
3-80 IBM Informix OnLine Database Server Administrator’s Guide
Monitor Logging Activity
Executethe-pkor-pKoptionsoftbchecktoobtainallpageinformation.(The
mnemonic -k option refers to “keep all” information.) Execute tbcheck -pk
with a database name or a table name parameter to obtain a listing of the
indexkeyvaluesandthecorrespondingrowidsforeachindexleafpage.Also
listed is the node page to which each leaf page is joined.
Execute the -pl or -pL options of tbcheck to obtain leaf node information.
Execute tbcheck -pl with a database name or a table name parameter to
obtainalistingoftheindexkeyvaluesandthecorrespondingrowidsforeach
index leaf node page. Figure 3-3 illustrates a simple index structure.
Executetbcheck -pc with a databasenameparametertoobtainthefollowing
specific index information organized by table:
■ Number of indexes
■ Data record size
■ Index record size
■ Number of records
Monitor Logging Activity
Monitor logging activity to determine the amount of total available space in
the logical log files and the available space in the current log file.
If the total freespace in thelogicallog files islessthan half ofasingle log file,
OnLine does not create an archive.
Figure 3-3
A simple index
structure
B+ Tree
Root node
Branch nodes
Leaf nodes
Pointer to data (rowids)
Comentarios a estos manuales