I want to log the actual sql statements executed against a POSTGRES instance. I am aware that I can enable logging of the sql statements. Unfortunately, this doesn't log the actual sql, but rather a parsed version, with certain parameters stripped out and listed separately.
Is there a tool for reliably reconstituting this output into executable sql statements?
Or is there a way of intercepting the sql that is send to the postgres instance, such that that sql can be logged?
We want to be able to replay these sql statements against another database.
Thanks for your help!
Actually, PostgreSQL does log exactly the SQL that got executed. It doesn't strip parameters out. Rather, it doesn't interpolate them in, it logs what the application sent, with bind parameters separate. If your app sends insert into x(a,b) values ($1, $2) with bind params 42 and 18, that's what gets logged.
There's no logging option to interpolate bind parameters into the query string.
Your last line is the key part. You don't want logging at all. You're trying to do statement based replication via the logs. This won't work well, if at all, due to volatile functions, the search_path, per-user settings, sequence allocation order/gap issues, and more. If you want replication don't try to do it by log parsing.
If you want to attempt statement-based replication look into PgPool-II. It has a limited ability to do so, with caveats aplenty.
Via setting log_statement to all on postgresql.conf. See the documentation for runtime-config-logging
Related
I often have to execute complex sql scripts in a single transaction on a large PostgreSQL database and I would like to verify everything that was changed during the transaction.
Verifying each single entry on each table "by hand" would take ages.
Dumping the database before and after the script to plain sql and using diff on the dumps isn't really an option since each dump would be about 50G of data.
Is there a way to show all the data that was added, deleted or modified during a single transaction?
Dude, What are you looking for is the most searchable thing on the internet when it comes to capturing Database changes. It is a kind of version control we can say.
But as long as I know, sadly there are no in-built approaches are available in PostgreSQL or MySql. But you can overcome it by setting/adding some triggers for your most usable operations.
You can create some backup schemas, and tables to capture your changes that are changed(updated), created, or deleted.
In this way you can achieve what you want. I know this process is fully manual, But really effective.
If you need to analyze the script's behaviour only sporadically, then the easiest approach would be to change server configuration parameter log_min_duration_statement to 0 and then back to any value it had before the analysis. Then all of the script activity will be written to the instance log.
This approach is not suitable if your storage is not prepared to accommodate this amount of data, or for systems in which you don't want sensitive client data to be written to a plain-text log file.
Is there any way/tool to trace and debug a query in PostgreSQL 9.3.18?
I'm a SQL programmer and sometimes I need to trace and debug my queries and see the values of different fields at execution time. I've Googled this but didn't get any relevant result.
Any idea would be appreciated
PG Admin (database interaction GUI) that is sometimes bundled with PostgreSQL includes a step through debugger for query/calls to Postgres database functions (as opposed to every query that goes to the server).
https://www.pgadmin.org/docs/pgadmin4/4.29/debugger.html
Before using it you have to enable it as a plugin/library in PG Admin.
The debugger will step to statements so sometimes a complex single statement will execute without letting you step through it's details. Still, if you need to see a basic step through of a longer multi statement function or variable values at some points it can be useful. Note, this debug applies to database functions and not general queries.
I need to log all activity for some specific user on database. I have set up the logging with ALTER ROLE username SET log_statement TO 'all'; and the logging works fine, all queries from user are logged. The problem is that for this user queries to Postgres internal schemas (pg_catalog) from clients like psql and pgAdmin are also logged. I have a bunch of lines with SELECT pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname).... in the log that are of no use to me. Even worse this queries are more then one line in the log so it's not easy to filter them out.
Is it possible to somehow restrict the logging only to one specific database or schema and not to include queries to other schemas like pg_catalog?
I don't know if the standard logging utility in postgres has that option (my guess is no). But maybe it's worth a look to the pgaudit external library for postgres.
The module pgadmin is designed to generate audit logs, but it uses the standard postgres logging tool. You can tweak several parameters to customize the logs, and it has a specific parameter that I think is perfect for your use case. From the documentation:
pgaudit.log_catalog
Specifies that session logging should be enabled in the case where all
relations in a statement are in pg_catalog. Disabling this setting
will reduce noise in the log from tools like psql and PgAdmin that
query the catalog heavily.
The default is on.
I hope it helps!
Change your logging format from text to csv (log_destination=csvlog) — you can then import the data to the database and then filter out the queries you are not interested in:
Using CSV-Format Log Output
I have the following setting in my postgresql.conf
log_statement='all'
log_duration=on
When I run psql, and run any query like select/create user/ etc, it logs the statement as well as the duration. If I give the query to connect to a different database
\c <database_name>
it logs neither the duration nor the statement. I thought it might not log duration and statement for meta-commands that starts with a backslash. But it does log the statement and duration for some of them, like \dt \l.
I think there might be a list of queries/commands, for which log will be generated or not. is there any such list?
Having said that, the original issue, that led me to dig this is --
My application (golang-react application) interacts with postgresql and logs statement and its duration. But after that it logs two more durations, whose statement is not printed. (I have commented log_min_duration_statement), so I'm not sure what queries, this duration is for.
Also if I do SELECT query,xact_start,query_start FROM pg_stat_activity; at that time to see the running queries,it does not show any other query than the one which I see in the logs.
How can I know which queries is this duration for?
But after that it logs two more durations, whose statement is not printed.
These are probably the parse, bind and execute durations for the three phases of statement execution, if you have log_duration = on. It's only done in three phases via client applications - psql runs in a single go.
If you just want the total, use log_min_duration_statement = 0 instead.
Yes, that's confusing. Maybe it's worth writing it up and submitting it as a usability problem report to pgsql-general.
My application uses PostgreSQL for storing data. I need to gather information about all user actions (any INSERTs, UPDATEs or DELETEs) executed on the database. This made me wonder whether PostgreSQL provides any default implementations/tables for this? As per my prior searches, I haven't found anything usable yet - however proper confirmation to my suspicions would be nice. If PostgreSQL truly doesn't provide any default implementations for this, then I will design my own history table.
PostgreSQL supports several methods for logging server messages, including stderr, csvlog and syslog. On Windows, eventlog is also supported. Set this parameter to a list of desired log destinations separated by commas. The default is to log to stderr only. This parameter can only be set in the postgresql.conf file or on the server command line.
SEE HERE