postgresqlHow can I view query statistics in PostgreSQL?
To view query statistics in PostgreSQL, you can use the EXPLAIN
command. This command will show you the execution plan for a given query. This plan will include information about the cost of each operation in the query, as well as the estimated number of rows that will be returned.
For example, the following query will show the execution plan for a SELECT statement:
EXPLAIN SELECT * FROM mytable;
The output of this command might look like this:
QUERY PLAN
------------------------------------------------------------------------------------------------
Seq Scan on mytable (cost=0.00..2.00 rows=100 width=20)
(1 row)
The output shows that the query will do a sequential scan of the table, with a cost of 2 and an estimated number of rows of 100.
You can also use the ANALYZE
command to get more detailed query statistics. This command will run the query and collect statistics about the query execution.
For example, the following query will analyze a SELECT statement:
ANALYZE SELECT * FROM mytable;
The output of this command might look like this:
QUERY PLAN
------------------------------------------------------------------------------------------------
Seq Scan on mytable (cost=0.00..2.00 rows=100 width=20)
(1 row)
Time: 0.002s
The output shows the same query plan as before, but also includes the time it took to execute the query (in this case, 0.002s).
You can find more information about the EXPLAIN
and ANALYZE
commands in the PostgreSQL documentation.
More of Postgresql
- How can I use PostgreSQL with YAML?
- How can I troubleshoot zero damaged pages in PostgreSQL?
- How do I use PostgreSQL's XMIN and XMAX features?
- How do I set the PostgreSQL work_mem parameter?
- How can I use PostgreSQL's "zero if null" feature?
- How can I monitor PostgreSQL performance using Zabbix?
- How can I retrieve data from PostgreSQL for yesterday's date?
- How do I use PostgreSQL's XMLTABLE to parse XML data?
- How do I use PostgreSQL variables in my software development project?
- How can I use PostgreSQL and ZFS snapshots together?
See more codes...