EXPORT_STATISTICS

Generates statistics in XML format from data previously collected by ANALYZE_STATISTICS.

Generates statistics in XML format from data previously collected by ANALYZE_STATISTICS. Before you export statistics, collect the latest data by calling ANALYZE_STATISTICS.

This is a meta-function. You must call meta-functions in a top-level SELECT statement.

Behavior type

Stable

Syntax

EXPORT_STATISTICS ('[ filename ]' [,'table-spec' [,'column[,...]']])

Arguments

filename

Specifies where to write the generated XML. If filename already exists, EXPORT_STATISTICS overwrites it. If you supply an empty string, EXPORT_STATISTICS writes the XML to standard output.

table-spec

Specifies the table on which to export projection statistics:

  
[[database.]schema.]table

The default schema is public. If you specify a database, it must be the current database.

If table-spec is omitted or set to an empty string, Vertica exports all statistics for the database.

column

The name of a column in table-spec, typically a predicate column. You can specify multiple comma-delimited columns. Vertica narrows the scope of exported statistics to the specified columns.

Privileges

Superuser

Restrictions

EXPORT_STATISTICS does not export statistics for LONG data type columns.

Examples

The following statement exports statistics on the VMart example database to a file:

=> SELECT EXPORT_STATISTICS('/opt/vertica/examples/VMart_Schema/vmart_stats.xml');
        EXPORT_STATISTICS
-----------------------------------
Statistics exported successfully
(1 row)

The next statement exports statistics on a single column (price) from a table named food:

=> SELECT EXPORT_STATISTICS('/opt/vertica/examples/VMart_Schema/price.xml', 'food.price');
        EXPORT_STATISTICS
-----------------------------------
Statistics exported successfully
(1 row)