We are concerned with finished queries in pg_stat_monitor, so state and
state_code columns were removed from the pg_stat_monitor_view as we only
list finished queries on it.
Removed state regression as it is not necessary anymore.
Also, this allowed us to remove the call to pgss_store on ExecutorStart,
which just updated query state to EXEC, thus saving some CPU.
The pg_stat_monitor_errors view was created in order to help inspecting
internal errors that may occur in pg_stat_monitor module itself, it
contains the error message, its severity, the last time the error occurred
and the number of times that any given error ocurred.
Implementation details:
- A new lwlock was added to the pgssSharedState structure in order to
control access to the errors hash table.
- Increased RequestNamedLWLockTranche() no. of locks requested to 2.
- The function GetNamedLWLockTranche() returns an array of locks, we
use the first lock for controlling access to the usual buckets hash
table, and the second one to control access to the errors hash table.
- During module initialization (_PG_init) we increased the amount of
shared memory space requested to include space to the new errors hash
table: RequestAddinShmemSpace(... + pgsm_errors_size())
- The implementation in pgsm_errors.c simple uses a hash table to track
error messages, the message is also used as the key.
Issue - (#16): PG-112: Change the column name "ip" to "client_ip" for readability purpose.
Issue - (#17): PG-111: Show all the queries from complete and incomplete buckets.
Issue - (#18): PG-108: Log the bucket start time.
Issue - (#19): PG-99: Response time histogram.
Issue - (#20): PG-97: Log CPU time for a query.
Issue - (#21): PG-96: Show objects(tables) involved in the query.
Issue - (#22): PG-93: Retain the bucket, and don't delete the bucket automatically.
Issue - (#23): PG-91: Log queries of all the databases.
Issue - (#24): PG-116: Restrict the query size.
Issue - (#3) : README file update.
Support for database/user/client based aggregates added to access
these statistics with three new views added. Some new counters added
including min/max/mean's time histograms. We are saving the parameters
of the slow queries, which can be tested later. Did some refactoring
of the code, by renaming the whole extension from pg_stat_statement to
pg_stat_monitor.
The pg_stat_monitor is based on PostgreSQL-11's pg_stat_statement.
To keep track of the changes, this is the base code of
PostgreSQL's pg_stat_statement.
(commit = d898edf4f233a3ffe6a0da64179fc268a1d46200).
Diego Fronza
Vadim Yalovets
Ibrar Ahmed
Mikhail Samoylov