# db2_statistics

(PECL ibm_db2 >= 1.0.0)

db2_statistics — Returns a result set listing the index and statistics for a table

### 说明

db2_statistics ( resource `$connection` , string `$qualifier` , string `$schema` , string `$table-name` , bool `$unique` ) : resource

Returns a result set listing the index and statistics for a table.

### 参数

`connection`

  A valid connection to an IBM DB2, Cloudscape, or Apache Derby database.

`qualifier`

  A qualifier for DB2 databases running on OS/390 or z/OS servers. For other databases, pass `NULL` or an empty string.

`schema`

  The schema that contains the targeted table. If this parameter is `NULL`, the statistics and indexes are returned for the schema of the current user.

`table_name`

  The name of the table.

`unique`

  An integer value representing the type of index information to return.

  `0`

    Return only the information for unique indexes on the table.

  `1`

    Return the information for all indexes on the table.

### 返回值

Returns a statement resource with a result set containing rows describing the statistics and indexes for the base tables matching the specified parameters. The rows are composed of the following columns:

Column name | Description
--- | ---
TABLE_CAT | The catalog that contains the table. The value is `NULL` if this table does not have catalogs.
TABLE_SCHEM | Name of the schema that contains the table.
TABLE_NAME | Name of the table.
NON_UNIQUE | An integer value representing whether the index prohibits unique values, or whether the row represents statistics on the table itself:
Return value | Parameter type
--- | ---
0 (SQL_FALSE) | The index allows duplicate values.
1 (SQL_TRUE) | The index values must be unique.
`NULL` | This row is statistics information for the table itself.
INDEX_QUALIFIER | A string value representing the qualifier that would have to be prepended to INDEX_NAME to fully qualify the index.
INDEX_NAME | A string representing the name of the index.
TYPE | An integer value representing the type of information contained in this row of the result set:
Return value | Parameter type
--- | ---
0 (SQL_TABLE_STAT) | The row contains statistics about the table itself.
1 (SQL_INDEX_CLUSTERED) | The row contains information about a clustered index.
2 (SQL_INDEX_HASH) | The row contains information about a hashed index.
3 (SQL_INDEX_OTHER) | The row contains information about a type of index that is neither clustered nor hashed.
ORDINAL_POSITION | The 1-indexed position of the column in the index. `NULL` if the row contains statistics information about the table itself.
COLUMN_NAME | The name of the column in the index. `NULL` if the row contains statistics information about the table itself.
ASC_OR_DESC | A if the column is sorted in ascending order, D if the column is sorted in descending order, `NULL` if the row contains statistics information about the table itself.
CARDINALITY | If the row contains information about an index, this column contains an integer value representing the number of unique values in the index. If the row contains information about the table itself, this column contains an integer value representing the number of rows in the table.
PAGES | If the row contains information about an index, this column contains an integer value representing the number of pages used to store the index. If the row contains information about the table itself, this column contains an integer value representing the number of pages used to store the table.
FILTER_CONDITION | Always returns `NULL`.

### 参见

- db2_column_privileges() - Returns a result set listing the columns and associated privileges for a table
- db2_columns() - Returns a result set listing the columns and associated metadata for a table
- db2_foreign_keys() - Returns a result set listing the foreign keys for a table
- db2_primary_keys() - Returns a result set listing primary keys for a table
- db2_procedure_columns() - Returns a result set listing stored procedure parameters
- db2_procedures() - Returns a result set listing the stored procedures registered in a database
- db2_special_columns() - Returns a result set listing the unique row identifier columns for a table
- db2_table_privileges() - Returns a result set listing the tables and associated privileges in a database
- db2_tables() - Returns a result set listing the tables and associated metadata in a database