COMMANDCACHESTATISTICS 
The system table SYSINFO.COMMANDCACHESTATISTICS contains the statistical information collected about the command cache activities since the last time the database was started. The command cache contains the SQL statements and their execution plans shared by different database sessions (the following refers to the SQL statement and execution plan collectively as a command).
Structure
USABLESIZE |
FIXED(10) |
Size of the command cache (KB) |
USEDSIZE |
FIXED(10) |
Size of the area of the command cache that is actually used (KB) |
USEDSIZEPERCENTAGE |
FIXED(3) |
Size of the area of the command cache that is actually used (%) |
MAXUSEDSIZE |
FIXED(10) |
Maximum used area of the command cache (KB) |
MAXUSEDSIZEPERCENTAGE |
FIXED(3) |
Maximum used area of the command cache (%) |
COMMANDCOUNT |
FIXED(10) |
Number of stored commands |
MAXCOMMANDCOUNT |
FIXED(10) |
Maximum number of stored commands |
INSERTCOMMANDCOUNT |
FIXED(10) |
Number of inserts |
DELETECOMMANDCOUNT |
FIXED(10) |
Number of deletions |
FAILEDALLOCATECOUNT |
FIXED(10) |
Number of memory requests not fulfilled |
CLEANUPTHRESHOLD |
FIXED(10) |
Current threshold value, as of which the command cache will be reorganized for further usage |
CLEANUPCOUNT |
FIXED(10) |
Number of operations that encountered a lack of space in the main memory |
CLEANUPCOMMANDCOUNT |
FIXED(10) |
Number of commands modified due to lack of space in the main memory |
INVALIDATECOUNT |
FIXED(10) |
Number of data definition statements that made execution plans invalid |
CURRENTUNLOADSTATEMENTCOUNT |
FIXED(10) |
Number of SQL statements currently displaced to disk |
UNLOADSTATEMENTCOUNT |
FIXED(10) |
Number of SQL statements displaced to disk |
RELOADSTATEMENTCOUNT |
FIXED(10) |
Number of SQL statements reloaded to the main memory |
DELETEPLANCOUNT |
FIXED(10) |
Number of execution plans deleted due to lack of space in the main memory |
HASHTABLESLOTCOUNT |
FIXED(5) |
Number of slots in the hash table |
USEDHASHTABLESLOTCOUNT |
FIXED(5) |
Number of used slots in the hash table |
MAXUSEDHASHTABLESLOTCOUNT |
FIXED(5) |
Maximum number of used slots in the hash table |
AVGHASHTABLECHAINENTRYCOUNT |
FIXED(5) |
Average length of the hash entry overflow chains |
MAXHASHTABLECHAINENTRYCOUNT |
FIXED(5) |
Maximum length of the hash entry overflow chains |