Lab Sql

If I run the following SQL query SELECT * FROM A LEFT JOIN B ON A.foo=B.foo WHERE A.date = 'Ye… Read more Sql Order Of Operations

We see an issue occasionally. Stored procedure running a SQL runs very slow. Same SQL when run fro… Read more Db2 Luw 10.5 - How To Force Db2 Stored Procedures To Use Latest Stats For Most Optimized Plan

Say I have 2 functions using third one. Say function check_permission(user_id) is used by get_compa… Read more Postgresql Function Execution Plan Cache Principle

I'm experiencing a strange behaviour in a specific query in the SQL Server 2008 R2. I've go… Read more A Query That Does A Lot Of Reads, But Plan Is Ok

I have a SQL database server and 2 databases under it with the same structure and data. I run the s… Read more The Same Sql Query Takes Longer To Run In One Db Than Another Db Under The Same Server

Is there any difference? I know SQL queries are having their execution plans cached just as good as… Read more Postgresql Performance Of Ad-hoc Sql Vs Functions

In PostgreSQL, I have an index on a date field on my tickets table. When I compare the field agains… Read more Efficient Postgresql Query On Timestamp Using Index Or Bitmap Index Scan?

I have a table and data like this: create table AmountObjects ( objectId integer, unixTimestamp… Read more How Do Not Scan All Records To Query Top Rows By Complex Condition