* Denormalize prepared statement queries
Added support for extracting query arguments for prepared statements
when `pg_stat_monitor.pgsm_normalized_query` is off.
Previously pg_stat_monitor was unable to extract the arguments for
prepared statements, thus leaving queries with placeholders $1
.. $N instead of the actual arguments.
* Optmize query denormalization
Instead of copying original query text byte by byte, copy data between
query placeholders in chunks, example:
`INSERT INTO foo(a, b, c) VALUES('test', 100, 'test again)'`
Would result in normalized query:
`INSERT INTO foo(a, b, c) VALUES($1, $2, $3)`
The original patch would copy the parts between placeholders byte by
byte, e.g. `INSERT INTO foo(a, b, c) VALUES(`, instead we can copy this
whole block at once, 1 function call and maybe 1 buffer re-allocation
per call.
Also make use of `appendBinaryStringInfo` to avoid calculating string
length as we have this info already.
* Optmize query denormalization(2)
Avoid allocating an array of strings for extracting query argument
values, instead append the current parameter value directly in the
buffer used to store the denormalized query.
This avoids not only unnecessary memory allocations, but also copying
data between temporary memory and the buffer.
* Store denormalized query only under certain constraints
This commit introduces a little optimization along with a feature, it
stores the query in denormalized form only under the circumstances
below:
- The psgm_normalized_query GUC is disabled (off).
- The query is seem for the first time, or the query total
execution time exceeds the mean execution time calculated for
the previous queries.
Having the query which took most execution time along with it's
arguments could help users in further investigating performance issues.
* Fix regression tests
When query normalization is disabled utility queries like SELECT 10+20
are now stored as is, instead of SELECT $1+$2.
Also when functions or sub queries are created the arguments used
internally by the function or subqueries will be replaced by NULL instead
of $1..$N. The actual arguments will be displayed when the function or
subquery is actually invoked.
* Add query denormalization regression test for prepared statements
Ensures that the denormalization of prepared statements is working, also
ensure that a query which takes more time to execute replaces the
previous denormalized query.
* Updated pgsm_query_id regression tests
With the query dernomalization feature, having integer literals used in
sql like 1, or 2 could create some confusion on whether those are
placeholders or constant values, thus this commit updates the
pgsm_query_id regression test to use different integer literals to avoid
confusion.
* Improve query denormalization regression test
Add a new test case:
1. Execute a prepared statement with larger execution time first.
2. Execute the same prepared statement with cheap execution time.
3. Ensures that the denormalized heavy query is not replaced by the
cheaper.
* Format source using pgindent
* Fix top query regression tests on PG 12,13
On PG 12, 13, the internal return instruction in the following function:
```
CREATE OR REPLACE FUNCTION add(int, int) RETURNS INTEGER AS
$$
BEGIN
return (select $1 + $2);
END; $$ language plpgsql;
```
Is stored as SELECT (select expr1 + expr2)
On PG 14 onward it's stored just as SELECT (expr1 + expr2)
* PG-592: Treat queries with different parent queries as separate entries
1. Previously pg_stat_monitor had a `topquery` and `topqueryid` field, but it was only a sample:
it showed one of the top queries executing the specific query.
With this change, the same entry executed by two different functions will result in two entries in the statistics table.
2. This also fixes a bug where the content of these field disappeared for every second query executed:
previously the update function changed topqueryid to `0` if it was non zero, and changed it to the proper id when it was 0.
This resulted in an alternating behavior, where for every second executed query the top query disappeared.
After these changes, the top query is always shown.
3. The previous implementation also leaked dsa memory used to store the parent queries. This is now also fixed.
* PG-502: Fixing review comments
* dsa_free changed to assert as it can never happen
* restructured the ifs to be cleaner
Note: kept the two-level ifs, as that makes more sense with the assert
Note: didn't convert nested_level checks to macro, as it is used differently at different parts of the code
* PG-502: Fixing review comments
* PG-592 Add regression test
* Make test compatible with PG12
* Remove redundant line
---------
Co-authored-by: Artem Gavrilov <artem.gavrilov@percona.com>
* Temporary disable all workflows
* Add build workflow with PG17
* Fix incompatibilities
* Fix 007_settings_pgsm_query_shared_buffer.pl test
* Fix 018_column_names.pl
* Fix 025_compare_pgss.pl
* Remove tuplestore_donestoring usage at all
* Rename I/O timing statistics columns to shared_blk_{read|write}_time
* Fix comments with fileds numbers
* Fix format
* Revert "Temporary disable all workflows"
This reverts commit 12e75beb63.
* Disable all workflows except check and build for PG 15, 16 and 17
* Fix
* Fix comments
* Fix migration
* Use REL_17_BETA1 in CI
* Add timers tests to 028_temp_block.pl
* Add local blocks timing statistics columns local_blk_{write|read}_time
* Fix t/027_local_blocks.pl test for older PG versions
* Fix
* Add jit_deform_{count|time} metrics
* Fix
* Add stats_since and minmax_stats_since fields
* Revert "Disable all workflows except check and build for PG 15, 16 and 17"
This reverts commit 73febf3aee.
* Fix t/028_temp_block.pl for PG14 and below
* Fix build for PG12
* Add pgdg workflow for PG17
* Try to fix PG pgdg workflow
* Fixes and formatting
* Format code
* Add level tracking regression test
* Fix nesting level tracking
* Format code
* Add level tracking test expected result for PG13
* Fix for PG12
* Skip level tracking regression test for PG version less than 14
* Fix toplevel calculation for older PG version
* Fix level tracking test results
* Fix nesting level counting for older PG version
* Revert "Fix nesting level counting for older PG version"
This reverts commit 3e91da8010.
* Fix level tracking for older PG versions once again
* Set REL_17_BETA2 tag for PG
* Add CI badge for PG17
* Use PG17 for examples in readme
This bug uncovered serious issues with how the data was being stored by PSGM.
So it require a complete redesign.
pg_stat_monitor now stores the data locally within the backend process's local
memory. The data is only stored when the query completes. This reduces the
number of lock acquisitions that were previously needed during various stages
of the execution. Also, this avoids data loss in case the current bucket
changes during execution. Also, the unavailability of jumble state during later
stages of executions was causing pg_stat_monitor to save non-normalized query.
This was a major problem as well.
pg_stat_monitor specific memory context is implemented. It is used for saving
data locally. The context memory callback helps us clear the locally saved data
so that we do not store it multiple times in the shared hash.
As part of this major rewrite, pgss reference in function and variable names
is changed to pgsm. Memory footprint for the entries is reduced, data types
are corrected where needed, and we've removed unused variables, functions and
macros.
This patch was mutually created by:
Co-authored-by: Hamid Akhtar <hamid.akhtar@percona.com>
Co-authored-by: Muhammad Usama <muhammad.usama@percona.com>
Disallow V1 API to be used with V2.0 lib and remove pg_stat_monitor--1.0.sql
as part of that. A few adjustments to 1.x to 2.0 upgrade script are also
part of the commit
Regardless of the database or the user, the same query will yield the
same query ID. As part of this, a new column, 'pgsm_query_id', is added.
* pgsm_query_id:
pgsm_query_id has the same data type of int8 as the queryid column. If
the incoming SQL command includes any constants, it internally normalizes
the query to remove those constant values with placeholders. Otherwise,
it uses the query directly to generate the query hash.
Since we no longer depend on the server's parse tree mechanism, we can
generate the same hash for the same query text for all server versions.
Also, it is important to note that the hash being calculated is a database,
schema and user independent. So same query text in different databases
will generate the same hash.
This column is not part of the key; rather, for observability purposes only.
* Regression
SQL test case pgsm_query_id.sql is added to the SQL regression.
pg_stat_monitor is a bit longer; therefore, it requires some code cleanup.
Therefore I decided to turn these tasks into multiple commits and PR to avoid
various changes in one PR. This will ease the review and Q/A process.
In this commit, I have done these tasks.
1 - Delete all the SQL.in files because these version-dependent files
are becoming significant in quantity. Now added a single SQL file for which
contains the dynamic SQL based on the PostgreSQL Version.
2 - New SQL files (pg_stat_monitor--2.0.sql) added for pg_stat_monitor version 2.
3 - A new SQL file (pg_stat_monitor--1.0--2.0.sql) is created, which will be
used to upgrade from version 1.0 to 2.0. Currently, this file is empty. But
whenever we add some API changes into 2.0, we need to update that file too.
4 - The control file (pg_stat_monitor.control) is updated for version 2.0.
This change will make the CREATE EXTENSION default to pg_stat_monitor version 2.0
The Makefile is refactored and unnecessary conditional statements are removed
in favor of handling version separately.
Also, the clean target is updated to remove generated files including results
folder and the ${DATA} file.
This commit brings following changes to this branch:
1) Port changes/additions TAP testing from main branch to this branch, under PG-292.
2) Changes to test cases due to GUCs change, under PG-331.
3) Call counts verfications, under PG-338.
4) Changes to github workflows to accomodate automation for TAP testing, under PG-343.
This commit adds following three sql based testcases:
1) Test unique application name set by user.
2) Histogram function is working properly as desired.
3) Error on insert is shown with proper message.
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).
Artem Gavrilov
Diego Fronza
Zsolt Parragi
Mikail
Hamid Akhtar
Muhammad Usama
Naeem Akhter
Ibrar Ahmed
Hamid Akhtar
Naeem Akhter
Vadim Yalovets
Ibrar Ahmed
Mikhail Samoylov