I'm trying to analyze my MySql database and server and when looking in phpmyadmin Status->Query statistics I can see that these three queries are the most used:
set option 31.91%
change db 15.71%
show variables 15.83%
I'm quite a newbie in MySql and my question is now: Why are these queries running so often? SELECT, INSERT, UPDATE and DELETE are not at all that frequently running on the server. I just wanted to see if this is normal behavior?
Thanks for your help!
It probably depends on the amount that you use phpMyAdmin vs running actual queries. My guess is that set option, change db, and show variables are used pretty often by phpMyAdmin.
Related
I'm working with a MySQL table through MySQL Workbench. Currently, many of my tables are appearing more than once with some appearing 10+ times. It is not messing anything up with my application or when I run a query on any of these tables, but something that I feel should be fixed. Haven't been able to find anything and just assuming this is a quick fix.
MySQL Table List
Currently running MySQL Workbench 8.0.23 build 365764 SE (64 bits), MySQL Azure Database System.
Also, is there any reason that this would be happening? I have a variety of php files set up to read/write data, my hunch is that some lines of code may be creating duplicates that I need to nail down, is there any specific SQL syntax that would be creating these duplicates (other than CREATE TABLE..., I do not have anything of that nature set to run).
Thanks for the help.
I have a database that was compromised. It's a very big content table and I don't know if any of the rows were altered. Is there a way in MySQL to see which rows were edited and when?
If it was compromised by injection you have to crawl through HTTP server's access log. MySQL has a query logging ability but it's "always" disabled since it seriously slows down the server. Otherwise: No.
You can use The General Query Log to track down the queries if its not turned off. For future you can use this steps mentioned in answer to set the query log How to show the last queries executed on MySQL?.
i have mysql that is used on production server for php webshop application.
sometimes it works very slow. so, i will change indexes for several tables.
but before that, i have to make some kind of "snapshot" of current performances (several times per day). after that, i will change indexes, and create new "performance snapshot". then i will made some more changes in database, and made another "performance snapshot".
how can i make that "performance snapshot"? is it possible to use some kind of tool, or to ckeck some logs, or...?
if you can help me how to do that.
thank you in advance!
If you want to buy a commercial product, there is the MySQL Query Analyzer
Otherwise, you could use the SQL Profiler which is already included with MySQL.
The SQL Profiler is built into the database server and can be dynamically enabled/disabled via the MySQL client utility. To begin profiling one or more SQL queries, simply issue the following command:
mysql> set profiling=1;
Thereafter, you will see the duration of each of your queries as you run them.
Slow query log and queries not using indexes
query cache hit rate
innodb monitor
and of course your database hard-disk I/O, memory usage ...
I'm an mssql veteran who's received a job that involves tuning a mysql db. with mssql it was simply a matter of firing up the db profiler and then crunching up the data it collects. I can't seem to find anything similar for mysql.
thanks in advance
You can enable the PROFILER in the mysql query tool and profile individual statements. Also see Using the New MySQL Query Profiler or How to profile a query in MySQL.
You can also use EXPLAIN to get the query optimization plan, but it only works for SELECT queries.
I have table in a SQL Server database with only 900 record with 4 column.
I am using Linq-to-SQL. Now I am trying retrieve data from that table for this I have written a select query.
Its not querying data from database and its showing time out error.
Please give me idea for this. First how can I increase time and second how can increase performance of query so can it easily access.
Thanks
That is a tiny table, there is either something very wrong with your database, or your application.
Try seeing what is happening in the database with SQL Profiler.
If you have just 900 records and four columns then unless you are storing many megabytes of data in each field the query should be very fast. I think your problem is that the connection is failing, possibly due to a firewall or other networking problem.
To debug I'd suggest running a simpler query and see if you can get any data at all. Also try running the same query from the SQL Server Management Studio to see if it works there.