A tabela SYSKEYTGTDIST contém uma ou mais linhas para o primeiro destino-chave de uma chave de índice estendida.
O esquema é SYSIBM.
As linhas nesta tabela podem ser inseridas, atualizadas e excluídas.
Importante:
Tenha cuidado ao emitir instruções SQL ou usar ferramentas para atualizar os valores das estatísticas nas tabelas do catálogo.
Se essas atualizações introduzirem dados inválidos, resultados imprevisíveis podem ocorrer, incluindo abends para RUNSTATS e outros utilitários.
Se esses problemas ocorrerem, você pode executar o utilitário RUNSTATS e coletar estatísticas no nível do espaço de tabela para resolver os problemas, na maioria
dos casos.
The SYSKEYTGTDIST table contains one or more rows for the first key-target of an extended index key.
The schema is SYSIBM.
Rows in this table can be inserted, updated, and deleted.
Important:
Use care when issuing SQL statements or using tools to update statistics values in catalog tables.
If such updates introduce invalid data, unpredictable results can occur, including abends for RUNSTATS and other utilities.
If such problems occur, you can run the RUNSTATS utility and collect statistics at the table space level to resolve the problems, in most cases.
| Column name |
Data type |
Description |
Use |
| STATSTIME |
TIMESTAMP
NOT NULL
WITH DEFAULT |
If RUNSTATS or another utility with inline statistics updated the statistics, the date and time when the last utility invocation updated the statistics.
The default value is '0001-01-01-00.00.00.000000'.
The default value indicates that statistics were not collected.
This is an updatable column. |
G |
| IBMREQD |
CHAR(1)
NOT NULL |
A value of Y indicates that the row came from the basic machine-readable material (MRM) tape.
For all other values, see Release dependency indicators.
The value in this field is not a reliable indicator of release dependencies. |
G |
| IXSCHEMA |
VARCHAR(128)
NOT NULL |
The qualifier of the index. |
G |
| IXNAME |
VARCHAR(128)
NOT NULL |
The name of the index. |
G |
| KEYSEQ |
SMALLINT
NOT NULL |
The numeric position of the key-target in the index. |
G |
| KEYVALUE |
VARCHAR(2000)
NOT NULL
WITH DEFAULT
FOR BIT DATA |
KEYVALUE contains the data of a frequently occurring value. If the value has a non-character data type, the data might not be printable. |
S |
| TYPE |
CHAR(1)
NOT NULL
WITH DEFAULT 'F' |
The type of statistics that are gathered:
- C
- Cardinality
- F
- Frequent value
- N
- Non-padded frequent value
- H
- Histogram statistics
|
G |
| CARDF |
FLOAT
NOT NULL
WITH DEFAULT -1 |
When TYPE='C', CARDF contains the number of distinct values for the key group.
When TYPE='H', CARDF contains the number of distinct values for the key group in a quantile indicated by QUANTILENO. |
S |
| KEYGROUPKEYNO |
VARCHAR(254)
NOT NULL
WITH DEFAULT
FOR BIT DATA |
KEYGROUPKEYNO contains a value that identifies the set of keys that are associated with the statistics.
KEYGROUPKEYNO contains 0 if the statistics are only associated with a single key.
If the statistics are associated with more than a single key, KEYGROUPKEYNO contains an array of SMALLINT key numbers with a dimension that is equal to the
value in NUMKEYS. |
S |
| NUMKEYS |
SMALLINT
NOT NULL
WITH DEFAULT -1 |
The number of keys that are associated with the statistics.
The value is always 1 when the object is an XML index. |
G |
| FREQUENCYF |
FLOAT
NOT NULL
WITH DEFAULT -1 |
When TYPE='F' or 'N', FREQUENCYF contains a value that indicates the percentage of entries in the index that have the value that is contained in
the KEYVALUE column.
When TYPE='H', FREQUENCYF contains a value that indicates the percentage of entries in the index that have a value that is in the range of the quantile that is
indicated in the QUALTILENO column.
To determine the percentage from the value of FREQUENCYF, multiply the value by 100.
For example, a value of '1' indicates 100 percent.
A value of '.153' indicates '15.3' percent. |
G |
| QUANTILENO |
SMALLINT
NOT NULL
WITH DEFAULT -1 |
QUANTILENO contains an ordinary sequence number of a quantile in the whole consecutive value range, from low to high. |
G |
| LOWVALUE |
VARCHAR(2000)
NOT NULL
WITH DEFAULT
FOR BIT DATA |
When TYPE='H', LOWVALUE contains the lower bound for the quantile that is in QUANTILENO.
LOWVALUE is not used if TYPE does not equal 'H'. |
G |
| HIGHVALUE |
VARCHAR(2000)
NOT NULL
WITH DEFAULT
FOR BIT DATA |
When TYPE='H', HIGHVALUE contains the upper bound for the quantile that is in QUANTILENO.
HIGHVALUE is not used if TYPE does not equal 'H'. |
G |
