Compaq ProLiant 1000 Configuration and Tuning of Sybase System 11 for NetWare - Page 24

Page 20 Configuration and Tuning of Sybase System 11 for NetWare on Compaq Servers It is possible to configure the parameters such that you cannot start SQL Server. If this happens, you can use a normal text file editor like Novell Edit to access the sys:\servername.cfg file and set the offending parameter to a more appropriate value. sp_configure command The sp_configure command sets the values for the Sybase SQL Server tunable parameters. Some sp_configure values take effect dynamically as you change them. Others require you to stop and restart SQL Server to take effect. Use ISQL to ensure that the sp_configure run_value and config_value of the items you changed match before permitting additional users onto the system. total memory The value for total memory determines the number of Sybase pages that Sybase SQL Server allocates at startup from NetWare. One Sybase page is equal to 2KB. NetWare memory buffers are 4KB in size. Therefore it takes 2 Sybase pages to equal one NetWare memory buffer. To convert Sybase pages to MB simply divide the number of pages by 512. To convert Sybase pages to NetWare memory buffers simply divide the number of pages by 2. You should set this value such that there are al least 10% free buffers on a dedicated server and 20% free buffers on a nondedicated server. The percentage of free buffers is determined by the following method: (total cache buffers / original cache buffers) * 100 The values for total cache buffers and original cache buffers are reported by the NetWare Monitor utility on the General Information screen. The percentage of free cache buffers is also reported on the Resource Utilization screen. procedure cache percent The value for procedure cache is expressed as a percentage of the memory that is used for storing and executing Sybase stored procedures. Refer to the Memory Tuning section of this document for information on sizing the procedure cache. number of devices The value for devices simply determines the maximum number of Sybase devices allowed. Each device requires approximately 512 bytes of memory. The memory required for the default setting of 10 devices is already included in the initial requirement as recommended by Sybase. If you increase the number of devices beyond 10 you will also have to increase your initial memory estimate. number of user connections The number of user connections can greatly impact the amount of memory required by Sybase SQL Server. Each user connection requires a minimum of 51KB. This allocation can be effected by changing the values for default packet size and user stack size. Refer to the discussion of these topics in this section. recovery interval in minutes The recovery interval determines how often the server should do a checkpoint. During a checkpoint, the SQL Servers data cache area is forcibly written to disk, during which time all other database activity is suspended. Immediately after a checkpoint, user response times are slightly faster than normal until the data cache area becomes filled. Once the data cache area fills, user response times slow down to "normal" levels because of the necessary disk access and memory management. Leave the recovery interval setting at its default value unless you are willing to take the risk of setting it to a higher value. If you set the recovery interval too long, the user response times © 1996 Compaq Computer Corporation, All Rights Reserved Doc No 140A/0896