analyze_threshold_percent - Amazon Redshift

analyze_threshold_percent

Values (default in bold)

10, 0 to 100.0

Description

Sets the threshold for percentage of rows changed for analyzing a table. To reduce processing time and improve overall system performance, Amazon Redshift skips ANALYZE for any table that has a lower percentage of changed rows than specified by analyze_threshold_percent. For example, if a table contains 100,000,000 rows and 9,000,000 rows have changed since the last ANALYZE, then by default the table is skipped because fewer than 10 percent of the rows have changed. To analyze tables when only a small number of rows have changed, set analyze_threshold_percent to an arbitrarily small number. For example, if you set analyze_threshold_percent to 0.01, then a table with 100,000,000 rows will not be skipped if at least 10,000 rows have changed. To analyze all tables even if no rows have changed, set analyze_threshold_percent to 0.

You can modify the analyze_threshold_percent parameter for the current session only by using a SET command. The parameter can't be modified in a parameter group.

Example

set analyze_threshold_percent to 15; set analyze_threshold_percent to 0.01; set analyze_threshold_percent to 0;