The process size does not correspond directly to the actual database memory consumption, because the process size contains also non-database elements. The following aspects affect the process size:
▪ Cache size: The factory value is 32 MB. You can control the database cache size with the IndexFile.CacheSize parameter, see IndexFile section.
▪ Executable program footprint: The footprint approximately 5 MB, but as different libraries are initializes, the footprint can grow up to 10 MB (varies per platform and release).
▪ Client threads: Each client consumes a few hundred kilobytes of main memory.
▪ Dynamic memory reserved for command handling: Server allocates resources for execution plans, temporary data, and so on.
▪ Statement cache: When the server executes SQL statements, it parses and optimizes them first. This can be time consuming. The server can store the parsed and optimized statements in the virtual memory. The virtual memory allocation is called the statement cache. You can control the statement cache with ODBC and JDBC connection properties.
▪ Hash table for the transaction lookup table: The General.LockHashSize and MME.LockHashSize parameters affect the memory consumption. They define the number of elements in the lock hash table.
▪ Transaction and sort buffers
▪ Accessed tables that are buffered in the main memory
The maximum amount of virtual memory that can be allocated to the in-memory database process is controlled by the following configuration parameters in the [Srv] section of the solid.ini file, see Srv section:
The violations of the in-memory database memory and process limits are logged in the solmsg.out log file. Every time the memory limit that is defined with the ImdbMemoryLimit and ProcessMemoryLimit parameters is exceeded, a system event is posted, see SQL: System events.