Sybase 12.4.2 User Manual

Overview of memory use

 

To set buffer cache sizes permanently (that is, until you explicitly reset them) 
use the 

SET OPTION

 statement. Follow the procedure below.

❖

1

If the database whose cache sizes you are changing is not already started, 
start it now:

START DATABASE 

dbfile [AS dbname] [ON engine_name]

2

Set one or both cache sizes.

•

To set the buffer cache size for the IQ Store (the main buffer cache) 
use the following syntax:

SET OPTION "PUBLIC".MAIN_CACHE_MEMORY_MB = 

#_of_MB

•

To set the buffer cache size for the Temporary Store (the temp buffer 
cache) use the following syntax:

SET OPTION "PUBLIC".TEMP_CACHE_MEMORY_MB = 

#_of_MB

-iqmc

 and 

-iqtc

 server 

switches

Reset cache sizes when 
the database is not 
running. Especially useful 
if cache sizes are larger 
than your system can 
accommodate.

From the time the server is 
started until it is stopped

“Setting buffer cache 
size server switches” on 
page 429

-iqsmem

 and 

-iqwmem

 

server switches

Use on some UNIX 
platforms to provide 
additional memory for use 
as buffer caches.

From the time the server is 
started until it is stopped

“Platform-specific 
memory options” on 
page 434

LOAD_MEMORY_MB

 

database option

Indirectly affects buffer 
cache size, by controlling 
the memory that can be 
used for loads. On some 
platforms, allowing 
unlimited memory for 
loads means less memory 
is available for buffer 
caches.

Immediately until you reset 
the option

“Memory for loads, 
synchronizations, and 
deletions” on page 421