Sybase 12.4.2 manual Controlling performance from the command line, Setting memory switches

CHAPTER 2 Running Adaptive Server IQ

You should adopt a set of naming conventions for your servers and databases, as well as for all other database objects, that includes a case specification. Enforcing naming conventions can prevent problems for users.

Controlling performance from the command line

Several command-line options can affect database server performance. Most of the switches described in this section control resources for operations on the IQ Store, which can have a major impact on performance. Switches that affect only the resources available for operations on the Catalog Store may have a minor impact on overall performance. If you need to specify switches that affect the Catalog Store only, see the Adaptive Server IQ Reference Manual for more information.

Performance tuning suggestions are given throughout this guide. See Chapter 12, “Managing System Resources” for a full discussion of how Adaptive Server IQ uses memory, disk, and processors, the effect of user connections on resource use, and options you can set to control resource use.

Some platform-specific tuning suggestions are presented in this guide. See also the Adaptive Server IQ Installation and Configuration Guide for your platform.

Setting memory switches

Adaptive Server IQ uses memory for a variety of purposes:

•Buffers for data read from disk to resolve queries

•Buffers for data read from disk when loading from flat files

•Overhead for managing connections, transactions, buffers, and database objects

The switches discussed below, as well as other options you can set once the server is running, determine how much memory is available for these purposes.

IQ buffer cache sizes Normally, you set the buffer cache size for the IQ main and temporary stores using the SET OPTION command to set the Main_Cache_Memory_MB and Temp_Cache_Memory_MB options. If you set IQ buffer cache sizes higher than your system will accommodate, however, Adaptive Server IQ cannot open the database.

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