tailieunhanh - Rampant TechPress Oracle Data Warehouse Management PHẦN 2

MTS, hoặc máy chủ đa luồng, thực sự là dành cho các hệ thống có một số lượng lớn người sử dụng (trên 150) và một số lượng giới hạn bộ nhớ. Phục vụ đa luồng được thiết lập bằng cách sử dụng tham số khởi tạo như sau: SHARED_POOL_SIZE - cần phải được tăng lên cho phép UGA MTS_LISTENER_ADDRESS - Thiết lập địa chỉ cho các MTS_SERVICE nghe | ROBO Books Monograph Data Warehousing and Oracle8i The major parameters for data warehouse tuning are SHARED_POOL_SIZE - Analyze how the pool is used and size accordingly SHARED_POOL_RESERVED_SIZE -- ditto SHARED_POOL_MIN_ALLOC -- ditto SORT_AREA_RETAINED_SIZE - Set to reduce memory usage by nonsorting users SORT_AREA_SIZE - Set to avoid disk sorts if possible OPTIMIZER_PERCENT_PARALLEL - Set to 100 to maximize parallel processing HASH_JOIN_ENABLED - Set to TRUE HASH_AREA_SIZE - Twice the size of SORT_AREA_SIZE HASH_MULTIBLOCK_IO_COUNT - Increase until performance dips BITMAP_MERGE_AREA - If you use bitmaps alot set to 3 megabytes COMPATIBLE - Set to highest level for your version or new features may not be available CREATE_BITMAP_AREA_SIZE - During warehouse build set as high as 12 megabytes else set to 8 megabytes. DB_BLOCK_SIZE - Set only at db creation can t be reset without rebuild set to at least 16kb. DB_BLOCK_BUFFERS - Set as high as possible but avoid swapping. DB_FILE_MULTIBLOCK_READ_COUNT - Set to make the value times DB_BLOCK_SIZE equal to or a multiple of the minimum disk read size on your platform usually 64 kb or 128 kb. DB_FILES and MAX_DATAFILES - set MAX_DATAFILES as high as allowed DB_FILES to 1024 or higher. DBWR_IO_SLAVES - Set to twice the number of CPUs or to twice the number of disks used for the major datafiles whichever is less. OPEN_CURSORS - Set to at least 400-600 PROCESSES - Set to at least 128 to 256 to start increase as needed. RESOURCE_LIMIT - If you want to use profiles set to TRUE ROLLBACK_SEGMENTS - Specify to expected DML processes divided by four Page 6 COPYRIGHT 2003 Rampant TechPress. All Rights Reserved. ROBO Books Monograph Data Warehousing and Oracle8i STAR_TRANSFORMATION_ENABLED - Set to TRUE if you are using star or snowflake schemas. In addition to internals tuning you will also need to limit the users ability to do damage by over using resources. Usually this is controlled through the use of PROFILES later we will .