COMMANDCACHESTATISTICS

Definition

The system table COMMANDCACHESTATISTICS contains the statistical information collected about the command cache activities since the last time the database instance 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

COMMANDCACHESTATISTICS

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 deletes

FAILEDALLOCATECOUNT

FIXED(10)

Number of memory requests not fulfilled

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

See also:

COMMANDCACHESTATISTICSRESET