ANALYZE_STATISTICS_PARTITION

Collects and aggregates data samples and storage information for a range of partitions in the specified table.

Collects and aggregates data samples and storage information for a range of partitions in the specified table. Vertica writes the collected statistics to the database catalog.

You can cancel statistics collection with CTRL+C or meta-function INTERRUPT_STATEMENT.

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

Behavior type

Volatile

Syntax

ANALYZE_STATISTICS_PARTITION ('[[database.]schema.]table', 'min-range-value','max-range-value' [, 'column-list' [, percent ]] )

Returns

0: Success

If an error occurs, refer to vertica.log for details.

Parameters

[database.]schema

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

table
Table on which to collect data.
min-range-value
max-range-value
Minimum and maximum value of partition keys to analyze, where min-range-value must be ≤ max-range-value. To analyze one partition, min-range-value and max-range-value must be equal.
column-list
Comma-delimited list of columns in table, typically a predicate column. Vertica narrows the scope of the data collection to the specified columns.
percent
Float value between 0 and 100 that specifies what percentage of data to read from disk (not the amount of data to analyze). If you omit this argument, Vertica sets the percentage to 10.

Analyzing more than 10 percent disk space takes proportionally longer to process, but produces a higher level of sampling accuracy.

Privileges

Non-superuser:

  • Schema: USAGE

  • Table: One of INSERT, DELETE, or UPDATE

Requirements and restrictions

The following requirements and restrictions apply to ANALYZE_STATISTICS_PARTITION:

  • The table must be partitioned and cannot contain unpartitioned data.

  • The table partition expression must specify a single column. The following expressions are supported:

    • Expressions that specify only the column—that is, partition on all column values. For example:

      PARTITION BY ship_date GROUP BY CALENDAR_HIERARCHY_DAY(ship_date, 2, 2)

    • If the column is a DATE or TIMESTAMP/TIMESTAMPTZ, the partition expression can specify a supported date/time function that returns that column or any portion of it, such as month or year. For example, the following partition expression specifies to partition on the year portion of column order_date:

      PARTITION BY YEAR(order_date)

    • Expressions that perform addition or subtraction on the column. For example:

      PARTITION BY YEAR(order_date) -1

  • The table partition expression cannot coerce the specified column to another data type.

  • Vertica collects no statistics from the following projections:

    • Live aggregate and Top-K projections

    • Projections that are defined to include an SQL function within an expression

Examples

See Collecting partition statistics.