IOBUFFERCACHES 
The system table SYSINFO.IOBUFFERCACHES contains information on using the IO buffer cache, which is dimensioned by the database parameter CacheMemorySize.
Structure
TOTALSIZE |
FIXED(20) |
Configured size of the I/O buffer cache according to the database parameter CacheMemorySize (KB) |
DATACACHEUSEDSIZE |
FIXED(20) |
Pages used by the data cache (KB) |
CONVERTERUSEDSIZE |
FIXED(20) |
Pages used by the converter (KB) |
LOGQUEUEUSEDSIZE |
FIXED(20) |
Pages used by the log queue (KB) |
IOMANAGEMENTUSEDSIZE |
FIXED(20) |
Pages used by I/0 Management (KB) |
FILEDIRECTORYUSEDSIZE |
FIXED(20) |
Pages used by the internal file directory (KB) |
RESTARTRECORDUSEDSIZE |
FIXED(20) |
Restart pages that are used for snapshots (KB) |
BLOCKALLOCATORUSEDSIZE |
FIXED(20) |
Memory used by block allocators (KB) |
UNUSEDSIZE |
FIXED(20) |
Unused pages (KB) |
INDEXCREATIONUSEDSIZE |
FIXED(20) |
Pages used for parallel index creation (KB) |