큰 영향을 끼치는 파라미터로, 일반적으로 이 값이 클수록
속도가 빨라지게 됩니다. 다음은 관련 자료입니다.
Tuning and Customization
A number of working parameters of Oracle Objects for OLE can be
customized. Access to these parameters is provided through the Oracle
initialization file, by default named ORAOLE.INI.
Each entry currently available in that file is described below. The location
of the ORAOLE.INI file is specified by the ORAOLE environment variable.
Note that this variable should specify a full pathname to the Oracle
initialization file, which is not necessarily named ORAOLE.INI. If this
environment variable is not set, or does not specify a valid file entry, then
Oracle Objects for OLE looks for a file named ORAOLE.INI in the Windows
directory. If this file does not exist, all of the default values
listed will apply.
You can customize the following sections of the ORAOLE.INI file:
[Cache Parameters]
A cache consisting of temporary data files is created to manage amounts
of data too large to be maintained exclusively in memory. This cache
is needed primarily for dynaset objects, where, for example, a single
LONG RAW column can contain more data than exists in physical
(and virtual) emory.
The default values have been chosen for simple test cases, running on a machine
with limited Windows resources. Tuning with respect to your machine and
applications is recommended.
Note that the values specified below are for a single cache, and that a separate
cache is allocated for each object that requires one. For example, if
your application contains three dynaset objects, three independent data
caches are constructed, each using resources as described below.
SliceSize = 256 (default)
This entry specifies the minimum number of bytes used to store a piece
of data in the cache. Items smaller than this value are allocated the
full SliceSize bytes for storage; items larger than this value are
allocated an integral multiple of this space value. An example of an
item to be stored is a field value of a dynaset.
PerBlock = 16 (default)
This entry specifies the number of Slices (described in the preceding
entry) that are stored in a single block. A block is the minimum unit
of memory or disk allocation used within the cache. Blocks are read
from and written to the disk cache temporary file in their entirety. Assuming a SliceSize of 256 and a PerBlock value of 16, then the block
size is 256 * 16 = 4096 bytes.
CacheBlocks = 20 (default)
This entry specifies the maximum number of blocks held in memory at any
one time. As data is added to the cache, the number of used blocks
grows until the value of CacheBlocks is reached. Previous blocks are
swapped from memory to the cache temporary disk file to make room for
more blocks. The blocks are swapped based upon recent usage. The total
amount of memory used by the cache is calculated as the product of
(SliceSize * PerBlock * CacheBlocks).
Recommended Values: You may need to experiment to find optimal cache parameter
values for your applications and machine environment. Here are some guidelines
to keep in mind when selecting different values:
The larger the (SliceSize * PerBlock) value, the more disk I/O is
required for swapping individual blocks. The smaller the (SliceSize * PerBlock) value, the
more likely it is that blocks will need to be swapped to or from disk.
The larger the CacheBlocks value, the more memory is required, but the
less likely it is that Swapping will be required.
A reasonable experiment for determining optimal performance might
proceed as follows:
Keep the SliceSize >= 128 and vary PerBlock to give a range of block
sizes from 1K through 8K.
Vary the CacheBlocks value based upon available memory. Set it high
enough to avoid disk I/O, but not so high that Windows begins swapping
memory to disk.
Gradually decrease the CacheBlocks value until performance degrades or
you are satisfied with the memory usage. If performance drops off,
increase the CacheBlocks value once again as needed to restore
performance.
[Fetch Parameters]
FetchLimit = 20 (default)
This entry specifies the number of elements of the array into which data
is fetched from Oracle. If you change this value, all fetched values
are immediately placed into the cache, and all data is retrieved from
the cache. Therefore, you should create cache parameters such that all
of the data in the fetch arrays can fit into cache memory. Otherwise,
inefficiencies may result.
Increasing the FetchLimit value reduces the number of fetches (calls
to the database) calls and possibly the amount of network traffic.
However, with each fetch, more rows must be processed before user
operations can be performed. Increasing the FetchLimit increases
memory requirements as well.
FetchSize = 4096 (default)
This entry specifies the size, in bytes, of the buffer (string) used for
retrieved data. This buffer is used whenever a long or long raw column
is initially retrieved.
[General]
TempFileDirectory = [Path]
This entry provides one method for specifying disk drive and directory
location for the temporary cache files. The files are created in the
first legal directory path given by:
1.The drive and directory specified by the TMP environment variable
(this method takes precedence over all others);
2.The drive and directory specified by this entry (TempFileDirectory)
in the [general] section of the ORAOLE.INI file;
3.The drive and directory specified by the TEMP environment variable; or
4.The current working drive and directory.
HelpFile = [Path and File Name]
This entry specifies the full path (drive/path/filename) of the Oracle Objects
for OLE help file as needed by the Oracle Data Control. If this entry cannot
be located, the file ORACLEO.HLP is assumed to be in the directory where
ORADC.VBX is located
(normally \WINDOWS\SYSTEM).