Instead of trying to fix every case where we could throw an error and
handling that properly we just make sure to disable the error capture
of the hook while our backend holds the lock.
We keep the check for IsSystemOOM() in the hook even though that might
not be relevant anymore because if we are in OOM it is not like there
would be any point to log the error anyway.
This is done via a global variable, similar to the
__pgsm_do_not_capture_error variable that we are replacing, which we
also use in one place to disable recursive calls to the log hook
where we do not hold the lock.
A potential future improvement would be to make this variable a counter,
or have two separate globals, so that we could guard against recursive
calls to the hook running us out of stack and not just prevent the
deadlocks.
* 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>
* Cache application name for every backed instance
* Improve pg_get_backend_status performance for PG16 and PG17
* Fix
* Make application_name tracking disabled by default
* Meke app name tracking opt-out
* Format newly added code with pgindent
* Fix build for PG17
* Fix
* 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
dependabot[bot]
Andreas Karlsson
Artem Gavrilov
Muhammad Aqeel
Artem Gavrilov
StepSecurity Bot
Diego Fronza
Zsolt Parragi