Product Documentation

Database Administrator's Guide

Previous Topic

Next Topic

Cache and Memory

FairCom DB allows extremely fine tuned cache and memory management beyond basic data cache and index cache pool sizes. This section covers options that control this granularity, including per user memory limits.

 
NONTRAN_DATA_FLUSH_SEC, NONTRAN_INDEX_FLUSH_SEC, TRAN_DATA_FLUSH_SEC, TRAN_INDEX_FLUSH_SEC

Configure a fixed rate of background flushing of updated data cache pages and index cache.

 
BUFBLK_RATIO

Specifies the number of index cache pages in each block list mutex.

 
BUFFER_RUNLENGTH

Specifies the number of consecutive write operations performed while walking a list of buffer/cache pages before allowing other threads to acquire control of the list.

 
BUFR_MEMORY

Specifies the size of memory blocks the FairCom Server uses in conjunction with data and index caches.

 
COMPATIBILITY LARGE_CACHE

Permits the DAT_MEMORY and IDX_MEMORY values to be reinterpreted as megabytes instead of bytes.

 
CACHE_STAT_ARRAY_SIZE

Override the number of cache hit counters.

 
COMPATIBILITY MINIMUM_INDEX_BUFFERS

Restores behavior prior to V11 where the index cache memory was expanded past the specified limit to allow more concurrent index threads.

 
DATA_LRU_LISTS

Specifies how many LRU lists are maintained for data cache pages. Note: The LRU algorithm is no longer used for the data cache.

 

Dynamic Data and Index Cache

Allows changing data and index cache sizes without restarting the FairCom Server.


GUEST_MEMORY

Specifies the memory usage limit in bytes for a user without a User ID.

 
INDEX_LRU_LISTS

Specifies how many LRU lists are maintained for index cache pages.

 
LIST_MEMORY

Specifies the size of memory “chunks” the FairCom Server uses for various internal data structures.

 
LMT_MEMORY

Sets the maximum size for a single allocation using the FairCom DB memory suballocator.

 
MEMORY_HASH

Causes 8 times the specified number of lists to be created (8 for each internal memory suballocator).

 
MPAGE_CACHE

When set to a non-zero value, N, causes records falling within N+2 cache pages to be stored entirely within the cache.

 
NONTRAN_FILESYS_FLUSH_OFF

When set to Yes, suppresses calls to flush updated file system cache pages to disk for all non-TRNLOG data and index files.

 
NO_CACHE

Specifies files that are NOT be cached.

 
PRIME_CACHE and PRIME_INDEX (PRIME_CACHE, Prime Cache)

Specifies data and index files are added to the priming list and the number of bytes to be loaded into cache when physically opening the file.

 
PRIME_CACHE_BY_KEY

Prime be the data cache from the specified file with the specified number of bytes by the specified index in forward or reverse order.

 
SORT_MEMORY

Specifies the size of sort buffers used by the FairCom Server.

 
SPECIAL_CACHE_FILE

Dedicates a specified amount of cache memory to a particular Extended data file.

 
TOT_MEMORY

Note: TOT_MEMORY is a deprecated keyword. FairCom does not recommend setting a total memory limit.

Specifies the total number of bytes the system will attempt to allocate for all uses (including index and data caches specified by the IDX_MEMORY and DAT_MEMORY keywords).

 
USR_MEM_RULE

Sets the system default rule for FairCom Server action when a user exceeds his/her memory limit.

 
USR_MEMORY

Specifies the system default limit of memory (in bytes) available to each user.

In This Section

*_FLUSH_SEC background flush rate reduces contention

BUFBLK_RATIO

BUFFER_RUNLENGTH

BUFR_MEMORY

CACHE_STAT_ARRAY_SIZE

COMPATIBILITY LARGE_CACHE

COMPATIBILITY MINIMUM_INDEX_BUFFERS

DAT_MEMORY

DATA_LRU_LISTS

GUEST_MEMORY

IDX_MEMORY

INDEX_LRU_LISTS

LIST_MEMORY

LMT_MEMORY

MEMORY_HASH

MPAGE_CACHE

NO_CACHE

NONTRAN_FILESYS_FLUSH_OFF

PRIME_CACHE

PRIME_CACHE_AT_STARTUP

PRIME_INDEX

PRIME_CACHE_BY_KEY

SET_CACHE_OPTIONS

SORT_MEMORY

SPECIAL_CACHE_FILE

SPECIAL_CACHE_PERCENT

TOT_MEMORY

USR_MEM_RULE

USR_MEMORY

TOCIndex