approximate_row_count()

Estimate the number of rows in a table

Since 0.10.0

Get approximate row count for , distributed , or regular table based on catalog estimates. This function supports tables with nested inheritance and declarative partitioning.

The accuracy of approximate_row_count depends on the database having up-to-date statistics about the table or , which are updated by VACUUM, ANALYZE, and a few DDL commands. If you have auto-vacuum configured on your table or , or changes to the table are relatively infrequent, you might not need to explicitly ANALYZE your table as shown below. Otherwise, if your table statistics are too out-of-date, running this command updates your statistics and yields more accurate approximation results.

Samples

Get the approximate row count for a single .

ANALYZE conditions;

SELECT * FROM approximate_row_count('conditions');

The expected output:

approximate_row_count
---------------------
               240000

Arguments

The syntax is:

SELECT approximate_row_count('<table_name>');

Name	Type	Default	Required	Description
relation	REGCLASS	-	✔	or regular table to get row count for.

Returns

Column	Type	Description
approximate_row_count	BIGINT	A numeric estimate of the number of rows in the specified table or .