MySQL General query logs

MySQL prints each query in General query logs. This can be helpful in application profiling if you want to see how many and which queries are being run in a transaction and when commit/rollback is executed. You can enable MySQL general query logs by running below sql command from root user: By default, logs will be stored at /var/log/query.log …

Increase MySQL maximum connection limit

MySQL’s default configuration sets the maximum concurrent connections to 151. If you get a too many connections error when you are trying to connect to MySQL server, this means that all available connections are in use by other clients / Users. The number of connections permitted is controlled by the max_connections system variable. Its default value …

kill a running query in postgres

There are queries which takes more times to execute. Sometimes you need to stop the queries but you can't do it simply(Ctrl+c) because queries are coming from application. There are mainly two approaches to kill the query. You can find the process corresponding to the query & kill or you can find the procpid of …

Django – AttributeError: ‘Http404’ object has no attribute ‘status_code’

If you getting this error, it might be because you are returning Http404 instead of raising it. you need to raise django.http.Http404, not return it. example code :

MySQL query with the conditions as ‘NOT LIKE IN’

While working with MySQL database i needed to write a query which will exclude rows where a column contains one or more words from a set of words. i.e I want to fetch data from student from table where name doesn't contain words shashank,john etc. Initially i was trying to write a query like this  : …

Interview Question of the Week #003 – How to Write Script for Database Cursor?

switching back to text console error during centos installation

I was trying to dual-boot CentOS 6 on my laptop that is currently running Windows 8. I have two storage devices, an SSD that has my Windows installation, and an HDD that has all of my data. Both are formatted using GPT, and Windows boots using UEFI. I used the CentOS 6.5 live CD (CentOS-6.5-x86_64-LiveCD.iso) …

PHP cURL

cURL Requests with PHP CURL is a way you can hit a URL from your code to get a HTML response from it. cURL means client URL which allows you to connect with other URLS and use there responses in your code. Introduction cURL allows transfer of data across a wide variety of protocols, and …

Disable an index in postgres

If you have got one index on a table that you would like to temporarily disable you can do following steps. You can poke the system catalogue to disable an index: This means that the index won't be used for queries but will still be updated. It's one of the flags used for concurrent index …

‘ascii’ codec can’t encode characters : ordinal not in range(128)

I work on a system which fetches data from a database (Postgres) using python & writes them into a csv file. Few days ago i came through an error which was showing "ascii codec can't encode characters : ordinal not in range(128)" whenever i tried to fetch data from a particular date range. Problem :  …