Useful tips for everyday
Is NULL and NULL same? It’s important to note, that NULL doesn’t equal NULL. NULL is not a value, and therefore cannot be compared to…
How do I start mongos? Start a mongos using either a configuration file or a command line parameter to specify the config servers. If using…
What causes replication lag in Amazon RDS for MySQL? Amazon RDS for MySQL uses asynchronous replication. This means that sometimes, the replica isn’t able to…
How do I optimize a postgresql query? Query Tuning Eliminate Sequential Scans (Seq Scan) by adding indexes (unless table size is small) If using a…
How do I use distinct in SELECT? The SELECT DISTINCT statement is used to return only distinct (different) values. Inside a table, a column often…
How to see system tables in Oracle? You can see the list of objects by using this query: SELECT * FROM sys. dba_tab_privs WHERE grantee=’PUBLIC’;…
What can you not do in a filtered index? What You Can’t do in a Filtered Index… Create filtered indexes in SQL Server 2005. Use…
Can a SQL query alter a database? In SQL, we can alter or change the name of the SQL database either by using ALTER DATABASE…
How to join dynamic query with static query? Use temp tables & have the records dumped into it (from the dynamic query) & use the…
How can you change a column data type in PostgreSQL? PostgreSQL – Change Column Type First, specify the name of the table to which the…