Some database manager and database configuration parameters now have higher
upper limits, but only for 64-bit releases. To take full
advantage of the larger address space available to 64-bit executables, you may
need to tune memory-related configuration parameters. The following
tables denote previous and current upper limits for affected database and
database manager configuration parameters.
Table 1. Memory-related Database Manager Configuration Parameters
Parameter | Previous Upper Limit | Current Upper Limit |
---|---|---|
AGENT_STACK_SZ | 1000 | same |
APPLHEAPSZ | 128 | 256 |
ASLHEAPSZ | 524288 | same |
AUDIT_BUF_SZ | 65000 | same |
BACKBUFSZ | 524288 | same |
DOS_RQRIOBLK | 65535 | same |
DRDA_HEAP_SZ | 60000 | same |
FCM_NUM_ANCHORS | 120000 | 524288 |
FCM_NUM_BUFFERS | 65300 | 524288 |
FCM_NUM_CONNECT | 120000 | 524288 |
FCM_NUM_RQB | 120000 | 524288 |
JAVA_HEAP_SZ | 4096 | same |
MIN_PRIV_MEM | 112000 | same |
MON_HEAP_SZ | 60000 | same |
PRIV_MEM_THRESH | 112000 | same |
QUERY_HEAP_SZ | 524288 | same |
RESTBUFSZ | 524288 | same |
RQIOBLK | 65535 | same |
SHEAPTHRES | 2097152 | 2147483647 |
STMTHEAP | 2048 | 4096 |
UDF_MEM_SZ | 60000 | same |
Table 2. Memory-related Database Configuration Parameters
Parameter | Previous Upper Limit | Current Upper Limit | ||
---|---|---|---|---|
APP_CTL_HEAP_SZ | 64000 | same | ||
APPLHEAPSZ | 60000 | same | ||
BUFFPAGE | 524288 | 2147483647 | ||
CATALOGCACHE_SZ | 60000 | same | ||
DBHEAP | 60000 | 524288 (for both 32-bit and 64-bit) | ||
ESTORE_SEG_SZa | 1048575 | same | ||
LOGBUFSZ | 4096 | 65535 | ||
PCKCACHESZ | 64000 | 524288 | ||
SORTHEAP | 524288 | same | ||
STAT_HEAP_SZ | 524288 | same | ||
STMTHEAP | 60000 | same | ||
UTIL_HEAP_SZ | 524288 | same | ||
|
The internal representation of the DBHEAP database configuration parameter has changed from 16 bits to 64 bits for 64-bit releases, and to 32 bits for 32-bit releases.
The old DBHEAP token (SQLF_DBTN_DBHEAP) has been replaced with a new one (SQLF_DBTN_DB_HEAP). If the old token is used with sqlfudb (Update Database Configuration API), or sqlfxdb (Get Database Configuration API), DB2 will cast 16 bits to 64 or 32 bits, as appropriate, to maintain source code compatibility. If the DBHEAP value is greater than 65535, the cast results in a wrapped value, and DB2 returns a new warning message (SQL5066W; see Chapter 7, Messages).