Catalog statistics tables
Statistical information about the size of database tables, indexes, and statistical views is stored in system catalog tables.
The following tables provide a brief description of this statistical
information and show where it is stored.
 The
Table
column indicates whether a particular statistic is collected if the FOR INDEXES or AND INDEXES parameter on the RUNSTATS command is not specified.  The
Indexes
column indicates whether a particular statistic is collected if the FOR INDEXES or AND INDEXES parameter is specified.
 Table 1. Table Statistics (SYSCAT.TABLES and SYSSTAT.TABLES)
 Table 2. Column Statistics (SYSCAT.COLUMNS and SYSSTAT.COLUMNS)
 Table 3. Multicolumn Statistics (SYSCAT.COLGROUPS and SYSSTAT.COLGROUPS)
 Table 4. Multicolumn Distribution Statistics (SYSCAT.COLGROUPDIST and SYSSTAT.COLGROUPDIST)
 Table 5. Multicolumn Distribution Statistics (SYSCAT.COLGROUPDISTCOUNTS and SYSSTAT.COLGROUPDISTCOUNTS)
 Table 6. Index Statistics (SYSCAT.INDEXES and SYSSTAT.INDEXES)
 Table 7. Column Distribution Statistics (SYSCAT.COLDIST and SYSSTAT.COLDIST)
Statistic  Description  RUNSTATS Option  

Table  Indexes  
FPAGES  Number of pages being used by a table  Yes  Yes 
NPAGES  Number of pages containing rows  Yes  Yes 
OVERFLOW  Number of rows that overflow  Yes  No 
CARD  Number of rows in a table (cardinality)  Yes  Yes (Note 1) 
ACTIVE_BLOCKS  For MDC tables, the total number of occupied blocks  Yes  No 
Note:

Statistic  Description  RUNSTATS Option  

Table  Indexes  
COLCARD  Column cardinality  Yes  Yes (Note 1) 
AVGCOLLEN  Average length of a column  Yes  Yes (Note 1) 
HIGH2KEY  Second highest value in a column  Yes  Yes (Note 1) 
LOW2KEY  Second lowest value in a column  Yes  Yes (Note 1) 
NUMNULLS  The number of null values in a column  Yes  Yes (Note 1) 
SUB_COUNT  The average number of subelements  Yes  No (Note 2) 
SUB_DELIM_LENGTH  The average length of each delimiter separating subelements  Yes  No (Note 2) 
Note:

Statistic  Description  RUNSTATS Option  

Table  Indexes  
COLGROUPCARD  Cardinality of the column group  Yes  No 
Statistic  Description  RUNSTATS Option  

Table  Indexes  
TYPE  F = Frequency value
Q = Quantile value 
Yes  No 
ORDINAL  Ordinal number of the column in the group  Yes  No 
SEQNO  Sequence number n that represents the nth TYPE value  Yes  No 
COLVALUE  The data value as a character literal or a null value  Yes  No 
Statistic  Description  RUNSTATS Option  

Table  Indexes  
TYPE  F = Frequency value
Q = Quantile value 
Yes  No 
SEQNO  Sequence number n that represents the nth TYPE value  Yes  No 
VALCOUNT  If TYPE = F, VALCOUNT is the number of occurrences of COLVALUE for the column group with this SEQNO. If TYPE = Q, VALCOUNT is the number of rows whose value is less than or equal to COLVALUE for the column group with this SEQNO.  Yes  No 
DISTCOUNT  If TYPE = Q, this column contains the number of distinct values that are less than or equal to COLVALUE for the column group with this SEQNO. Null if unavailable.  Yes  No 
Statistic  Description  RUNSTATS Option  

Table  Indexes  
NLEAF  Number of index leaf pages  No  Yes 
NLEVELS  Number of index levels  No  Yes 
CLUSTERRATIO  Degree of clustering of table data  No  Yes (Note 2) 
CLUSTERFACTOR  Finer degree of clustering  No  Detailed (Notes 1,2) 
DENSITY  Ratio (percentage) of SEQUENTIAL_PAGES to number of pages in the range of pages that is occupied by the index (Note 3)  No  Yes 
FIRSTKEYCARD  Number of distinct values in the first column of the index  No  Yes 
FIRST2KEYCARD  Number of distinct values in the first two columns of the index  No  Yes 
FIRST3KEYCARD  Number of distinct values in the first three columns of the index  No  Yes 
FIRST4KEYCARD  Number of distinct values in the first four columns of the index  No  Yes 
FULLKEYCARD  Number of distinct values in all columns of the index, excluding any key value in an index for which all record identifiers (RIDs) are marked deleted  No  Yes 
PAGE_FETCH_PAIRS  Page fetch estimates for different buffer sizes  No  Detailed (Notes 1,2) 
AVGPARTITION_CLUSTERRATIO  Degree of data clustering within a single data partition  No  Yes (Note 2) 
AVGPARTITION_CLUSTERFACTOR  Finer measurement of degree of clustering within a single data partition  No  Detailed (Notes 1,2) 
AVGPARTITION_PAGE_FETCH_PAIRS  Page fetch estimates for different buffer sizes, generated on the basis of a single data partition  No  Detailed (Notes 1,2) 
DATAPARTITION_CLUSTERFACTOR  Number of data partition references during an index scan  No (Note 6)  Yes (Note 6) 
SEQUENTIAL_PAGES  Number of leaf pages located on disk in index key order, with few, or no large gaps between them  No  Yes 
AVERAGE_SEQUENCE_PAGES  Average number of index pages that are accessible in sequence; this is the number of index pages that the prefetchers can detect as being in sequence  No  Yes 
AVERAGE_RANDOM_PAGES  Average number of random index pages between sequential page accesses  No  Yes 
AVERAGE_SEQUENCE_GAP  Gap between sequences  No  Yes 
AVERAGE_SEQUENCE_FETCH_PAGES  Average number of table pages that are accessible in sequence; this is the number of table pages that the prefetchers can detect as being in sequence when they fetch table rows using the index  No  Yes (Note 4) 
AVERAGE_RANDOM_FETCH_PAGES  Average number of random table pages between sequential page accesses when fetching table rows using the index  No  Yes (Note 4) 
AVERAGE_SEQUENCE_FETCH_GAP  Gap between sequences when fetching table rows using the index  No  Yes (Note 4) 
NUMRIDS  The number of RIDs in the index, including deleted RIDs  No  Yes 
NUMRIDS_DELETED  The total number of RIDs in the index that are marked deleted, except RIDs on those leaf pages where all RIDs are marked deleted  No  Yes 
NUM_EMPTY_LEAFS  The total number of leaf pages on which all RIDs are marked deleted  No  Yes 
INDCARD  Number of index entries (index cardinality)  No  Yes 
Note:

Statistic  Description  RUNSTATS Option  

Table  Indexes  
DISTCOUNT  If TYPE = Q, DISTCOUNT is the number of distinct values that are less than or equal to COLVALUE statistics  Distribution (Note 2)  No 
TYPE  Indicator of whether the row provides frequentvalue or quantile statistics  Distribution  No 
SEQNO  Frequency ranking of a sequence number to help uniquely identify the row in the table  Distribution  No 
COLVALUE  Data value for which a frequency or quantile statistic is collected  Distribution  No 
VALCOUNT  Frequency with which the data value occurs in a column; for quantiles, the number of values that are less than or equal to the data value (COLVALUE)  Distribution  No 
Note:
