aurora_stat_dml_activity
Reports cumulative activity for each type of data manipulation language (DML) operation on a database in an Aurora PostgreSQL cluster.
Syntax
aurora_stat_dml_activity(database_oid)Arguments
- database_oid
-
The object ID (OID) of the database in the Aurora PostgreSQL cluster.
Return type
SETOF record
Usage notes
The aurora_stat_dml_activity function is only available with
Aurora PostgreSQL release 3.1 compatible with PostgreSQL engine 11.6 and later.
Use this function on Aurora PostgreSQL clusters with a large number of databases to identify which databases have more or slower DML activity, or both.
The aurora_stat_dml_activity function returns the number of times the
operations ran and the cumulative latency in microseconds for SELECT, INSERT,
UPDATE, and DELETE operations. The report includes only successful DML
operations.
You can reset this statistic by using the PostgreSQL statistics access function
pg_stat_reset. You can check the last time this statistic was reset
by using the pg_stat_get_db_stat_reset_time function. For more
information about PostgreSQL statistics access functions, see
The Statistics Collector
Examples
The following example shows how to report DML activity statistics for the connected database.
––Define the oid variable from connected database by using \gset=>SELECT oid, datname FROM pg_database WHERE datname=(select current_database()) \gset=>SELECT * FROM aurora_stat_dml_activity(:oid);select_count | select_latency_microsecs | insert_count | insert_latency_microsecs | update_count | update_latency_microsecs | delete_count | delete_latency_microsecs --------------+--------------------------+--------------+--------------------------+--------------+--------------------------+--------------+-------------------------- 178957 | 66684115 | 171065 | 28876649 | 519538 | 1454579206167 | 1 | 53027–– Showing the same results with expanded display on=>SELECT * FROM aurora_stat_dml_activity(:oid);-[ RECORD 1 ]------------+-------------- select_count | 178957 select_latency_microsecs | 66684115 insert_count | 171065 insert_latency_microsecs | 28876649 update_count | 519538 update_latency_microsecs | 1454579206167 delete_count | 1 delete_latency_microsecs | 53027
The following example shows DML activity statistics for all databases in the
Aurora PostgreSQL cluster. This cluster has two databases, postgres and
mydb. The comma-separated list corresponds with the
select_count, select_latency_microsecs,
insert_count, insert_latency_microsecs,
update_count, update_latency_microsecs,
delete_count, and delete_latency_microsecs
fields.
Aurora PostgreSQL creates and uses a system database named rdsadmin to
support administrative operations such as backups, restores, health checks,
replication, and so on. These DML operations have no impact on your Aurora PostgreSQL
cluster.
=>SELECT oid, datname, aurora_stat_dml_activity(oid) FROM pg_database;oid | datname | aurora_stat_dml_activity -------+----------------+----------------------------------------------------------------- 14006 | template0 | (,,,,,,,) 16384 | rdsadmin | (2346623,1211703821,4297518,817184554,0,0,0,0) 1 | template1 | (,,,,,,,) 14007 | postgres | (178961,66716329,171065,28876649,519538,1454579206167,1,53027) 16401 | mydb | (200246,64302436,200036,107101855,600000,83659417514,0,0)
The following example shows DML activity statistics for all databases, organized in columns for better readability.
SELECT db.datname, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 1), '()') AS select_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 2), '()') AS select_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 3), '()') AS insert_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 4), '()') AS insert_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 5), '()') AS update_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 6), '()') AS update_latency_microsecs, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 7), '()') AS delete_count, BTRIM(SPLIT_PART(db.asdmla::TEXT, ',', 8), '()') AS delete_latency_microsecs FROM (SELECT datname, aurora_stat_dml_activity(oid) AS asdmla FROM pg_database ) AS db;datname | select_count | select_latency_microsecs | insert_count | insert_latency_microsecs | update_count | update_latency_microsecs | delete_count | delete_latency_microsecs ----------------+--------------+--------------------------+--------------+--------------------------+--------------+--------------------------+--------------+-------------------------- template0 | | | | | | | | rdsadmin | 4206523 | 2478812333 | 7009414 | 1338482258 | 0 | 0 | 0 | 0 template1 | | | | | | | | fault_test | 66 | 452099 | 0 | 0 | 0 | 0 | 0 | 0 db_access_test | 1 | 5982 | 0 | 0 | 0 | 0 | 0 | 0 postgres | 42035 | 95179203 | 5752 | 2678832898 | 21157 | 441883182488 | 2 | 1520 mydb | 71 | 453514 | 0 | 0 | 1 | 190 | 1 | 152
The following example shows the average cumulative latency (cumulative latency
divided by count) for each DML operation for the database with the OID
16401.
=>SELECT select_count, select_latency_microsecs, select_latency_microsecs/NULLIF(select_count,0) select_latency_per_exec, insert_count, insert_latency_microsecs, insert_latency_microsecs/NULLIF(insert_count,0) insert_latency_per_exec, update_count, update_latency_microsecs, update_latency_microsecs/NULLIF(update_count,0) update_latency_per_exec, delete_count, delete_latency_microsecs, delete_latency_microsecs/NULLIF(delete_count,0) delete_latency_per_exec FROM aurora_stat_dml_activity(16401);-[ RECORD 1 ]------------+------------- select_count | 451312 select_latency_microsecs | 80205857 select_latency_per_exec | 177 insert_count | 451001 insert_latency_microsecs | 123667646 insert_latency_per_exec | 274 update_count | 1353067 update_latency_microsecs | 200900695615 update_latency_per_exec | 148478 delete_count | 12 delete_latency_microsecs | 448 delete_latency_per_exec | 37