Introduction We are comfortable with inserting/deleting record(s) into/from a table. But we sometimes get confused when we need to insert or delete records conditionally from a table. Let us look at an example. Example scenario Suppose we have a table, called ALL_EMPLOYEES, which contains all employees' information who are working or had ever worked for […]
By this stage, you should be familiar with the basics of SQL Server indexes. We've discussed what an Index actually is, as well as some of the most common types you're likely to encounter. Now that we've seen some simple examples of how Indexes can be useful, we're going to delve deeper into nonclustered indexes, as we'll see how they can improve the performance of more complex queries.
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We are reaching out to all people that enjoyed SQL Saturday in LA 2017, 2018, 2019, and 2020 events to let you know that the 2021 event is fast approaching. Only 30+ days remain until the June 12 Virtual Data.SQL.Saturday.LA event. Please register soon to reserve your spot by using http://2021sqlsatla.eventbrite.com/ hyperlink, register using a form below or just use a QR code.
Introduction Every DML transaction reads the data before it makes any changes. Not only during a SELECT query, but when you run any DML statement, insert, update, or delete, SQL Server first fetches a bunch of pages into the buffer pool locating the desired rows and changes them while synchronously writing to the transaction log […]
How to extend the range of SQL code analysis, during database development, to include dynamic analysis of the database metadata. This will allow regular checks for problems with the design of your tables and indexes ("table smells") that can affect database performance and data integrity.